Guide: Setting up RDF validation

Track

Test bed setup

This guide walks you through the points to consider when setting up validation for RDF and the steps to bring your validation service online. RDF content can be validated through various means; the current guide focuses on validation through SHACL shapes.

What you will achieve

At the end of this guide you will have understood what you need to consider when starting to implement validation services for your RDF vocabulary. You will also have gone through the steps to bring it online and make it available to your users.

An RDF validation service can be created using multiple approaches depending on your needs. You can have an on-premise (or local to your workstation) service through Docker or use the test bed’s resources and, with minimal configuration, bring online a public service that is automatically kept up-to-date.

For the purpose of this guide you will be presented the options to consider and start with a Docker-based instance that could be replaced (or complemented) by a setup through the test bed. Interestingly, the configuration relevant to the validator is the same regardless of the approach you choose to follow.

What you will need

  • About 30 minutes.

  • A text editor.

  • A web browser.

  • Access to the Internet.

  • Docker installed on your machine (only if you want to run the validator as a Docker container).

  • A basic understanding of RDF and SHACL shapes.

How to complete this guide

The steps described in this guide are for the most part hands-on, resulting in you creating a fully operational validation service. For these practical steps there are no prerequisites and the content for all files to be created are provided in each step. In addition, if you choose to try your setup as a Docker container you will also be issuing commands on a command line interface (all commands are provided and explained as you proceed).

Steps

You can complete this guide by following the steps described in this section. Not all steps are required, with certain ones being optional or complementary depending on your needs. The following diagram presents an overview of all steps highlighting the ones that apply in all cases (marked as mandatory):

../_images/step_overview3.png

When and why you should skip or consider certain steps depends on your testing needs. Each step’s description covers the options you should consider and the next step(s) to follow depending on your choice.

Step 1: Determine your testing needs

Before proceeding to setup your validator you need to clearly determine your testing needs. A first outline of the approach to follow would be provided by answering the following questions:

  • Will the validator be available to your users as a tool to be used on an ad-hoc basis?

  • Do you plan on measuring the conformance of your community’s members to the RDF-based specification?

  • Is the validator expected to be used in a larger conformance testing context (e.g. during testing of a message exchange protocol)?

  • Should the validator be publicly accessible?

  • Should test data and validation reports be treated as confidential?

The first choice to make is on the type of solution that will be used to power your validation service:

  • Standalone validator: A service allowing validation of individual RDF document instances based on a predefined configuration of SHACL shapes for business rule validation. The service supports fine-grained customisation and configuration of different validation types (e.g. specification versions) and supported communication channels. Importantly, use of the validator is anonymous and it is fully stateless in that none of the test data or validation reports are stored after validation completes.

  • Complete test bed: The test bed is used to realise a full conformance testing campaign. It supports the definition of test scenarios as test cases, organised in test suites that are linked to specifications. Access is account-based allowing users to claim conformance to specifications and execute in a self-service manner their defined test cases. All results are recorded to allow detailed reporting, monitoring and eventually certification. Test cases can address RDF validation but are not limited to that, allowing validation of any complex exchange of information.

It is important to note that these two approaches are by no means exclusive. It is often the case that a standalone validator is defined as a first step that is subsequently used from within test cases in the test bed. The former solution offers a community tool to facilitate work towards compliance supporting ad-hoc data validation, whereas the latter allows for rigorous conformance testing to take place where proof of conformance is required. This could apply in cases where conformance is a qualification criterion before receiving funding or before being accepted as a partner in a distributed system.

Regardless of the choice of solution, the next point to consider will be the type of access. If public access is important then the obvious choice is to allow access over the Internet. An alternative would be an installation that allows access only through a restricted network, be it an organisation’s internal network or a virtual private network accessible only by your community’s members. Finally, an extreme case would be access limited to individual workstations where each community member would be expected to run the service locally (albeit of course without the expectation to test message exchanges with remote parties).

If access to your validation services over the Internet is preferred or at least acceptable, the simplest case is to opt for using the shared DIGIT test bed resources, both regarding the standalone validator and the test bed itself. If such access is not acceptable or is technically not possible (e.g. access to private resources is needed), the proposed approach would be to go for a Docker-based on-premise installation of all components.

Summarising the options laid out in this section, you will first want to choose:

  • Whether you will be needing a standalone validator, a complete test bed or both.

  • Whether the validator and/or test bed will be accessible over the Internet or not.

Your choices here can help you better navigate the remaining steps of this guide. Specifically:

Step 2: Prepare validation artefacts

As an example case for RDF validation we will consider a variation of the EU purchase order case first seen in Guide: Creating a test suite. In short, for the purposes of this guide you are considered to be leading an EU cross-border initiative to define a new common specification for the exchange of purchase orders between retailers.

To specify the content of purchase orders your experts have created the following vocabulary:

@prefix owl: <http://www.w3.org/2002/07/owl#> .
@prefix dc: <http://purl.org/dc/terms/> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .

<http://itb.ec.europa.eu/sample/po#>
  a owl:Ontology ;
  dc:title "EU Purchase Orders" ;
  dc:description "An example ontology for EU Purchase Orders" .

#
# Classes
#

<http://itb.ec.europa.eu/sample/po#PurchaseOrder>
  a rdfs:Class ;
  rdfs:label "PurchaseOrder"@en ;
  rdfs:isDefinedBy <http://itb.ec.europa.eu/sample/po#> ;
  rdfs:subClassOf rdfs:Resource ;
  dc:identifier "po:PurchaseOrder" .

<http://itb.ec.europa.eu/sample/po#Item>
  a rdfs:Class ;
  rdfs:label "Item"@en ;
  rdfs:isDefinedBy <http://itb.ec.europa.eu/sample/po#> ;
  rdfs:subClassOf rdfs:Resource ;
  dc:identifier "po:Item" .

#
# PurchaseOrder properties
#

<http://itb.ec.europa.eu/sample/po#shipTo>
  a rdf:Property ;
  rdfs:label "shipTo"@en ;
  rdfs:isDefinedBy <http://itb.ec.europa.eu/sample/po#> ;
  rdfs:domain <http://itb.ec.europa.eu/sample/po#PurchaseOrder> ;
  rdfs:range <http://www.w3.org/ns/locn#Address> ;
  rdfs:subPropertyOf <http://www.w3.org/ns/locn#address> ;
  dc:identifier "po:shipTo" .

<http://itb.ec.europa.eu/sample/po#billTo>
  a rdf:Property ;
  rdfs:label "billTo"@en ;
  rdfs:isDefinedBy <http://itb.ec.europa.eu/sample/po#> ;
  rdfs:domain <http://itb.ec.europa.eu/sample/po#PurchaseOrder> ;
  rdfs:range <http://www.w3.org/ns/locn#Address> ;
  rdfs:subPropertyOf <http://www.w3.org/ns/locn#address> ;
  dc:identifier "po:billTo" .

<http://itb.ec.europa.eu/sample/po#hasItem>
  a rdf:Property ;
  rdfs:label "hasItems"@en ;
  rdfs:isDefinedBy <http://itb.ec.europa.eu/sample/po#> ;
  rdfs:domain <http://itb.ec.europa.eu/sample/po#PurchaseOrder> ;
  rdfs:range <http://itb.ec.europa.eu/sample/po#Item> ;
  dc:identifier "po:hasItem" .

#
# Item properties
#

<http://itb.ec.europa.eu/sample/po#productName>
  a rdf:Property ;
  rdfs:label "productName"@en ;
  rdfs:isDefinedBy <http://itb.ec.europa.eu/sample/po#> ;
  rdfs:domain <http://itb.ec.europa.eu/sample/po#Item> ;
  rdfs:range rdfs:Literal ;
  dc:identifier "po:productName" .

<http://itb.ec.europa.eu/sample/po#quantity>
  a rdf:Property ;
  rdfs:label "quantity"@en ;
  rdfs:isDefinedBy <http://itb.ec.europa.eu/sample/po#> ;
  rdfs:domain <http://itb.ec.europa.eu/sample/po#Item> ;
  rdfs:range xsd:positiveInteger ;
  dc:identifier "po:quantity" .

<http://itb.ec.europa.eu/sample/po#price>
  a rdf:Property ;
  rdfs:label "price"@en ;
  rdfs:isDefinedBy <http://itb.ec.europa.eu/sample/po#> ;
  rdfs:domain <http://itb.ec.europa.eu/sample/po#Item> ;
  rdfs:range xsd:decimal ;
  dc:identifier "po:price" .

This vocabulary defines the basic properties for an order’s items (product name, quantity and price in euros) and also a shipping and billing address for which the Core Location Vocabulary has been reused. The syntax used to express the vocabulary in this example is Turtle. You can download this here in the displayed Turtle format or in RDF/XML.

Based on this, a sample purchase order could be expressed in Turtle as follows:

@prefix ns0: <http://www.w3.org/ns/locn#> .
@prefix ns1: <http://itb.ec.europa.eu/sample/po#> .

<http://my.sample.po/po#purchaseOrder>
  a <http://itb.ec.europa.eu/sample/po#PurchaseOrder> ;
  ns1:shipTo <http://my.sample.po/po#home> ;
  ns1:billTo <http://my.sample.po/po#home> ;
  ns1:hasItem <http://my.sample.po/po#item1>;
  ns1:hasItem  <http://my.sample.po/po#item2> .

<http://my.sample.po/po#home>
  a <http://www.w3.org/ns/locn#Address> ;
  ns0:fullAddress "Rue du Test 123, 1000 - Brussels, Belgium" ;
  ns0:thoroughfare "Rue du Test" ;
  ns0:locatorDesignator "123" ;
  ns0:postCode "1000" ;
  ns0:postName "Brussels" ;
  ns0:adminUnitL1 "BE" .

<http://my.sample.po/po#item1>
  a ns1:Item ;
  ns1:productName "Mouse" ;
  ns1:quantity 20 ;
  ns1:priceEUR 15.99 .

<http://my.sample.po/po#item2>
  a ns1:Item ;
  ns1:productName "Keyboard" ;
  ns1:quantity 15 ;
  ns1:priceEUR 25.50 .

Given the inherent flexibility of RDF, your experts have chosen to add certain business rule restrictions as SHACL shapes that would apply to all purchase orders. The implemented rules ensure that:

  • Only a single shipping address is defined.

  • An optional billing address can be defined (the shipping address is considered as the default).

  • An order includes at least one item.

  • All items define their product name, quantity and price.

@prefix po:  <http://itb.ec.europa.eu/sample/po#> .
@prefix locn: <http://www.w3.org/ns/locn#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
@prefix sh:  <http://www.w3.org/ns/shacl#> .

#
# Rules for purchase orders
#

po:PurchaseOrderShape
	a sh:NodeShape ;
	sh:targetClass po:PurchaseOrder ;
	sh:property po:shipToShape ;
	sh:property po:billToShape ;
	sh:property po:hasItemsShape .

po:shipToShape
	a sh:PropertyShape ;
	sh:path po:shipTo ;
	sh:minCount 1 ;
	sh:maxCount 1 ;
	sh:class locn:Address ;
	sh:severity sh:Violation .

po:billToShape
	a sh:PropertyShape ;
	sh:path po:billTo ;
	sh:class locn:Address ;
	sh:maxCount 1 ;
	sh:severity sh:Violation .

 po:hasItemsShape
 	a sh:PropertyShape ;
	sh:path po:hasItem ;
	sh:minCount 1 ;
	sh:class po:Item ;
	sh:severity sh:Violation .

#
# Rules for purchase order items
#

po:ItemShape
	a sh:NodeShape ;
	sh:targetClass po:Item ;
	sh:property po:productNameShape ;
	sh:property po:quantityShape ;
	sh:property po:priceShape .

po:productNameShape
	a sh:PropertyShape ;
	sh:path po:productName ;
	sh:minCount 1 ;
	sh:maxCount 1 ;
	sh:nodeKind sh:Literal ;
	sh:severity sh:Violation .

po:quantityShape
	a sh:PropertyShape ;
	sh:path po:quantity ;
	sh:minCount 1 ;
	sh:maxCount 1 ;
	sh:datatype xsd:integer ;
	sh:minExclusive 0 ;
	sh:severity sh:Violation .

po:priceShape
	a sh:PropertyShape ;
	sh:path po:priceEUR ;
	sh:minCount 1 ;
	sh:maxCount 1 ;
	sh:datatype xsd:decimal ;
	sh:severity sh:Violation .

All purchase orders will need to validate against the above SHACL shapes. However, your business requirements also define the concept of a large purchase order which is one that includes more than 10 of each ordered item. To implement this restriction an additional SHACL shape is defined to be considered in addition to the common ones for orders that are supposed to be “large”. Such a SHACL shape file would be as follows:

@prefix po:  <http://itb.ec.europa.eu/sample/po#> .
@prefix sh:  <http://www.w3.org/ns/shacl#> .

#
# Rule for large purchase orders
#

po:LargeItemShape
	a sh:NodeShape ;
	sh:targetClass po:Item ;
	sh:property po:minimumItemsForLargeOrderShape .

po:minimumItemsForLargeOrderShape
	a sh:PropertyShape ;
	sh:path po:quantity ;
	sh:minExclusive 10 ;
	sh:severity sh:Violation .

Given these requirements and validation artefacts we want to support two types of validation (or profiles):

  • basic: For all purchase orders acting as a common base. This is realised by validating against the common SHACL shapes.

  • large: For large purchase orders. This includes validation against the common SHACL shapes and the additional one defined for large orders.

As the first configuration step for the validator we will prepare a folder with the required resources. For this purpose create a root folder named validator with the following subfolders and files:

validator
└── resources
    └── order
        └── shapes
            ├── PurchaseOrder-common-shapes.ttl
            └── PurchaseOrder-large-shapes.ttl

You will likely note that we are creating several folders of no obvious use. Nonetheless please follow this structure as it will facilitate subsequent steps where we add resources depending on our needs. In terms of meaning of these folders consider the following:

  • validator is the root folder for all files.

  • resources is the root folder for all files that will be considered by the validator.

  • order is the root folder for all files pertinent to purchase order validation. We separate this as the validator could be used to also validate completely different content.

  • shapes is the folder containing all SHACL shape files.

Regarding the PurchaseOrder-common-shapes.ttl and PurchaseOrder-large-shapes.ttl files you can create them from the above content or download them (here: PurchaseOrder-common-shapes.ttl and PurchaseOrder-large-shapes.ttl). Finally, note that you are free to use any names for the files and folders; the ones used here will however be the ones considered in this guide’s subsequent steps.

Note

Validate your shapes: When authoring your SHACL shapes you should validate them against best practices and the SHACL specification. This adds a quality check over the shapes before you start using them for validation.

The Test Bed offers a SHACL shape validator for this purpose at https://www.itb.ec.europa.eu/shacl/shacl/upload.

Step 3: Prepare validator configuration

After having defined your testing needs and the validation artefacts for your specific case, the next step will be to configure the validator. The validator is defined by a core engine maintained by the test bed team and a layer of configuration, provided by you, that defines its use for a specific scenario. In terms of features the validator supports the following:

  • Validation channels including a REST web service API, a SOAP web service API, a web user interface and a command-line tool.

  • Configuration of SHACL shapes to drive the validation that can be local or remote.

  • Definition of different validation types as logically-related sets of validation artefacts.

  • Support per validation type allowing user-provided SHACL shape extensions.

  • Support per validation type of loading the imports defined in the input that can also be set by users at validation time.

  • Support for querying SPARQL endpoints to retrieve the content to validate.

  • Definition of separate validator configurations that are logically split but run as part of a single validator instance. Such configurations are termed “validation domains”.

  • Customisation of all texts presented to users.

Configuration is provided by means of key-value pairs in a property file. This file can be named as you want but needs to end with the .properties extension. In our case we will name this config.properties and place it within the order folder. Recall that the purpose of this folder is to store all resources relevant to purchase order validation. These are the validation artefacts themselves (PurchaseOrder-common-shapes.ttl and PurchaseOrder-large-shapes.ttl) and the configuration file (config.properties).

Define the content of the config.properties file as follows:

# The different types of validation to support. These values are reflected in other properties.
validator.type = basic, large
# Labels to describe the defined types.
validator.typeLabel.basic = Basic purchase order
validator.typeLabel.large = Large purchase order
# Validation artefacts (SHACL shapes) to consider for the "basic" type.
validator.shaclFile.basic = shapes/PurchaseOrder-common-shapes.ttl
# Validation artefacts (SHACL shapes) to consider for the "large" type.
validator.shaclFile.large = shapes/PurchaseOrder-common-shapes.ttl, shapes/PurchaseOrder-large-shapes.ttl
# The title to display for the validator's user interface.
validator.uploadTitle = Purchase Order Validator

All validator properties share a validator. prefix. The validator.type property is key as it defines one or more types of validation that will be supported (multiple are provided as a comma-separated list of values). The values provided here are important not only because they define the available validation types but also because they drive most other configuration properties. Regarding the validation artefacts themselves, these are provided by means of the validator.shaclFile property, specifically:

  • validator.shaclFile.TYPE defines one or more (comma-separated) file paths (relative to the configuration file) to lookup SHACL shape files.

  • validator.shaclFile.TYPE.remote.N can be defined multiple times for SHACL files that are to be loaded remotely (e.g. from a GitHub repository).

Regarding local files (i.e. using the validator.shaclFile.TYPE property) each provided path can be for a file or a folder. If a folder is referenced it will load all contained top-level files (i.e. ignoring subfolders). Regarding remotely loaded files (i.e. the validator.shaclFile.TYPE.remote.N) you may define as many of these as the number of files to load (the N placeholder is a zero-based integer). In addition, for each remotely loaded file we need to also specify its syntax, provided as its mime type. This can be omitted if the syntax can be derived by the file’s extension (e.g. Turtle for .ttl), but it is a good practice to always define this for consistency.

The example that follows illustrates the loading of two remote SHACL shape files for a validation type named v2.2.1 from a remote location:

validator.type = v2.2.1
...
validator.shaclFile.v2.2.1.remote.0.url = https://my.server.com/my_rules_1.ttl
validator.shaclFile.v2.2.1.remote.0.type = text/turtle
validator.shaclFile.v2.2.1.remote.1.url = https://my.server.com/my_rules_2.rdf
validator.shaclFile.v2.2.1.remote.1.type = application/rdf+xml

In case remote shape files fail to be retrieved, you may choose to report this to your users. This is achieved by using property validator.remoteArtefactLoadErrors.TYPE to adapt this for a given validation type, or validator.remoteArtefactLoadErrors to set your default approach (see Domain-level configuration). In case your shape files define owl:imports you may define similar handling to manage errors while loading the imported resources. The configuration properties to use in this case are validator.owlImportErrors.TYPE (for configuration relative to a given validation type) and validator.owlImportErrors (for your default handling). In all cases, the values you may set are:

  • fail, to log the error, immediately stop validation and report this as an error to the user.

  • warn, to log the error, continue validation, but display a warning to the user that the results may be incomplete.

  • log, considered by default, to log the error but continue validation normally without notifying the user.

If third party shape files use themselves owl:imports, you may encounter errors if their URIs cannot be resolved. As you don’t directly control these imports, and furthermore if these are not important to your own validations, you may choose to either completely skip certain URIs or ignore their load errors. Specifically you may configure the following properties:

  • validator.owlImportSkippedUris, to completely skip the import of the configured URIs.

  • validator.owlImportErrorsIgnoredUris, to attempt the URIs’ import but not report any failures to users (as errors or warning messages).

In both cases, the URIs to consider are provided as comma-separated lists:

...
validator.owlImportSkippedUris = http://uritoskip1.com/resource, http://uritoskip2.com/resource
validator.owlImportErrorsIgnoredUris = http://uritoignore1.com/resource, http://uritoignore2.com/resource

Note

Regardless of how import errors are treated, all URIs that were not skipped and resulted in a failure, are logged as warnings in the browser’s console (when using the validator via its user interface).

You may combine local and remote SHACL shape files by defining a validator.shaclFile.TYPE property and one or more validator.shaclFile.TYPE.remote.N properties. In all cases, the shapes from all sources will be aggregated into a single model for the validation.

Note

Remote SHACL shape caching: Caching is used to avoid constant lookups of remote SHACL shape files. Once loaded, remote SHACL shape files will be automatically refreshed every hour.

In addition, apart from defining the SHACL shapes to apply as local and/or remote files, you may also define for a given validation type whether or not you allow user-provided SHACL shape extensions. This is achieved through the validator.externalShapes property:

...
validator.externalShapes.TYPE = optional

Specifying that for a given validation type you allow users to provide SHACL shape extensions will result in any such extensions being combined with your pre-defined SHACL shapes. This could be useful in scenarios where you want to define a common validation base but allow also ad-hoc extensions for e.g. restrictions defined at user-level (e.g. National validation rules to consider in addition to a common set of EU rules).

Note

Generic validator: It is possible to not predefine any SHACL shapes resulting in a validator that is truly generic, expecting all shapes to be provided by users. Such a generic instance actually exists at https://www.itb.ec.europa.eu/shacl/any/upload.

The purpose of the remaining properties is to customise the text descriptions presented to users:

  • validator.typeLabel defines a label to present to users on the validator’s user interface for the type in question.

  • validator.uploadTitle defines the title label to present to users on the validator’s user interface.

Once you have created the config.properties file, the validator folder should be as follows:

validator
└── resources
    └── order
        ├── shapes
        │   ├── PurchaseOrder-common-shapes.ttl
        │   └── PurchaseOrder-large-shapes.ttl
        └── config.properties

This limited configuration file assumes numerous default configuration properties. An important example is that by default, the validator will expose a web user interface, a SOAP web service API and a REST API. This configuration is driven through the validator.channels property that by default is set to form, rest_api, soap_api (for a user form, REST API and SOAP web service respectively). All configuration properties provided in config.properties relate to the specific domain in question, notably purchase orders, reflected in the validator’s resources as the order folder. Although rarely needed, you may define additional validation domains each with its own set of validation artefacts and configuration file (see Configuring additional validation domains for details on this). Finally, if you are planning to host your own validator instance you can also define configuration at the level of the complete validator (see Additional configuration options regarding application-level configuration options).

For the complete reference of all available configuration properties and their default values refer to section Validator configuration properties.

Supporting options per validation type

The different types of validation supported by the validator (enumerated using property validator.type) determine the different kinds of validation that your users may select. Available types are listed in the validator’s web user interface in a dropdown list, and need to be provided as input when executing a validation.

It could be the case that your validator needs to support an extra level of granularity over the validation types. This would apply if each validation type has itself a set of additional options that actually define the specific validation to take place. For example, a validator for a specification defining rules for different types of data structures, may need to also allow users to select the desired version number. In this case we would define:

  • As validation types, the specification’s foreseen data structures.

  • As validation type options, the version numbers for each data structure.

Configuring such options can greatly simplify a validator’s configuration given that certain common data needs to be defined only once. In addition, the validator’s user interface becomes much more intuitive by listing two dropdowns in place of one: the first one to select the validation type, and the second one to select it’s specific option. The alternative, simply configuring all combinations as separate validation types, would render the validator less intuitive and more difficult to maintain.

Options are defined per validation type using validator.typeOptions.TYPE properties, for which the applicable options are defined as a string with comma-separated values. Once options are defined, most configuration properties that are specific to validation types now consider the full type as TYPE.OPTION (type followed by option and separated by .).

In terms of defining labels for options we can use:

  • validator.typeOptionLabel.TYPE.OPTION, for the label of an option specific to a given validation type.

  • validator.optionLabel.OPTION, for the label of an option that is the same across types.

  • validator.completeTypeOptionLabel.TYPE.OPTION, for a label to better express the combination of type plus option.

Revisiting our EU Purchase Order example we could add support for specification versions by configuring properties as follows (we skip defining labels as the option value suffices):

# Validation types
validator.type = basic, large
validator.typeLabel.basic = Basic purchase order
validator.typeLabel.large = Large purchase order
# Options
validator.typeOptions.basic = v1.2.0, v1.1.0, v1.0.0
validator.typeOptions.large = v1.1.0, v1.0.0
# Validation artefacts
validator.shaclFile.basic.v1.2.0 = shapes/v1.2.0/PurchaseOrder-common-shapes.ttl
validator.shaclFile.basic.v1.1.0 = shapes/v1.1.0/PurchaseOrder-common-shapes.ttl
validator.shaclFile.basic.v1.0.0 = shapes/v1.0.0/PurchaseOrder-common-shapes.ttl
validator.shaclFile.large.v1.1.0 = shapes/v1.1.0/PurchaseOrder-common-shapes.ttl, shapes/v1.1.0/shapes/PurchaseOrder-large-shapes.ttl
validator.shaclFile.large.v1.0.0 = shapes/v1.0.0/PurchaseOrder-common-shapes.ttl, shapes/v1.0.0/shapes/PurchaseOrder-large-shapes.ttl

Note

The configuration property reference specifies per property whether it expects the validation type, option or full type (validation type plus option) as part of its definition.

Configuring SPARQL query support

The way in which the validator receives the content to validate depends on the specific channel you are using (web UI, REST API, SOAP API or command-line tool). Regardless of how you use the validator, the content to validate can provided:

  • As an RDF file.

  • As a URI that will provide or generate the RDF content.

  • As direct input of RDF data.

A further option for input, that is not enabled by default, is to have the validator query a triple store through SPARQL queries. This approach allows you to store RDF data and dynamically select the parts to validate by passing to the validator the queries to execute. The queries used must be CONSTRUCT queries, which can return a complete data graph of data subset based on the query’s definition.

When configuring SPARQL query support for your validator you have several configuration options. You would typically preconfigure the SPARQL endpoint for your queries along with any credentials needed for authentication. Alternatively you could leave this information unspecified, allowing your users to define themselves the endpoint and the credentials to use. You could also only configure the endpoint, and expect users to provide personal authentication credentials if this matches your needs. Query-related configuration options are defined as part of a domain’s definition (see Domain-level configuration). The following sample configurations highlight how you would adapt your domain configuration file (config.properties) to use the relevant properties for different scenarios.

Example 1: Configure a SPARQL endpoint and require the user to provide personal credentials.

...
validator.queryEndpoint = http://host/sparql
# We don't specify credentials but mark them as required. Not doing so would default to them
# being considered as optional.
validator.queryAuthenticationInput = required

Example 2: Configure a SPARQL endpoint and the credentials to use (password provided via environment variable).

...
validator.queryEndpoint = http://host/sparql
# Configuring credentials will not allow users to provide their own.
validator.queryUsername = sparqlUser
validator.queryPassword = ${env:SPARQL_PASSWORD}

Example 3: Allow users to define any SPARQL endpoint and credentials.

...
# If this flag is not set to true the validator will not support queries.
# We didn't need to set this explicitly in the other examples as we already
# defined other query-related properties.
validator.supportsQueries = true

Note that the configuration discussed here only refers to you enabling SPARQL queries as an input to the validator. To see how these can be passed to the validator check the validator usage documentation.

Input pre-processing

An advanced configuration option available to you is to enable for a given validation type the pre-processing of the validator’s input. Pre-processing allows you to execute a SPARQL CONSTRUCT query on the input in order to transform it to be used for validation, rather than using the full original content. The typical use case for this is when the input content contains classes and statements that are not all relevant for the validation, or that need to be reshaped. In this case you can pre-process the input to produce a different graph as a result of filtering and adapting the original triples. Alternatively, you may have separate validation types focusing on entirely different parts of the provided RDF content.

Pre-processing of the input can be configured in your validator by means of SPARQL CONSTRUCT query to be executed on the input for specific validation types. Once your validator receives the RDF input for a given validation type, it will check to see whether a SPARQL CONSTRUCT query is defined for that type to pre-process the input before validating. Configuring input pre-processing queries is done through validator.input.preprocessor.TYPE properties in your domain configuration file.

For example if you have Turtle content such as the following:

@prefix ns0: <http://www.w3.org/ns/locn#> .
@prefix ns1: <http://itb.ec.europa.eu/sample/po#> .

<http://my.sample.po/po#purchaseOrder>
  a <http://itb.ec.europa.eu/sample/po#PurchaseOrder> ;
  ns1:shipTo <http://my.sample.po/po#home> ;
  ns1:billTo <http://my.sample.po/po#home> ;
  ns1:hasItem <http://my.sample.po/po#item1>;
  ns1:hasItem  <http://my.sample.po/po#item2> .

<http://my.sample.po/po#home>
  a <http://www.w3.org/ns/locn#Address> ;
  ns0:fullAddress "Rue du Test 123, 1000 - Brussels, Belgium" ;
  ns0:thoroughfare "Rue du Test" ;
  ns0:locatorDesignator "123" ;
  ns0:postCode "1000" ;
  ns0:postName "Brussels" ;
  ns0:adminUnitL1 "BE" .

<http://my.sample.po/po#item1>
  a ns1:Item ;
  ns1:productName "Mouse" ;
  ns1:quantity <http://my.sample.po/po#quantity2> ;
  ns1:priceEUR <http://my.sample.po/po#price1> .

<http://my.sample.po/po#item2>
  a ns1:Item ;
  ns1:productName "Keyboard" ;
  ns1:quantity <http://my.sample.po/po#quantity2> ;
  ns1:priceEUR <http://my.sample.po/po#price2> .

<http://my.sample.po/po#quantity1>
  a ns1:Quantity ;
  ns1:value 20.

<http://my.sample.po/po#quantity2>
  a ns1:Quantity ;
  ns1:value 15.

<http://my.sample.po/po#price1>
  a ns1:PriceEUR ;
  ns1:value 15.99 .

<http://my.sample.po/po#price2>
  a ns1:PriceEUR ;
  ns1:value 25.50 .

You could define a pre-processing query for the validation type address to transform the original content to an adapted input graph as follows:

...
validator.type = address, full
...
# Query to extract only addresses.
validator.input.preprocessor.address = PREFIX ns0:<http://www.w3.org/ns/locn#> CONSTRUCT { ?address a <http://www.w3.org/ns/locn#Address> ; ns0:fullAddress ?fullAddress1 ; ns0:thoroughfare ?tfare1 ; ns0:locatorDesignator ?ldes1 ; ns0:postCode ?postCode1 ; ns0:postName ?postName1 ; ns0:adminUnitL1 ?aunit1 . } WHERE { ?address a <http://www.w3.org/ns/locn#Address> ; ns0:fullAddress ?fullAddress1 ; ns0:thoroughfare ?tfare1 ; ns0:locatorDesignator ?ldes1 ; ns0:postCode ?postCode1 ; ns0:postName ?postName1 ; ns0:adminUnitL1 ?aunit1 . }
# No need to specify an expression for the "full" type as content will be validated as-is.

Supporting multiple languages

Certain configuration properties we have seen up to now define texts that are visible to the validator’s users. Examples of these include the title of the validator’s user interface (validator.uploadTitle) or the labels to present for the available validation types (validator.typeLabel.TYPE), which in the sample configuration are set with English values. Depending on your validator’s audience you may want to switch to a different language or support several languages at the same time. Supporting multiple languages affects:

  • The texts, labels and messages presented on the validator’s user interface.

  • The reports produced after validating content via any of the validator’s interfaces.

The text values used by default by the validator are defined in English (see default values here), with English being the language considered by the validator if no other is selected. If your validator needs to support only a single language, a simple approach is to ensure that the domain-level configuration properties for texts presented to users are defined in the domain configuration file with the values for your selected language. Note that as long as the validator’s target language is an EU official language you need not provide translations for user interface labels and messages as these are defined by the validator itself. You are nonetheless free to redefine these to override the defaults or to define them for a non-supported language.

In case you want your validator to support multiple languages at the same time you need to adapt your configuration to define the supported languages and their specific translations. To do this adapt your domain configuration property file making use of the following properties:

  • validator.locale.available: The list of languages to be supported by the validator, provided as a comma-separated list of language codes (locales). The order these are defined with determines their presentation order in the validator’s user interface.

  • validator.locale.default: The validator’s default language, considered if no specific language has been requested. If multiple languages are supported the default needs to be set to one of these.

  • validator.locale.translations: The path to a folder (absolute or relative to the domain configuration file) that contains the translation property files for the validator’s supported languages.

Each language (locale) is defined as a 2-character lowercase language code (based on ISO 639), followed by an optional 2-character uppercase country code (based on ISO 3166) separated using an underscore character (_). The format is in fact identical to that used to define locales in the Java language. Valid examples include “fr” for French, “fr_FR” for French in France, or “fr_BE” for French in Belgium. Such language codes are the values expected to be used for properties validator.locale.available and validator.locale.default.

Regarding property validator.locale.translations, the value is expected to be a folder containing the translation files for your selected languages. These are defined exactly as you would define a resource bundle in a Java program, specifically:

  • The names of all property files start with the same prefix. Any value can be selected with good examples being “labels” or “translations”.

  • The common prefix is followed by the relevant locale value (language code and country code) separated with an underscore.

  • The files’ extension is set as “.properties”.

Considering the above, good examples of translation property file names would be “labels_de.properties”, “labels_fr.properties” and “labels_fr_FR.properties”. Note that these files are implicitly hierarchical meaning that for related locales you need not redefine all properties. For example you may have your French texts defined in “labels_fr.properties” and only override what you need in “labels_fr_BE.properties”. You can also define an overall default translation file by omitting the locale in its name (labels.properties) which will be used when no locale-specific file exists or if it exists but does not include the given property key. Note additionally that if you define translatable text values in your main domain configuration file these are considered as overall defaults if no specific translations could be found in translation files.

In terms of contents, the translation files are simple property files including key-value pairs. Each such pair defines as its key the property key for the given text, with the value being the translation to use. The properties that can be defined in such files are:

Considering that you typically wouldn’t need to override labels and messages, the texts you would need to translate are the ones relevant to your specification. These are most often the following:

  • The title of the validator’s UI (validator.uploadTitle).

  • The UI’s HTML banner content (validator.bannerHtml), which can be customised as explained in Adding a custom banner and footer.

  • The descriptions for the validation types that you define and their options (validator.typeLabel.TYPE, validator.optionLabel.OPTION, validator.typeOptionLabel.TYPE.OPTION and validator.completeTypeOptionLabel.TYPE.OPTION).

The information up to this point covers the translation of texts, labels and messages but has not yet addressed the validator’s SHACL shapes. This is achieved by ensuring that each shape includes a set of sh:message entries, with one such message per supported language that defines the translation for the shape’s resulting message.

To illustrate how all this comes together let’s revisit our Purchase Order example. In our current, single-language and English-only setup, the configuration files are structured as follows:

validator
└── resources
    └── order
        ├── shapes
        │   ├── PurchaseOrder-common-shapes.ttl
        │   └── PurchaseOrder-large-shapes.ttl
        └── config.properties

The domain configuration file (config.properties) defines itself the user-presented texts (see highlighted lines):

validator.type = basic, large
validator.typeLabel.basic = Basic purchase order
validator.typeLabel.large = Large purchase order
validator.shaclFile.basic = shapes/PurchaseOrder-common-shapes.ttl
validator.shaclFile.large = shapes/PurchaseOrder-common-shapes.ttl, shapes/PurchaseOrder-large-shapes.ttl
validator.uploadTitle = Purchase Order Validator

In addition, our shapes do not include sh:message entries resulting in the default English messages. For example PurchaseOrder-large-shapes.ttl defines:

@prefix po:  <http://itb.ec.europa.eu/sample/po#> .
@prefix sh:  <http://www.w3.org/ns/shacl#> .

po:LargeItemShape
    a sh:NodeShape ;
    sh:targetClass po:Item ;
    sh:property po:minimumItemsForLargeOrderShape .

po:minimumItemsForLargeOrderShape
    a sh:PropertyShape ;
    sh:path po:quantity ;
    sh:minExclusive 10 ;
    sh:severity sh:Violation .

Starting from this point we will make the necessary changes to support alongside English (which remains the default language), German and French translations. The first step is to adapt the config.properties file to remove the contained translations. We could have kept these here for English but as we will be adding specific translation files it is cleaner to move all translations to them. The content of config.properties becomes now as follows:

validator.type = basic, large
validator.shaclFile.basic = shapes/PurchaseOrder-common-shapes.ttl
validator.shaclFile.large = shapes/PurchaseOrder-common-shapes.ttl, shapes/PurchaseOrder-large-shapes.ttl
validator.locale.available = en,fr,de
validator.locale.default = en
validator.locale.translations = translations

To define the translations we will introduce a new folder translations (as defined in property validator.locale.translations) that includes the property files per locale:

validator
└── resources
    └── order
        ├── shapes
        │   ├── PurchaseOrder-common-shapes.ttl
        │   └── PurchaseOrder-large-shapes.ttl
        ├── translations
        │   ├── labels_en.properties
        │   ├── labels_fr.properties
        │   └── labels_de.properties
        └── config.properties

The English translations are provided in labels_en.properties (these are simply moved here from the config.properties file):

validator.typeLabel.basic = Basic purchase order
validator.typeLabel.large = Large purchase order
validator.uploadTitle = Purchase Order Validator

French translations are defined in labels_fr.properties:

validator.typeLabel.basic = Bon de commande de base
validator.typeLabel.large = Bon de commande important
validator.uploadTitle = Validateur de bon de commande

And finally German translations are defined in labels_de.properties:

validator.typeLabel.basic = Grundbestellung
validator.typeLabel.large = Großbestellung
validator.uploadTitle = Bestellbestätigung

Finally, we must not forget to adapt our shape files to define explicit message translations. Taking as an example PurchaseOrder-large-shapes.ttl this is adapted as follows:

@prefix po:  <http://itb.ec.europa.eu/sample/po#> .
@prefix sh:  <http://www.w3.org/ns/shacl#> .

po:LargeItemShape
    a sh:NodeShape ;
    sh:targetClass po:Item ;
    sh:property po:minimumItemsForLargeOrderShape .

po:minimumItemsForLargeOrderShape
    a sh:PropertyShape ;
    sh:path po:quantity ;
    sh:minExclusive 10 ;
    sh:message "The quantities of items for large orders must be greater than 10."@en;
    sh:message "Les quantités d'articles pour les grosses commandes doivent être supérieures à 10."@fr;
    sh:message "Die Artikelmengen für Großbestellungen müssen größer als 10 sein."@de;
    sh:severity sh:Violation .

Note

Locale format in shapes: The locales defined in shapes differ slightly in that they use a dash (-) as opposed to an underscore (_) to separate language and country codes. For example a Belgian French variant would be defined as fr-BE as opposed to fr_BE.

This completes the validator’s localisation configuration. With this setup in place, the user will be able to select one of the supported languages to change the validator’s user interface and resulting report. Note that localised reports can also now be produced from the validator’s REST API, SOAP API and command-line tool.

Including additional information in report findings

Validating through the validator’s user interface or command-line tool produces apart from the SHACL validation report, additional reports meant primarily for use by humans. These reports include for each finding:

  • The finding’s severity level.

  • A description to explain why the finding was raised.

  • Information on the relevant location, including the relevant focus node and result path.

  • Information on the applied test, including the triggered shape and tested value.

This information corresponds to what is also available through the SHACL validation report.

To make these reports more meaningful, the validator allows you to include additional context information for each reported item. This context information can be defined in a flexible manner, allowing you to include arbitrary texts and values of one or more properties of the finding’s focus node. The information to include is provided in the configuration as a template expression to be evaluated during report generation for each finding, and may be localised for the validator’s different supported languages (if enabled).

To include such additional information per reported finding, you need to adapt your domain configuration file as per the following example:

# The template to generate the additional information text.
validator.reportItemAdditionalInfoTemplate = Product [${http://itb.ec.europa.eu/sample/po#productName}]

Property validator.reportItemAdditionalInfoTemplate defines a template expression to generate the additional information, which may include any fixed text and property value placeholders. These placeholders are defined in the form ${PROPERTY}, where PROPERTY is the URI of a specific property from your ontology. Each such property is looked up on the focus node referred to by the report item, with the resulting value replacing its placeholder. When referring to such properties you need to ensure that their text representation is meaningful and that they are indeed present for the focus node (otherwise empty values are used).

By default this additional information is included in each report item next to a Additional information: label. You may replace this label using the validator.label.additionalInfoLabel property if you wish to define one more specific to the information you are adding:

# The label to display in the report.
validator.label.additionalInfoLabel = Product:
# The template to generate the additional information text.
validator.reportItemAdditionalInfoTemplate = ${http://itb.ec.europa.eu/sample/po#productName}

In case your shapes target nodes of different types you may also provide a more extended configuration with templates per rdf:type. To do so you provide numbered pairs of configuration entries, specifying for each a template expression and the rdf:type to apply it for:

# Template configuration for focus nodes of type "http://itb.ec.europa.eu/sample/po#Item".
validator.reportItemAdditionalInfoTemplate.0.type = http://itb.ec.europa.eu/sample/po#Item
validator.reportItemAdditionalInfoTemplate.0.template = Product [${http://itb.ec.europa.eu/sample/po#productName}]
# Template configuration for focus nodes of type "http://www.w3.org/ns/locn#Address".
validator.reportItemAdditionalInfoTemplate.1.type = http://www.w3.org/ns/locn#Address
validator.reportItemAdditionalInfoTemplate.1.template = Country [${http://www.w3.org/ns/locn#adminUnitL1}]

Alongside such type-specific templates you may also include a general one to apply in case your focus node’s rdf:type does not match a specific case.

# Type-specific templates.
validator.reportItemAdditionalInfoTemplate.0.type = http://itb.ec.europa.eu/sample/po#Item
validator.reportItemAdditionalInfoTemplate.0.template = Product [${http://itb.ec.europa.eu/sample/po#productName}]
validator.reportItemAdditionalInfoTemplate.1.type = http://www.w3.org/ns/locn#Address
validator.reportItemAdditionalInfoTemplate.1.template = Country [${http://www.w3.org/ns/locn#adminUnitL1}]
# General template if no type-specific one applies.
validator.reportItemAdditionalInfoTemplate = Publisher [${http://purl.org/dc/terms/publisher}]

Finally, keep in mind that in case your validator supports multiple languages you may define all discussed configuration properties in your translation property files to have them correctly localised according to the user’s language preference.

Step 4: Setup validator as Docker container

Note

When to setup a Docker container: The purpose of setting up your validator as a Docker container is to host it yourself or run it locally on workstations. If you prefer or don’t mind the validator being accessible over the Internet it is simpler to delegate hosting to the test bed team by reusing the test bed’s infrastructure. If this is the case skip this section and go directly to Step 5: Setup validator on test bed. Note however that even if you opt for a validator managed by the test bed, it may still be interesting to create a Docker image for development purposes (e.g. to test new validation artefact versions) or to make available to your users as a complementary service (i.e. use online or download and run locally).

Once the validator’s configuration is ready (configuration file and validation artefacts) you can proceed to create a Docker image.

The configuration for your image is driven by means of a Dockerfile. Create this file in the validator folder with the following contents:

FROM isaitb/shacl-validator:latest
COPY resources /validator/resources/
ENV validator.resourceRoot /validator/resources/

This Dockerfile represents the most simple Docker configuration you can provide for the validator. Let’s analyse each line:

FROM isaitb/shacl-validator:latest

This tells Docker that your image will be built over the latest version of the test bed’s isaitb/shacl-validator image. This represents the validator’s core that expects configuration to drive the validation. It is available on the public Docker Hub and as such can be directly used through any Docker installation with Internet access.

COPY resources /validator/resources/

This copies your resources folder to the image under path /validator/resources/.

ENV validator.resourceRoot /validator/resources/

This instructs the validator that it should consider as the root of all its configuration resources the /validator/resources/ folder (which was just copied into it).

The contents of the validator folder should now be as follows:

validator
├── resources
│   └── order
│       ├── shapes
│       │   ├── PurchaseOrder-common-shapes.ttl
│       │   └── PurchaseOrder-large-shapes.ttl
│       └── config.properties
└── Dockerfile

That’s it. To build the Docker image open a command prompt to the validator folder and issue:

docker build -t po-validator .

This command will create a new local Docker image named po-validator based on the Dockerfile it finds in the current directory. It will proceed to download missing images (e.g. the isaitb/shacl-validator:latest image) and eventually print the following output:

Sending build context to Docker daemon  32.77kB
Step 1/3 : FROM isaitb/shacl-validator:latest
---> 39ccf8d64a50
Step 2/3 : COPY resources /validator/resources/
---> 66b718872b8e
Step 3/3 : ENV validator.resourceRoot /validator/resources/
---> Running in d80d38531e11
Removing intermediate container d80d38531e11
---> 175eebf4f59c
Successfully built 175eebf4f59c
Successfully tagged po-validator:latest

The new po-validator:latest image can now be pushed to a local Docker registry or to the Docker Hub. In our case we will proceed directly to run this as follows:

docker run -d --name po-validator -p 8080:8080 po-validator:latest

This command will create a new container named po-validator based on the po-validator:latest image you just built. It is set to run in the background (-d) and expose its internal listen port through the Docker machine (-p 8080:8080). Note that by default the listen port of the container (which you can map to any available host port) is 8080.

Your validator is now online and ready to validate RDF content. If you want to try it out immediately skip to Step 6: Use the validator. Otherwise, read on to see additional configuration options for the image.

Running without a custom Docker image

The discussed approach involved building a custom Docker image for your validator. Doing so allows you to run the validator yourself but also potentially push it to a public registry such as the Docker Hub. This would then allow anyone else to pull it and run a self-contained copy of your validator.

If such a use case is not important for you, or if you want to only use Docker for your local artefact development, you could also skip creating a custom image and use the base isaitb/shacl-validator image directly. To do so you would need to:

  • Define a named or unnamed Docker volume pointing to your configuration files.

  • Run your container by configuring it with the volume.

Considering the same file structure of the /validator folder you can launch your validator using an unnamed volume as follows:

docker run -d --name po-validator -p 8080:8080 \
           -v /validator/resources:/validator/resources/ \
           -e validator.resourceRoot=/validator/resources/  \
           isaitb/shacl-validator

As you see here we create the validator directly from the base image and pass it as a volume our resource root folder. When doing so you need to also make sure that the validator.resourceRoot environment variable is set to the path within the container.

Using this approach to run your validator has the drawback of being unable to share it as-is with other users. The benefit however is one of simplicity given that there is no need to build intermediate images. As such, updating the validator for configuration changes means that you only need to restart your container.

Configuring additional validation domains

Up to this point you have configured validation for purchase orders which defines one or more validation types (basic and large). This configuration can be extended by providing additional types to reflect:

  • Additional profiles with different business rules (e.g. minimal).

  • Specification versions (e.g. basic_v1.0, large_v1.0, basic_v1.1_beta).

  • Other types of content that are linked to purchase orders (e.g. purchase_order_basic_v1.0 and order_receipt_v1.0).

All such extensions would involve defining potentially additional validation artefacts and updating the config.properties file accordingly.

Apart from extending the validation possibilities linked to purchase orders you may want to configure a completely separate validator to address an unrelated specification that would most likely not be aimed to the same user community. To do so you have two options:

  • Repeat the previous steps to define a separate configuration and a separate Docker image. In this case you would be running two separate containers that are fully independent.

  • Reuse your existing validator instance to define a new validation domain. The result will be two validation services that are logically separate but are running as part of a single validator instance.

The rationale behind the second option is simply one of required resources. If you are part of an organisation that needs to support validation for dozens of different RDF-based specifications that are unrelated, it would probably be preferable to have a single application to host rather than one per specification.

Note

Sharing artefact files accross domains: Setting the application property validator.restrictResourcesToDomain to false allows to add paths of validation artefacts that are outside of the domain root folder. This enables sharing artefacts between different domains.

In your current single domain setup, the purchase order configuration is reflected through folder order. The name of this folder is also by default assumed to match the name of the domain. A new domain could be named invoice that is linked to RDF-based invoices. This is represented by an invoice folder next to order that contains similarly its validation artefacts and domain-level configuration property file. Considering this new domain, the contents of the validator folder would be as follows:

validator
├── resources
│   ├── invoice
│   │   └── (Further contents skipped)
│   └── order
│       └── (Further contents skipped)
└── Dockerfile

If you were now to rebuild the validator’s Docker image this would setup two logically-separate validation domains (invoice and order).

Note

Validation domains vs types: In almost all scenarios you should be able to address your validation needs by having a single validation domain with multiple validation types. Validation types under the same domain will all be presented as options for users. Splitting in domains would make sense if you don’t want the users of one domain to see the supported validation types of other domains.

Important: Support for such configuration is only possible if you are defining your own validator as a Docker image. If you plan to use the test bed’s shared validator instance (see Step 5: Setup validator on test bed), your configuration needs to be limited to a single domain. Note of course that if you need additional domains you can in this case simply repeat the configuration process multiple times.

Additional configuration options

We have seen up to now that configuring how validation takes place is achieved through domain-level configuration properties provided in the domain configuration file (file config.properties in our example). When setting up the validator as a Docker image you may also make use of application-level configuration properties to adapt the overall validator’s operation. Such configuration properties are provided as environment variables through ENV directives in the Dockerfile.

We already saw this when defining the validator.resourceRoot property that is the only mandatory property for which no default exists. Other such properties that you may choose to override are:

  • validator.domain: A comma-separated list of names that are to be loaded as the validator’s domains. By default the validator scans the provided validator.resourceRoot folder and selects as domains all subfolders that contain a configuration property file (folder order in our case). You may want to configure the list of folder names to consider if you want to ensure that other folders get ignored.

  • validator.domainName.DOMAIN: A mapping for a domain (replacing the DOMAIN placeholder) that defines the name that should be presented to users. This would be useful if the folder name itself (order in our example) is not appropriate (e.g. if the folder was named files).

The following example Dockerfile illustrates use of these properties. The values set correspond to the applied defaults so the resulting Docker images from this Dockerfile and the original one (see Step 4: Setup validator as Docker container) are in fact identical:

FROM isaitb/shacl-validator:latest
COPY resources /validator/resources/
ENV validator.resourceRoot /validator/resources/
ENV validator.domain order
ENV validator.domainName.order order

See Application-level configuration for the full list of supported application-level properties.

Finally, it may be the case that you need to adapt further configuration properties that relate to how the validator’s application is ran. The validator is built as a Spring Boot application which means that you can override all configuration properties by means of environment variables. This is rarely needed as you can achieve most important configuration through the way you run the Docker container (e.g. defining port mappings). Nonetheless the following adapted Dockerfile shows how you could ensure the validator’s application starts up on another port (9090) and uses a specific context path (/ctx).

FROM isaitb/shacl-validator:latest
COPY resources /validator/resources/
ENV validator.resourceRoot /validator/resources/
ENV server.servlet.context-path /ctx
ENV server.port 9090

Note

Custom port: Even if you define the server.port property to a different value other than the default 8080 this remains internal to the Docker container. The port through which you access the validator will be the one you map on your host through the -p flag of the docker run command.

The full list of such application configuration properties, as well as their default values, are listed in the Spring Boot configuration property documentation.

Environment-specific domain configuration

In the previous section you saw how could can configure the validator’s application by means of environment properties. Use of environment properties is also possible for specific validator domains, allowing you to externalise and override their configuration aspects. Typical cases where you may want to do this are:

  • To adapt the configuration for different instances of the same validator.

  • To hide sensitive properties such as internal URLs or passwords.

External configuration properties can be provided through environment variables or system properties (the latter being interesting when using a command line validator). These can contribute to the configuration:

  • Complete properties, by defining a variable or property with the same name as a configuration property.

  • Values, by referring to arbitrary variables or properties within a domain property file. This is done by defining a placeholder ${} and using within it the prefixes env: for environment variables or sys: for system properties (e.g. ${env:MY_VARIABLE}).

As a simple example of this, consider the definition of the title of the validator’s web UI. We want to adapt this title depending on the purpose of the specific validator instance. To begin with we can define the title via the validator.uploadTitle property in the config.properties file as follows:

validator.uploadTitle = Purchase Order Validator

The problem with this approach is that the upload title remains fixed across all instances of the validator. Alternatively we can define the value for the title as an environment variable named VALIDATOR_TITLE. To use this we can adapt config.properties to reference it as follows:

validator.uploadTitle = ${env:VALIDATOR_TITLE}

We can then adapt this for each Docker container we create by defining a specific value for the title:

docker run -e VALIDATOR_TITLE="Purchase Order Validator (Demo)" ...

A further alternative would be to externalise the complete validator.uploadTitle property by removing it from config.properties and specifying it as an environment variable:

docker run -e validator.uploadTitle="Purchase Order Validator (Demo)" ...

Note that such external configuration can also be used as a partial value. If we define an environment variable named VALIDATOR_ENV we could also use it within config.properties as follows:

validator.uploadTitle = Purchase Order Validator (${env:VALIDATOR_ENV})

Finally, you can use environment or system variables to override properties that are already defined in config.properties. This is useful if you use the file’s properties as default values and selectively override certain of them as needed. A property’s value is looked up in sequence as follows:

  1. Look in environment variables.

  2. If not found look in system properties.

  3. If not found look in the domain configuration file.

  4. If not found consider the property’s overall default value (see Domain-level configuration).

Step 5: Setup validator on test bed

Note

When to setup on test bed resources: Setting up your validator on the test bed’s resources removes hosting concerns and allows you to benefit from automatic service reloads for configuration changes. In doing so however you need to keep in mind that the validator will be exposed over the Internet. If this approach is not suitable for you (e.g. you want to expose the validator within a restricted network) you should consider setting up the validator as a Docker container (see Step 4: Setup validator as Docker container) that you can then host as you see fit.

To configure a validator using the test bed’s resources all you need to do is get in touch with the test bed team and provide the validator’s configuration. Specifically:

  1. Send an email to DIGIT-ITB@ec.europa.eu describing your case: This step is needed for two reasons. Firstly you may want to have a further discussion and potentially a demo to better understand the available options. Secondly the test bed’s team would need to ensure that you qualify to use its resources (to e.g. avoid that you are a private company planning to offer commercial validation services).

  2. Share the configuration for the validator: Once contact has been established you need to provide the initial configuration for the validator.

Regarding the second step, the validator’s configuration to be shared is the contents of the validator folder as described in Step 3: Prepare validator configuration. The eventual goal here will be to have the configuration available through an accessible Git repository. This can be done in a number of ways listed below in decreasing order of preference:

  • Create a new Git repository: You can push all resources (the validator folder) to a new Git repository (e.g. on GitHub or the European Commission’s CITNet Bitbucket server). You can of course add any other resources to this repository as you see fit (e.g. a README file). Once done provide the repository’s URL to the test bed team.

  • Provide the resources to the test bed team: You can send the configuration files themselves to the test bed’s team (e.g. make an archive of the validator folder). Ideally you should define the configuration file but if in doubt you can simply describe the resources and the test bed team will prepare the initial configuration for you. When following this approach a new Git repository will be created for you on the European Commission’s CITNet Bitbucket server for which you will be assigned write access (assuming you have a CITNet user account).

  • Update an existing Git repository: If you already have a Git repository to maintain the validation artefacts you can reuse this by adding to it the required configuration file (config.properties in our case). When ready you will need to provide the test bed team with the URL to the repository and the location of the configuration file.

Following the initial configuration, the resulting Git repository will be monitored to detect any changes to the validation artefacts or the configuration file. If such a change is detected, the validation service will be automatically updated within a few minutes.

Note

Using a dedicated Git repository for the validator: Whether you define a new Git repository yourself or the test bed team creates one for you, the result is a repository that is dedicated to the validator. This approach is preferable to reusing an existing Git repository to avoid unwanted changes to the validator. whether or not this is done through GitHub, CITNet’s Bitbucket or another service depends on what best suits your needs.

As part of the initial setup for the validator the test bed team will also configure how it is accessed. The name used will match the name of the folder that contains your configuration file (order in the considered example), but this can differ according to your preferences. If this is the case make sure to inform the test bed team of your preferred naming.

Considering our example, for a name of order, the resulting root URL through which the validator will be accessed is https://www.itb.ec.europa.eu/shacl/order. The specific paths will depend on the supported validation channels as described in Step 6: Use the validator.

Offline validator for command-line use

Each validator set up on test bed resources is also made available as a command-line tool that can be downloaded and used in a standalone manner. This command-line tool is a Java-based application packaged as an “all-in-one” executable JAR file. For each supported DOMAIN the command-line validator is published at:

https://www.itb.ec.europa.eu/shacl-offline/DOMAIN/validator.zip

It is important to note that no additional configuration is needed to create such command-line tools. In addition, any changes in the validator’s configuration will result in its command-line tool being updated automatically.

Check section Validation via command-line tool for instructions on how to use it.

Step 6: Use the validator

Well done! At this step your validator has been successfully configured and is ready to use. Depending on which approach was followed, this may have been done either:

The validation channels that are supported depend on the configuration you have supplied. This is done through the validator.channels property of your configuration file (config.properties) that defaults to form, rest_api, soap_api. The supported channels are as follows:

  • form: A web user interface allowing a user to provide the RDF content to validate.

  • rest_api: A REST API allowing machine-to-machine integration using HTTP calls.

  • soap_api: A SOAP API allowing contract-based machine-to-machine integration using SOAP web service calls.

The following sub-sections describe how each channel can be used considering the example EU purchase order specification.

Validation via user interface

The validator’s user interface is available at the /shacl/DOMAIN/upload path. The exact path depends on how this is deployed:

The first page that you see is a simple form to provide the RDF content to validate.

../_images/validator_upload2.png

This form expects the following input:

  • Content to validate: The RDF content that will be submitted for validation. The preceding dropdown selection determines how this will be provided, specifically as a file input (pre-selected), as a URI to be loaded remotely or as content to be provided using an editor. In case you have enabled SPARQL queries you will also see here the option to provide input via SPARQL query.

  • Validate as: The type of validation to apply.

  • Content syntax: The syntax to consider for the provided content. This may be omitted in case of file upload or URI input if the file’s extension can determine the syntax. Note that this is hidden in case you provide input via SPARQL query.

The dropdown menu to the right of the Content to validate label selects the input method. For this you have four choices:

  • File: Content provided as a file upload (the default).

  • URI: Content provided as a remote URI reference.

  • Direct input: Content encoded directly in an on-screen editor.

  • Query: Content queried from a SPARQL endpoint (if enabled - see Configuring SPARQL query support).

In case the validator is configured to support multiple languages, the form includes an additional dropdown menu to list them in the bottom-right corner. Selecting one of these languages will reload the interface and will record your choice to apply it automatically for future visits.

../_images/validator_upload_languages2.png

Note that all displayed labels can be adapted through the config.properties configuration file (see Properties related to UI labels). The available validation types match the ones defined in the validator.type property, displayed using the validator.typeLabel.TYPE labels. Moreover, the text title could be replaced by a configurable HTML banner, and further complemented with a HTML footer (see Domain-level configuration).

../_images/validator_upload_selected2.png

It is worth noting also that if your configuration defined only a single validation type, the user interface would be simplified by presenting only the content input controls (i.e. considering the single validation type as pre-selected).

../_images/validator_upload_simple2.png

In addition, if your configuration for the selected validation type allows for user-provided SHACL shapes, the form also includes the controls to manage the shape files you provide. Files can be defined via file upload or remote URI, specifying at the same time the syntax to consider if this cannot be determined by its extension (similar to the content to validate).

../_images/validator_upload_external2.png

Finally, if you also specified in your configuration that the user should choose whether imports are to be loaded when forming the data graph to validate, this will also be reflected in the user interface.

../_images/validator_upload_imports.png

Once you have provided your input click the Validate button to trigger the validation. Upon completion you will be presented with the validation results:

../_images/validator_result2.png

This screen includes an overview of the result listing:

  • The validation timestamp (in UTC), the name of the validated file and the applied validation type (if more than one are configured).

  • The overall result (SUCCESS or FAILURE).

  • The number of errors, warnings and information messages.

This section is followed by the Details panel, where the details of each report item are listed:

  • It’s type (whether this is an error, warning or information message).

  • It’s description.

  • It’s location in the provided input in terms of the focus node and its specific path.

  • The test performed in terms of the name of the SHACL rule applied and the value that was tested.

With respect to reporting, apart from the on-screen display, you are also presented with download buttons to:

  • Download the validation report in PDF (selected by default - sample here) or CSV format. You may also select to download the report as a SHACL Validation Report in any of the provided syntaxes (sample in Turtle here).

  • Download the SHACL shapes used for the validation in any of the provided syntaxes. Note that the shapes in this case will be the aggregated shapes from predefined files and user-provided ones (if supported and provided).

  • Download the validated content in any of the provided syntaxes.

In case validation has produced similar findings for multiple focus nodes, the validator offers the possibility to view reports in detailed (the default) or aggregated format. In case of an aggregated report, findings that have the same description, shape and severity are merged to display only the first one, alongside an indication of the total number of occurrences. This indication is added as a prefix to the displayed description.

../_images/validator_result_aggregated2.png

Aggregated reports are also available to download in PDF or CSV formats. Regarding the on-screen display of findings, this can be switched between detailed and aggregated by using the provided control on the top of the “Details” panel. In case the validation report, detailed or aggregate, includes findings at different severity levels, you may also filter the displayed on-screen findings to show all items (the default), or show specifically errors, warnings and information messages.

Finally, once a validation result is produced you may trigger additional validations. To do this you may either use the form from the top of the result screen or click on the form’s title to take you back to the previous page.

Validation via minimal user interface

If you are exposing a web user interface (see Validation via user interface) for your validator you also have the option of enabling an alternative minimal interface that could be used as an embedded component in another web page (e.g. via an iframe). This is enabled through the validator.supportMinimalUserInterface property in your domain configuration (file config.properties).

...
validator.supportMinimalUserInterface = true

The result of this is to expose a /shacl/DOMAIN/uploadm path. The path depends on how this is deployed:

The minimal interface offers largely the same functionality as the complete one but with a more condensed layout and minimal styling. The initial input page you see for the validator is as follows:

../_images/validator_upload_minimal2.png

The most significant difference is the result page which provides initially only the overview and the relevant download controls:

../_images/validator_result_minimal2.png

You can switch to display the detailed findings by clicking the View details button in which case you will also see the relevant findings’ filtering controls. All controls and displayed information for the input as well as the summary and detailed result pages are identical to the complete user interface (see Validation via user interface).

Validation via embedded interface

In case you want to use the validator through an existing web application the typical approach would be to use the validator’s machine-to-machine interface (via REST API or SOAP API). This allows you to present your own user interface to users while integrating with the validator in the background to validate provided data.

An alternative to this integration is to embed the validator’s user interface directly within your own user interface. This is possible for web applications but also for simple websites that would collect input data and provide it to the validator. When embedding the validator in this way you define an iframe in your interface’s HTML and set its source to point to the validator. Doing as such, results in the validator’s user interface displayed within your own, placed inside the defined iframe.

When embedding the validator in this way you have the following options available:

  • You may embed the validator’s complete user interface as-is. To do this set the source of the iframe to the validator’s interface (e.g. https://www.itb.ec.europa.eu/shacl/order/upload).

  • Alternatively you may embed the validator’s minimal user interface (if enabled) for a more concise presentation. To do this set the source of the iframe to the validator’s minimal interface variant (/uploadm instead of /upload).

  • If you want to manage data input yourself you may skip the validator’s input form, using it only to display validation results. In this case you would typically use the validator’s minimal user interface as its result display does not include an input form.

If you are using the validator only to display results (i.e. the last option above), you will need to manage data input yourself and provide it to the validator as it expects. To do this you include your inputs in a form that will need to be submitted to the validator via a HTTP POST request. The request parameters you may provide are listed in the following table:

Input name

Input type

Description

Required?

file

file

The file to validate. If provided the form must be a set as multipart/form-data.

One of file, uri or text must be provided.

uri

text

The URI from which to load the content to validate.

One of file, uri or text must be provided.

text

text

The text to validate.

One of file, uri or text must be provided.

contentType

text

The type of input to consider (use fileType for file, uriType for uri or stringType for text).

Skip if only one of file, uri or text is submitted.

contentSyntaxType

text

The RDF syntax type of the content (provided as a mime type - e.g. application/rdf+xml).

Required for text, and for file or uri if no known file extension can be detected.

validationType

text

The type of validation to perform (as defined in the validator’s configuration).

Required unless the validator only defines a single validation type.

The following HTML sample is a simple web page that provides a file input control for its users:

<html>
    <head><title>Simple validator</title></head>
    <body>
        <h1>Validate your data</h1>
        <form method="POST" enctype="multipart/form-data" action="https://www.itb.ec.europa.eu/shacl/order/uploadm" target="output">
            <input type="file" name="file">
            <input type="hidden" name="validationType" value="large">
            <button type="submit">Validate</button>
        </form>
        <iframe name="output" style="width:100%; height:50%;" src='about:blank'></iframe>
    </body>
</html>

In the above sample take note of the following points:

  • Our input control is a file upload whereas the validation type is fixed and hidden. As we have a file upload, the enclosing form is set to make a multipart submission.

  • The validator interface to be used to display the results is the minimal interface (identified by the /uploadm path).

  • The validation result is displayed in an iframe named output. This is set to be initially empty.

  • The validation submission, a HTTP POST, is set to target the iframe. Once the validation is complete the iframe will display the output.

The following screenshot shows how the above configuration would appear once a validation has taken place.

../_images/validator_embedded2.png

Note

Disable validator embedding: For the validator to be embedded it needs to allow itself to be presented in iframes. If you prefer to disable this feature (see why here) you may set property validator.supportUserInterfaceEmbedding to false.

Validation via REST web service API

The validator’s REST API is available under the /shacl/DOMAIN/api path. The exact path depends on how this is deployed:

The operations that the REST API supports are the following:

Operation

Description

HTTP method

Request payload type

info

Retrieve the available validation types for a given domain (or for all domains).

GET

None

validate

Validate one RDF instance.

POST

application/json

validateMultiple

Validate multiple RDF instances.

POST

application/json

The supported operations as well their input and output are thoroughly documented:

  • Using OpenAPI and Swagger, with the documentation available at the /shacl/swagger-ui/ path.

  • Using Hydra where the API entry point is available at the /shacl/DOMAIN/api path.

The Swagger UI is notable as this provides rich, interactive documentation that can also be used to call the underlying operations. To access this navigate to:

../_images/swagger_ui2.png

Note that before using the Swagger UI to execute any of the operations you will also need to specify the {domain} path parameter. In the example we have been following this would be order.

Coming back to the specific operations supported, the first one to address is the info operation. This can be useful if the validator is configured with multiple validation types in which case this service returns each type’s name and description.

Considering our order example making a GET request to http://DOCKER_MACHINE:8080/shacl/order/api/info (or https://www.itb.ec.europa.eu/shacl/order/api/info on the test bed), you receive a JSON response as follows:

{
    "domain": "order",
    "validationTypes": [
        {
            "type": "basic",
            "description": "Basic purchase order"
        },
        {
            "type": "large",
            "description": "Large purchase order"
        }
    ]
}

Note

In case your validator supports multiple domains, you may obtain their complete listing (domains and validation types per domain), by omitting the {domain} path parameter.

To trigger validation of a RDF instance you use the validate operation by making a POST request of type application/json to http://DOCKER_MACHINE:8080/shacl/order/api/validate (or https://www.itb.ec.europa.eu/shacl/order/api/validate on the test bed). The payload of the validate operation defines the following properties:

Property

Description

Required?

Type

Default value

contentToValidate

The content to validate.

Yes (optional if queries are supported)

A string that is interpreted based on the embeddingMethod input.

contentSyntax

The syntax of the provided content.

Yes, unless the content is provided as a file, or URI for a file with a well-known extension.

A mime type string (e.g. application/ld+json, application/rdf+xml, text/turtle, application/n-triples).

embeddingMethod

The way in which to interpret the contentToValidate value. It is advised to always provide this for best performance. If not provided the validator will attempt to infer the method from the content.

No

One of STRING (for content provided directly), BASE64 (for content embedded as a BASE64 encoded string) or URL (for a reference to remote content).

validationType

The type of validation to perform.

Yes, unless a single validation type is defined.

String

The single configured validation type (if defined).

contentQuery

A SPARQL CONSTRUCT query to be used to get the content to validate.

No

String

contentQueryEndpoint

The SPARQL endpoint URL to query (if not preconfigured).

No

String

contentQueryUsername

The username to use for SPARQL endpoint authentication (if not preconfigured).

No

String

contentQueryPassword

The password to use for SPARQL endpoint authentication (if not preconfigured).

No

String

externalRules

An array of user-provided SHACL shape extensions to be considered with any predefined ones. These are accepted only if explicitly allowed in the configuration for the validation type in question.

No

An array of RuleSet entries (see below for content).

loadImports

The choice of whether or not imports are to be loaded when forming the data graph to validate.

No

Boolean

false

reportSyntax

The mime type for the validation report syntax. Providing an RDF mime type (application/ld+json, application/rdf+xml, text/turtle, application/n-triples) will produce a SHACL validation report. Specifying application/xml, text/xml or application/json will produce the report in the GITB TRL syntax (in XML or JSON). If no syntax is provided application/rdf+xml is considered as the default, unless a different syntax is configured for the domain in question.

No

String

The default configured for the validator (application/rdf+xml if not overriden).

reportQuery

A SPARQL CONSTRUCT query that will be executed on the resulting SHACL validation report as a post-processing step. If provided, the result of this query will replace the SHACL validation report in the service’s output.

No

String

locale

Locale (language code) to use for reporting of results. If the provided locale is not supported by the validator the default locale will be used instead (e.g. “fr”, “fr_FR”). See Supporting multiple languages for details.

No

String

addInputToReport

In case a GITB TRL report is requested (see reportSyntax), whether to include the validated input in the resulting report’s context section. If returning a SHACL validation report this input is ignored.

No

Boolean

false

addShapesToReport

In case a GITB TRL report is requested (see reportSyntax), whether to include the SHACL shapes in the resulting report’s context section. If returning a SHACL validation report this input is ignored.

No

Boolean

false

addRdfReportToReport

In case a GITB TRL report is requested (see reportSyntax), whether to include the SHACL validation report in the resulting GITB TRL report’s context section. If returning a SHACL validation report this input is ignored.

No

Boolean

false

rdfReportSyntax

In case a GITB TRL report is requested (see reportSyntax), and the SHACL validation report is set to be included in GITB TRL report’s context section, this is the mime type to use for the SHACL validation report. If returning a SHACL validation report this input is ignored.

No

String

The default configured for the validator (application/rdf+xml if not overriden).

wrapReportDataInCDATA

Whether to wrap the data added to the report (see addInputToReport, addShapesToReport and addRdfReportToReport) in CDATA blocks if producing it in the XML GITB TRL format. False results in adding data via XML escaping.

No

Boolean

false

In case user-provided SHACL shapes are supported, these are provided as RuleSet entries as elements of the externalRules array. The content of each RuleSet is as follows:

Property

Description

Required?

Type

Default value

ruleSet

The RDF containing the rules to apply (shapes).

Yes

A string that is interpreted based on the embeddingMethod input.

embeddingMethod

The way in which to interpret the value for ruleSet. It is advised to always provide this for best performance. If not provided the validator will attempt to infer the method from the ruleSet value.

No

One of STRING (for content provided directly), BASE64 (for content embedded as a BASE64 encoded string) or URL (for a reference to remote content).

ruleSyntax

The syntax of the provided ruleSet.

Yes, unless the content is provided as a file, or URI for a file with a well-known extension.

A mime type string (e.g. application/ld+json, application/rdf+xml, text/turtle, application/n-triples).

To illustrate how this operation can be used we will consider a purchase order that will fail validation when checked to be of large type due to it lacking the required quantities per item (you can download the sample here):

@prefix ns0: <http://www.w3.org/ns/locn#> .
@prefix ns1: <http://itb.ec.europa.eu/sample/po#> .

<http://my.sample.po/po#purchaseOrder>
  a <http://itb.ec.europa.eu/sample/po#PurchaseOrder> ;
  ns1:shipTo <http://my.sample.po/po#home> ;
  ns1:billTo <http://my.sample.po/po#home> ;
  ns1:hasItem <http://my.sample.po/po#item1>;
  ns1:hasItem  <http://my.sample.po/po#item2> .

<http://my.sample.po/po#home>
  a <http://www.w3.org/ns/locn#Address> ;
  ns0:fullAddress "Rue du Test 123, 1000 - Brussels, Belgium" ;
  ns0:thoroughfare "Rue du Test" ;
  ns0:locatorDesignator "123" ;
  ns0:postCode "1000" ;
  ns0:postName "Brussels" ;
  ns0:adminUnitL1 "BE" .

<http://my.sample.po/po#item1>
  a ns1:Item ;
  ns1:productName "Mouse" ;
  ns1:quantity 5 ;
  ns1:priceEUR 15.99 .

<http://my.sample.po/po#item2>
  a ns1:Item ;
  ns1:productName "Keyboard" ;
  ns1:quantity 15 ;
  ns1:priceEUR 25.50 .

As a first validation example we will provide the content to validate as a URI to be looked up:

{
    "contentToValidate": "https://www.itb.ec.europa.eu/files/samples/shacl/sample-invalid.ttl",
    "validationType": "large"
}

In the contentToValidate parameter we include the URI to the file whereas in the validationType parameter we select the desired validation type. Note that we need to define the validation type as we have more than one configured for purchase orders. If there was only one this parameter would be optional.

The response returned for this call will be the SHACL validation report in application/rdf+xml syntax:

<rdf:RDF
    xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
    xmlns:po="http://itb.ec.europa.eu/sample/po#"
    xmlns:locn="http://www.w3.org/ns/locn#"
    xmlns:sh="http://www.w3.org/ns/shacl#"
    xmlns:xsd="http://www.w3.org/2001/XMLSchema#">
    <sh:ValidationReport>
        <sh:conforms rdf:datatype="http://www.w3.org/2001/XMLSchema#boolean">false</sh:conforms>
        <sh:result>
            <sh:ValidationResult>
                <sh:value rdf:datatype="http://www.w3.org/2001/XMLSchema#integer">3</sh:value>
                <sh:resultPath rdf:resource="http://itb.ec.europa.eu/sample/po#quantity"/>
                <sh:resultMessage>Value is not &gt; 10^^http://www.w3.org/2001/XMLSchema#integer</sh:resultMessage>
                <sh:focusNode rdf:resource="http://my.sample.po/po#item2"/>
                <sh:sourceShape rdf:resource="http://itb.ec.europa.eu/sample/po#minimumItemsForLargeOrderShape"/>
                <sh:sourceConstraintComponent rdf:resource="http://www.w3.org/ns/shacl#MinExclusiveConstraintComponent"/>
                <sh:resultSeverity rdf:resource="http://www.w3.org/ns/shacl#Violation"/>
            </sh:ValidationResult>
        </sh:result>
    </sh:ValidationReport>
</rdf:RDF>

In this report we can see the overall validation result (false in sh:conforms), as well as the individual report items (one in this case). Each such item includes:

  • The severity of the item (sh:resultSeverity).

  • The message for the item (sh:resultMessage).

  • The location in the validated content that triggered the failure (sh:focusNode and sh:resultPath).

  • The test that was made (the failing shape sh:sourceShape, the constraint type sh:sourceConstraintComponent and the tested value sh:value).

You may request the validation report in different syntaxes by providing as part of the input the reportSyntax property with the desired report mime type. For example, to request the report in Turtle format you would provide:

{
    "contentToValidate": "https://www.itb.ec.europa.eu/files/samples/shacl/sample-invalid.ttl",
    "validationType": "large",
    "reportSyntax": "text/turtle"
}

Resulting in the same report but this time in Turtle syntax:

@prefix sh:    <http://www.w3.org/ns/shacl#> .
@prefix xsd:   <http://www.w3.org/2001/XMLSchema#> .
@prefix locn:  <http://www.w3.org/ns/locn#> .
@prefix po:    <http://itb.ec.europa.eu/sample/po#> .

[ a            sh:ValidationReport ;
sh:conforms  false ;
sh:result    [ a                             sh:ValidationResult ;
                sh:focusNode                  <http://my.sample.po/po#item2> ;
                sh:resultMessage              "Value is not > 10^^http://www.w3.org/2001/XMLSchema#integer" ;
                sh:resultPath                 po:quantity ;
                sh:resultSeverity             sh:Violation ;
                sh:sourceConstraintComponent  sh:MinExclusiveConstraintComponent ;
                sh:sourceShape                po:minimumItemsForLargeOrderShape ;
                sh:value                      3
            ]
] .

This could also have been achieved by means of an HTTP Accept header sent with the POST request with a value of text/turtle.

Note

Default report syntax: The validation report is returned by default in application/rdf+xml syntax. You may override this as part of your domain configuration (in file config.properties) by setting the validator.defaultReportSyntax property to the desired mime type.

An alternative to producing a SHACL validation report is to return the validation result expressed in the GITB Test Reporting Language (TRL), a generic format available in XML and JSON representations, supported by all types of validators. To obtain such a report you use the same reportSyntax input (or HTTP Accept header) with values:

  • application/xml or text/xml for an XML GITB TRL report.

  • application/json for a JSON GITB TRL report.

The GITB TRL report format supports also context information concerning the validation. In the case of the RDF validator you may use the following inputs to include context information as follows:

  • addInputToReport, to include the validated input.

  • addShapesToReport, to include the aggregated shapes that were used for the validation.

  • addRdfReportToReport, to include the underlying RDF SHACL validation report. In this case you can adapt the RDF syntax used for the SHACL validation report using the additional input rdfReportSyntax which is set with the desired report’s mime type.

Note

CDATA vs XML-escaping: By default context data is added to the XML GITB TRL report using XML escaping. If you would prefer that CDATA blocks are used instead you may specify wrapReportDataInCDATA as true.

To illustrate the above, repeating the earlier validation calls to produce GITB TRL reports, we can extract the report in XML using the following inputs:

{
    "contentToValidate": "https://www.itb.ec.europa.eu/files/samples/shacl/sample-invalid.ttl",
    "validationType": "large",
    "reportSyntax": "application/xml"
}

This results in an XML GITB TRL report as follows:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<TestStepReport xmlns="http://www.gitb.com/tr/v1/" xmlns:ns2="http://www.gitb.com/core/v1/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" name="SHACL Validation" xsi:type="TAR">
    <date>2022-11-10T16:33:45.739+01:00</date>
    <result>FAILURE</result>
    <counters>
        <nrOfAssertions>0</nrOfAssertions>
        <nrOfErrors>1</nrOfErrors>
        <nrOfWarnings>0</nrOfWarnings>
    </counters>
    <context/>
    <reports>
        <error xsi:type="BAR">
            <description>You need to specify more items for large orders</description>
            <location>[Focus node] - [http://my.sample.po/po#item2] - [Result path] - [http://itb.ec.europa.eu/sample/po#quantity]</location>
            <test>[Shape] - [http://itb.ec.europa.eu/sample/po#minimumItemsForLargeOrderShape] - [Value] - [3]</test>
        </error>
    </reports>
</TestStepReport>

In case you would want to display the XML GITB TRL report in a user-friendly manner, the test bed makes available XSL stylesheets to transform it to HTML. This provides an alternative to using the validator’s user interface, when you need to work with a REST API but still want to present the resulting report as-is. Stylesheets for all official EU languages are available in a ZIP bundle, whereas individual stylesheets per language can also be accessed directly using the following URL (replace LANGUAGE with your desired language’s two-letter ISO code):

https://www.itb.ec.europa.eu/files/stylesheets/gitb_trl/gitb_trl_stylesheet_v1.0.LANGUAGE.xsl.

For a similar report in JSON format, use the following inputs:

{
    "contentToValidate": "https://www.itb.ec.europa.eu/files/samples/shacl/sample-invalid.ttl",
    "validationType": "large",
    "reportSyntax": "application/json"
}

This call results in the GITB TRL report expressed in JSON:

{
    "date": "2022-11-10T17:27:50.086+0100",
    "result": "FAILURE",
    "counters": {
        "nrOfAssertions": 0,
        "nrOfErrors": 1,
        "nrOfWarnings": 0
    },
    "context": {},
    "reports": {
        "error": [
            {
                "description": "You need to specify more items for large orders",
                "location": "[Focus node] - [http://my.sample.po/po#item2] - [Result path] - [http://itb.ec.europa.eu/sample/po#quantity]",
                "test": "[Shape] - [http://itb.ec.europa.eu/sample/po#minimumItemsForLargeOrderShape] - [Value] - [3]"
            }
        ]
    },
    "name": "SHACL Validation"
}

In the previous examples we saw validation by passing a reference to a remote resource as a URI. You may also choose to embed the content to be validated within the request itself as a BASE64 encoded string. To do so you set the value of the contentToValidate property to the BASE64 string but also specify the contentSyntax property with the input’s mime type (text/turtle in our case) as this can no longer be determined from the content’s file extension:

{
    "contentToValidate": "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",
    "contentSyntax": "text/turtle",
    "validationType": "large"
}

The contentSyntax property can also be provided when the input is a URI although this can be skipped if it can be determined from the referenced file’s extension. Note that in terms of the content to validate you may also specify the embeddingMethod property with a value of either STRING, URL or BASE64. The purpose of this is to explicitly define how the contentToValidate value should be interpreted. If not specified, the content will be checked to determine the method. The following example defines the embeddingMethod property and is equivalent to the previous one:

{
    "contentToValidate": "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",
    "embeddingMethod": "BASE64",
    "contentSyntax": "text/turtle",
    "validationType": "large"
}

In case SPARQL queries are supported, the contentToValidate input property becomes optional, given that you can provide input via query. To do this use property contentQuery instead. In case the validator setup expects you to provide credentials or the SPARQL endpoint itself, this is done via the contentQueryUsername, contentQueryPassword and contentQueryEndpoint properties. Taking as an example a case where the user is expected to provide only the query, the request would be as follows:

{
    "contentQuery": "CONSTRUCT { ?s ?p ?o } WHERE { GRAPH <urn:sparql:tests:uri> { ?s ?p ?o } . }",
    "validationType": "large"
}

To define whether imports are to be loaded when forming the data graph to validate, you would provide the loadImports property with a Boolean value (true or false). An example is provided below:

{
    "contentToValidate": "https://www.itb.ec.europa.eu/files/samples/shacl/sample-invalid.ttl",
    "validationType": "large",
    "reportSyntax": "text/turtle",
    "loadImports": true
}

Finally, recall that in Step 3: Prepare validator configuration the possibility was mentioned to allow for a given validation type, external SHACL shapes to be provided as part of the validator’s input. To do this through the REST API you provide the externalRules array containing objects with three properties:

  • ruleSet for the RDF content containing the SHACL shapes to consider.

  • ruleSyntax for the syntax of the ruleSet RDF content.

  • embeddingMethod (STRING, URL or BASE64) to determine how the ruleSet value is to be considered.

Similar to the input content, the ruleSyntax can be skipped if the ruleSet value is a URL for a file with a known file extension. Also the embeddingMethod can be skipped to allow the validator to determine it itself, although it is best to define this to improve performance.

A sample request specifying an additional set of SHACL shapes is provided below:

{
    "contentToValidate": "https://www.itb.ec.europa.eu/files/samples/shacl/sample-invalid.ttl",
    "validationType": "large",
    "reportSyntax": "text/turtle",
    "externalRules": [
        {
            "ruleSet": "https://path.to.file/shape_extensions.ttl"
        }
    ]
}

Note

Blocking user-provided extensions and choice to load imports: If you provide SHACL shape extensions or choose to load imports for a validation type where this has not been explicitly allowed the call will fail.

The remaining operation that is available is validateMultiple that can be used for batch validation. In this case the input to the service uses the same JSON structure but this time as an array. To use the operation submit a POST request of type application/json to http://DOCKER_MACHINE:8080/shacl/order/api/validateMultiple (or https://www.itb.ec.europa.eu/shacl/order/api/validateMultiple on the test bed).

In the following example two distinct validations are requested:

[
    {
        "contentToValidate": "https://www.itb.ec.europa.eu/files/samples/shacl/sample.ttl",
        "validationType": "basic",
        "reportSyntax": "text/turtle"
    },
    {
        "contentToValidate": "https://www.itb.ec.europa.eu/files/samples/shacl/sample-invalid.ttl",
        "validationType": "large",
        "reportSyntax": "text/turtle"
    }
]

The resulting response in this case always includes the reports as BASE64 encoded strings, specifying the syntax to consider:

[
    {
        "report": "QHB...Lgo=",
        "reportSyntax": "text/turtle"
    },
    {
        "report": "QHB...C4K",
        "reportSyntax": "text/turtle"
    }
]

Validation via SOAP web service API

The validator’s SOAP API is available under the /shacl/soap path. The exact path depends on how this is deployed (path to WSDL provided):

The SOAP API used is the GITB validation service API, meaning that the validator is a GITB-compliant validation service. The importance of this is that apart from using it directly, this SOAP API allows integration of the validator in more complex conformance testing scenarios as a validation step in GITB TDL test cases. This potential is covered further in Step 7: Use the validator in GITB TDL test cases.

The operations supported are as follows:

  • getModuleDefinition: Called to return information on how to call the service (i.e. what inputs are expected).

  • validate: Called to trigger validation for provided content.

You can download this SOAP UI project that includes sample calls of these operations (make sure to change the service URL to match your setup).

Regarding the getModuleDefinition operation, a request of:

<?xml version="1.0" encoding="UTF-8"?>
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:v1="http://www.gitb.com/vs/v1/">
   <soapenv:Header/>
   <soapenv:Body>
      <v1:GetModuleDefinitionRequest/>
   </soapenv:Body>
</soapenv:Envelope>

Will produce a response as follows:

<?xml version="1.0" encoding="UTF-8"?>
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
   <soap:Body>
      <ns4:GetModuleDefinitionResponse xmlns:ns2="http://www.gitb.com/core/v1/" xmlns:ns3="http://www.gitb.com/tr/v1/" xmlns:ns4="http://www.gitb.com/vs/v1/">
         <module operation="V" id="ValidatorService">
            <ns2:metadata>
               <ns2:name>ValidatorService</ns2:name>
               <ns2:version>1.0.0</ns2:version>
            </ns2:metadata>
            <ns2:inputs>
               <ns2:param type="binary" name="contentToValidate" use="R" kind="SIMPLE" desc="The content to validate, provided as a string, BASE64 or a URI."/>
               <ns2:param type="string" name="embeddingMethod" use="O" kind="SIMPLE" desc="The embedding method to consider for the 'contentToValidate' input ('BASE64', 'URL' or 'STRING')."/>
               <ns2:param type="string" name="contentSyntax" use="O" kind="SIMPLE" desc="The mime type of the provided content."/>
               <ns2:param type="string" name="validationType" use="O" kind="SIMPLE" desc="The type of validation to perform (if multiple types are supported)."/>
               <ns2:param type="list[map]" name="externalRules" use="O" kind="SIMPLE" desc="A list of maps that defines external SHACL shapes to consider in addition to any preconfigured ones. Each map item corresponds to a SHACL file and defines the following keys: 'ruleSet' (the rules to consider, see 'contentToValidate' for its semantics), 'ruleSyntax' (the syntax of the 'ruleSet' content, see 'contentSyntax' for its semantics), 'embeddingMethod' (the way to consider the 'ruleSet' value)."/>
            </ns2:inputs>
         </module>
      </ns4:GetModuleDefinitionResponse>
   </soap:Body>
</soap:Envelope>

This response can be customised through configuration properties in config.properties to provide descriptions specific to your setup. For example, extending config.properties with the following:

...
validator.webServiceId = PurchaseOrderValidator
validator.webServiceDescription.contentToValidate = The purchase order content to validate
validator.webServiceDescription.contentSyntax = The syntax (mime type) of the purchase order
validator.webServiceDescription.validationType = The type of validation to perform ('basic' or 'large')
validator.webServiceDescription.externalRules = Skip this as externally provided SHACL shapes are not supported

Will produce a response as follows:

<?xml version="1.0" encoding="UTF-8"?>
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
   <soap:Body>
      <ns4:GetModuleDefinitionResponse xmlns:ns2="http://www.gitb.com/core/v1/" xmlns:ns3="http://www.gitb.com/tr/v1/" xmlns:ns4="http://www.gitb.com/vs/v1/">
         <module operation="V" id="PurchaseOrderValidator">
            <ns2:metadata>
               <ns2:name>PurchaseOrderValidator</ns2:name>
               <ns2:version>1.0.0</ns2:version>
            </ns2:metadata>
            <ns2:inputs>
               <ns2:param type="binary" name="contentToValidate" use="R" kind="SIMPLE" desc="The purchase order content to validate"/>
               <ns2:param type="string" name="embeddingMethod" use="O" kind="SIMPLE" desc="The embedding method to consider for the 'contentToValidate' input ('BASE64', 'URL' or 'STRING')."/>
               <ns2:param type="string" name="contentSyntax" use="O" kind="SIMPLE" desc="The syntax (mime type) of the purchase order"/>
               <ns2:param type="string" name="validationType" use="O" kind="SIMPLE" desc="The type of validation to perform ('basic' or 'large')"/>
               <ns2:param type="list[map]" name="externalRules" use="O" kind="SIMPLE" desc="Skip this as externally provided SHACL shapes are not supported"/>
            </ns2:inputs>
         </module>
      </ns4:GetModuleDefinitionResponse>
   </soap:Body>
</soap:Envelope>

Running the validation itself is done through the validate operation. This expects the following inputs:

Input

Description

Required?

Type

Default value

contentToValidate

The content to validate.

Yes (optional if queries are supported)

A string that is interpreted based on the embeddingMethod input.

embeddingMethod

The way in which to interpret the contentToValidate value.

Yes, but should be skipped in favour of the embeddingMethod attribute - see below.

One of BASE64 (for content embedded as a BASE64 encoded string), URI (for a reference to remote content) or STRING (for content embedded as-is).

contentSyntax

The syntax of the provided content.

Yes, unless the content is provided as a URI for a file with a well-known extension.

A mime type string (e.g. text/turtle).

contentQuery

A SPARQL CONSTRUCT query to be used to get the content to validate.

No

String

contentQueryEndpoint

The SPARQL endpoint URL to query (if not preconfigured).

No

String

contentQueryUsername

The username to use for SPARQL endpoint authentication (if not preconfigured).

No

String

contentQueryPassword

The password to use for SPARQL endpoint authentication (if not preconfigured).

No

String

validationType

The type of validation to perform.

Yes, unless a single validation type is defined.

String

The single configured validation type (if defined).

externalRules

A list of user-provided SHACL shape extensions to be considered with any predefined ones. These are accepted only if explicitly allowed in the configuration for the validation type in question.

No

A list of map entries (see below for content).

loadImports

The choice of whether or not imports are to be loaded when forming the data graph to validate.

No

Boolean

false

reportSyntax

The syntax (provided as a mime type) for the resulting report (can be skipped for the default syntax).

No

A mime type string (e.g. text/turtle).

The default configured for the validator (application/rdf+xml if not overriden).

addInputToReport

Whether or not the output report should include as context the validated input.

No

Boolean

false

addRulesToReport

Whether or not the output report should include as context the SHACL shapes used for validation.

No

Boolean

false

addRdfReportToReport

Whether or not the raw RDF report should be returned as part of the resulting context information.

No

Boolean

false

rdfReportSyntax

The mime type for the raw RDF report returned as part of the resulting context (if included).

No

A mime type string (e.g. text/turtle).

The default configured for the validator (application/rdf+xml if not overriden).

rdfReportQuery

A post-processing SPARQL CONSTRUCT query to run on the RDF report before returning it in the resulting context. This is considered only if addRdfReportToReport is set to true.

No

String

locale

Locale (language code) to use for reporting of results. If the provided locale is not supported by the validator the default locale will be used instead (e.g. “fr”, “fr_FR”). See Supporting multiple languages for details.

No

String

Regarding the externalRules, this is a list of one of more entries. For each such entry the following input properties are expected:

Input

Description

Required?

Type

ruleSet

The RDF content with the SHACL shape extensions.

Yes

A string that is interpreted based on the embeddingMethod input.

embeddingMethod

The way in which to interpret the ruleSet input value.

Yes, but should be skipped in favour of the embeddingMethod attribute - see below.

One of BASE64 (for content embedded as a BASE64 encoded string), URI (for a reference to remote content) or STRING (for content embedded as-is).

ruleSyntax

The syntax to consider for the provided RDF content.

Yes, unless the content is provided as a URI for a file with a well-known extension.

A mime type string (e.g. text/turtle).

The GITB SOAP API that the validator realises foresees flexibility in how each provided value is interpreted. This is done via the embeddingMethod attribute that is defined on each input element. The values it supports are:

Value

Description

STRING

The value is interpreted as-is as an embedded text.

BASE64

The value is interpreted as an embedded BASE64 string that will need to be decoded before processing.

URI

The value is interpreted as a remote URI reference that will be looked up before processing.

Note

embeddingMethod values: The two approaches to provide the embeddingMethod value (as an input or an attribute) is due to a known issue in the GITB software where not all embedding methods can be leveraged within test cases (see Step 7: Use the validator in GITB TDL test cases).

The sample SOAP UI project includes sample requests per case. As an example, validating via URI would be done using the following envelope:

<?xml version="1.0" encoding="UTF-8"?>
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:v1="http://www.gitb.com/vs/v1/" xmlns:v11="http://www.gitb.com/core/v1/">
   <soapenv:Header/>
   <soapenv:Body>
      <v1:ValidateRequest>
         <sessionId>?</sessionId>
         <input name="contentToValidate" embeddingMethod="URI">
            <v11:value>https://www.itb.ec.europa.eu/files/samples/shacl/sample-invalid.ttl</v11:value>
         </input>
         <input name="validationType" embeddingMethod="STRING">
            <v11:value>large</v11:value>
         </input>
      </v1:ValidateRequest>
   </soapenv:Body>
</soapenv:Envelope>

A more complex case would be where user-provided SHACL shape extensions are provided (if allowed by the configuration). The following example submits content for validation via URI and provides two SHACL extension files, both provided as remote URI references:

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:v1="http://www.gitb.com/vs/v1/" xmlns:v11="http://www.gitb.com/core/v1/">
<soapenv:Header/>
<soapenv:Body>
    <v1:ValidateRequest>
        <sessionId>123</sessionId>
        <input name="contentToValidate" embeddingMethod="URI">
            <v11:value>https://www.itb.ec.europa.eu/files/samples/shacl/sample-invalid.ttl</v11:value>
        </input>
        <input name="validationType" embeddingMethod="STRING">
            <v11:value>large</v11:value>
        </input>
        <input name="externalRules">
            <v11:item>
                <v11:item name="ruleSet" embeddingMethod="URI">
                    <v11:value>https://path.to.rules/shape_extensions_1.ttl</v11:value>
                </v11:item>
            </v11:item>
            <v11:item>
                <v11:item name="ruleSet" embeddingMethod="URI">
                    <v11:value>https://path.to.rules/shape_extensions_2.ttl</v11:value>
                </v11:item>
            </v11:item>
        </input>
    </v1:ValidateRequest>
</soapenv:Body>
</soapenv:Envelope>

The resulting report in all cases is XML-based and uses the GITB TRL syntax:

<?xml version="1.0" encoding="UTF-8"?>
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
   <soap:Body>
      <ns4:ValidationResponse xmlns:ns2="http://www.gitb.com/core/v1/" xmlns:ns3="http://www.gitb.com/tr/v1/" xmlns:ns4="http://www.gitb.com/vs/v1/">
         <report name="SHACL Validation">
            <ns3:date>2019-06-24T15:42:45.959Z</ns3:date>
            <ns3:result>FAILURE</ns3:result>
            <ns3:counters>
               <ns3:nrOfAssertions>0</ns3:nrOfAssertions>
               <ns3:nrOfErrors>1</ns3:nrOfErrors>
               <ns3:nrOfWarnings>0</ns3:nrOfWarnings>
            </ns3:counters>
            <ns3:context type="map">
               <ns2:item name="input" embeddingMethod="STRING" type="string">
                  <ns2:value><![CDATA[@prefix ns0: <http://www.w3.org/ns/locn#> .
@prefix ns1: <http://itb.ec.europa.eu/sample/po#> .

<http://my.sample.po/po#home>
  a <http://www.w3.org/ns/locn#Address> ;
  ns0:fullAddress "Rue du Test 123, 1000 - Brussels, Belgium" ;
  ns0:thoroughfare "Rue du Test" ;
  ns0:locatorDesignator "123" ;
  ns0:postCode "1000" ;
  ns0:postName "Brussels" ;
  ns0:adminUnitL1 "BE" .

<http://my.sample.po/po#purchaseOrder>
  a <http://itb.ec.europa.eu/sample/po#PurchaseOrder> ;
  ns1:shipTo <http://my.sample.po/po#home> ;
  ns1:hasItem <http://my.sample.po/po#item1> ;
  ns1:hasItem <http://my.sample.po/po#item2> .

<http://my.sample.po/po#item1>
  a ns1:Item ;
  ns1:productName "Mouse" ;
  ns1:quantity 20 ;
  ns1:priceEUR 15.99 .

<http://my.sample.po/po#item2>
  a ns1:Item ;
  ns1:productName "Keyboard" ;
  ns1:quantity 3 ;
  ns1:priceEUR 25.50 .]]></ns2:value>
               </ns2:item>
               <ns2:item name="shapes" embeddingMethod="STRING" type="string">
                  <ns2:value><![CDATA[<rdf:RDF
    xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
    xmlns:po="http://itb.ec.europa.eu/sample/po#"
    xmlns:locn="http://www.w3.org/ns/locn#"
    xmlns:sh="http://www.w3.org/ns/shacl#"
    xmlns:xsd="http://www.w3.org/2001/XMLSchema#">
  <sh:NodeShape rdf:about="http://itb.ec.europa.eu/sample/po#LargeItemShape">
    <sh:targetClass rdf:resource="http://itb.ec.europa.eu/sample/po#Item"/>
    <sh:property>
      <sh:PropertyShape rdf:about="http://itb.ec.europa.eu/sample/po#minimumItemsForLargeOrderShape">
        <sh:path rdf:resource="http://itb.ec.europa.eu/sample/po#quantity"/>
        <sh:minExclusive rdf:datatype="http://www.w3.org/2001/XMLSchema#integer"
        >10</sh:minExclusive>
        <sh:severity rdf:resource="http://www.w3.org/ns/shacl#Violation"/>
      </sh:PropertyShape>
    </sh:property>
  </sh:NodeShape>
  <sh:NodeShape rdf:about="http://itb.ec.europa.eu/sample/po#ItemShape">
    <sh:targetClass rdf:resource="http://itb.ec.europa.eu/sample/po#Item"/>
    <sh:property>
      <sh:PropertyShape rdf:about="http://itb.ec.europa.eu/sample/po#productNameShape">
        <sh:path rdf:resource="http://itb.ec.europa.eu/sample/po#productName"/>
        <sh:minCount rdf:datatype="http://www.w3.org/2001/XMLSchema#integer"
        >1</sh:minCount>
        <sh:maxCount rdf:datatype="http://www.w3.org/2001/XMLSchema#integer"
        >1</sh:maxCount>
        <sh:nodeKind rdf:resource="http://www.w3.org/ns/shacl#Literal"/>
        <sh:severity rdf:resource="http://www.w3.org/ns/shacl#Violation"/>
      </sh:PropertyShape>
    </sh:property>
    <sh:property>
      <sh:PropertyShape rdf:about="http://itb.ec.europa.eu/sample/po#quantityShape">
        <sh:path rdf:resource="http://itb.ec.europa.eu/sample/po#quantity"/>
        <sh:minCount rdf:datatype="http://www.w3.org/2001/XMLSchema#integer"
        >1</sh:minCount>
        <sh:maxCount rdf:datatype="http://www.w3.org/2001/XMLSchema#integer"
        >1</sh:maxCount>
        <sh:datatype rdf:resource="http://www.w3.org/2001/XMLSchema#integer"/>
        <sh:minExclusive rdf:datatype="http://www.w3.org/2001/XMLSchema#integer"
        >0</sh:minExclusive>
        <sh:severity rdf:resource="http://www.w3.org/ns/shacl#Violation"/>
      </sh:PropertyShape>
    </sh:property>
    <sh:property>
      <sh:PropertyShape rdf:about="http://itb.ec.europa.eu/sample/po#priceShape">
        <sh:path rdf:resource="http://itb.ec.europa.eu/sample/po#priceEUR"/>
        <sh:minCount rdf:datatype="http://www.w3.org/2001/XMLSchema#integer"
        >1</sh:minCount>
        <sh:maxCount rdf:datatype="http://www.w3.org/2001/XMLSchema#integer"
        >1</sh:maxCount>
        <sh:datatype rdf:resource="http://www.w3.org/2001/XMLSchema#decimal"/>
        <sh:severity rdf:resource="http://www.w3.org/ns/shacl#Violation"/>
      </sh:PropertyShape>
    </sh:property>
  </sh:NodeShape>
  <sh:NodeShape rdf:about="http://itb.ec.europa.eu/sample/po#PurchaseOrderShape">
    <sh:targetClass rdf:resource="http://itb.ec.europa.eu/sample/po#PurchaseOrder"/>
    <sh:property>
      <sh:PropertyShape rdf:about="http://itb.ec.europa.eu/sample/po#shipToShape">
        <sh:path rdf:resource="http://itb.ec.europa.eu/sample/po#shipTo"/>
        <sh:minCount rdf:datatype="http://www.w3.org/2001/XMLSchema#integer"
        >1</sh:minCount>
        <sh:maxCount rdf:datatype="http://www.w3.org/2001/XMLSchema#integer"
        >1</sh:maxCount>
        <sh:class rdf:resource="http://www.w3.org/ns/locn#Address"/>
        <sh:severity rdf:resource="http://www.w3.org/ns/shacl#Violation"/>
      </sh:PropertyShape>
    </sh:property>
    <sh:property>
      <sh:PropertyShape rdf:about="http://itb.ec.europa.eu/sample/po#billToShape">
        <sh:path rdf:resource="http://itb.ec.europa.eu/sample/po#billTo"/>
        <sh:class rdf:resource="http://www.w3.org/ns/locn#Address"/>
        <sh:maxCount rdf:datatype="http://www.w3.org/2001/XMLSchema#integer"
        >1</sh:maxCount>
        <sh:severity rdf:resource="http://www.w3.org/ns/shacl#Violation"/>
      </sh:PropertyShape>
    </sh:property>
    <sh:property>
      <sh:PropertyShape rdf:about="http://itb.ec.europa.eu/sample/po#hasItemsShape">
        <sh:path rdf:resource="http://itb.ec.europa.eu/sample/po#hasItem"/>
        <sh:minCount rdf:datatype="http://www.w3.org/2001/XMLSchema#integer"
        >1</sh:minCount>
        <sh:class rdf:resource="http://itb.ec.europa.eu/sample/po#Item"/>
        <sh:severity rdf:resource="http://www.w3.org/ns/shacl#Violation"/>
      </sh:PropertyShape>
    </sh:property>
  </sh:NodeShape>
</rdf:RDF>]]></ns2:value>
               </ns2:item>
            </ns3:context>
            <ns3:reports>
               <ns3:error xsi:type="ns3:BAR" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
                  <ns3:description>Value is not > 10^^http://www.w3.org/2001/XMLSchema#integer</ns3:description>
                  <ns3:location>Focus node [http://my.sample.po/po#item2] - Result path [http://itb.ec.europa.eu/sample/po#quantity]</ns3:location>
                  <ns3:test>Shape [http://itb.ec.europa.eu/sample/po#minimumItemsForLargeOrderShape] - Value [3]</ns3:test>
               </ns3:error>
            </ns3:reports>
         </report>
      </ns4:ValidationResponse>
   </soap:Body>
</soap:Envelope>

The report includes:

  • The validation timestamp (in UTC).

  • The overall result (SUCCESS or FAILURE).

  • The count of errors, warnings and information messages.

  • The context for the validation, i.e. the content that was validated and the applied SHACL shapes, depending on the addInputToReport and addRulesToReport input values.

  • The list of report items displaying per item its description, location in the validated content (using the focus node and path) and performed test (using the applied shape’s name and the tested value).

Validation via command-line tool

Note

Command-line tool availability: Command-line tools are supported only for validators hosted on test bed resources and if generation of such a tool has been requested (see Step 5: Setup validator on test bed).

When a command line tool is set up for your validator it is available as an executable JAR file, packaged alongside a README file in a ZIP archive. This ZIP archive is downloadable from a URL of the form https://www.itb.ec.europa.eu/shacl-offline/DOMAIN/validator.zip, where DOMAIN is the name of the validator’s domain. Considering our purchase order example, the command-line validator would be available at https://www.itb.ec.europa.eu/shacl-offline/order/validator.zip.

To use it you need to:

  1. Ensure you have Java running on your workstation (minimum version 11).

  2. Download and extract the validator’s ZIP archive.

  3. Open a command prompt and change to the directory in which you extracted the JAR file.

  4. View the validator’s help message by issuing java -jar validator.jar

> java -jar validator.jar

Expected usage: java -jar validator.jar [-noreports] [-reportSyntax REPORT_SYNTAX] -contentToValidate FILE_1/URI_1 CONTENT_SYNTAX_1 ... [-contentToValidate FILE_N/URI_N CONTENT_SYNTAX_N] [-externalShapes SHAPE_FILE_1/SHAPE_URI_1 CONTENT_SYNTAX_1] ... [-externalShapes SHAPE_FILE_N/SHAPE_URI_N CONTENT_SYNTAX_N] [-locale LOCALE]
Where:
    - REPORT_SYNTAX is the mime type for the validation report(s).
    - FILE_X or URI_X is the full file path or URI to the content to validate, optionally followed by CONTENT_SYNTAX_X as the content's mime type.
    - SHAPE_FILE_X or SHAPE_URI_X is the full file path or URI to additional shapes to consider, optionally followed by CONTENT_SYNTAX_X as the shapes' mime type.
    - LOAD_IMPORTS is a boolean indicating whether the owl:Imports should be loaded (true) or not (false).
    - LOCALE is the language code to consider for reporting of results. If the provided locale is not supported by the validator the default locale will be used instead (e.g. 'fr', 'fr_FR').

The summary of each validation will be printed and the detailed report produced in the current directory (as "report.X.SUFFIX").

In short, the validator can be used to validate one or more local or remote RDF files. If not possible to determine automatically, you may also specify the content type of each input, and also specify the content type for the output reports (reverting to the configured default if unspecified). Alternatively, if SPARQL queries are supported, you may also provide as input the SPARQL query to execute via the relevant flags (-contentQuery, -contentQueryEndpoint, -contentQueryUsername, -contentQueryPassword).

Running the validator will produce a summary output on the command console as well as the detailed validation report(s) (unless flag -noreports has been specified). To resolve potential problems during execution, an output log is also generated with a detailed log trace.

> java -jar validator.jar -contentToValidate https://www.itb.ec.europa.eu/files/samples/shacl/sample.ttl

Validating [https://www.itb.ec.europa.eu/files/samples/shacl/sample.ttl]... Done.


Validation report summary [https://www.itb.ec.europa.eu/files/samples/shacl/sample.ttl]:
- Date: 2019-09-03T08:41:24.802+02:00
- Result: SUCCESS
- Errors: 0
- Warnings: 0
- Messages: 0
- Detailed report in: [D:\temp\validator\order\report.0.jsonld]

Note

Offline validator use and remote resources: Depending on the validator’s configuration, one or more of its SHACL files may be defined as URIs (see Step 3: Prepare validator configuration). In addition, you may also provide the content to validate as a reference to a remote file or as a query to be executed against a remote SPARQL endpoint. In these cases the workstation running the validator would need access to the remote resources. Any proxy settings applicable for the workstation will automatically be used for the connections.

Step 7: Use the validator in GITB TDL test cases

As a next step over the standalone validator you may consider using it from within GITB TDL test cases running in the test bed. You would typically do this for the following reasons:

  • You want to control access to the validation service based on user accounts.

  • You prefer to record all data linked to validations (for e.g. subsequent inspection).

  • You want to build complete conformance testing scenarios that are either focused on the validator or that use it as part of validation steps.

As described in Validation via SOAP web service API, the standalone validator offers by default a SOAP API for machine-to-machine integration that realises the GITB validation service specification. In short this means that the service can be easily included in any GITB TDL test case as the handler of a verify step by supplying as its value the full URL to the service’s WSDL.

The following example is a test case that validates purchase orders as being large. The input content is requested as a file from the user as well as the syntax to consider (based on a predefined set of options):

<?xml version="1.0" encoding="UTF-8"?>
<testcase id="testCase1_upload" xmlns="http://www.gitb.com/tdl/v1/" xmlns:gitb="http://www.gitb.com/core/v1/">
    <metadata>
        <gitb:name>testCase1_upload</gitb:name>
        <gitb:version>1.0</gitb:version>
        <gitb:description>Test case that allows the developer of an EU retailer system to upload a purchase order for validation as being considered large.</gitb:description>
    </metadata>
    <actors>
        <gitb:actor id="Retailer" name="Retailer" role="SUT"/>
    </actors>
    <steps>
        <!--
            Request from the user the content to validate as a file and its syntax.
        -->
        <interact id="userData" desc="Upload content">
            <request name="content" desc="Purchase order to validate:" contentType="BASE64"/>
            <request name="syntax" desc="Content syntax:" options="application/json+ld, application/rdf+xml, text/turtle" optionLabels="JSON-LD, RDF/XML, Turtle"/>
        </interact>
        <!--
            Trigger the validation.
        -->
        <verify handler="https://www.itb.ec.europa.eu/shacl/soap/order/validation?wsdl" desc="Validate purchase order">
            <input name="contentToValidate">$userData{content}</input>
            <input name="contentSyntax">$userData{syntax}</input>
            <input name="validationType">"large"</input>
        </verify>
    </steps>
</testcase>

Note that the input names (contentToValidate, contentSyntax and validationType) correspond to those expected by the SOAP API (see Validation via SOAP web service API). For string or binary content you typically don’t need to provide the embeddingMethod as this is determined automatically by the test bed. If however you are using string variables that contain BASE64 or URI references you would need to define this explicitly.

An example of this is a test case that requests the content from the user as a URI:

<testcase id="testCase1_upload" xmlns="http://www.gitb.com/tdl/v1/" xmlns:gitb="http://www.gitb.com/core/v1/">
    ...
    <steps>
        <!--
            Request from the user the content to validate as a URI.
            The syntax will be determined from the file's extension.
        -->
        <interact id="userData" desc="Provide input">
            <request name="content" desc="URI of the purchase order to validate:"/>
        </interact>
        <!--
            Trigger the validation.
        -->
        <verify handler="https://www.itb.ec.europa.eu/shacl/soap/order/validation?wsdl" desc="Validate purchase order">
            <input name="contentToValidate">$userData{content}</input>
            <!--
                Explicitly define the embeddingMethod to consider.
            -->
            <input name="embeddingMethod">"URL"</input>
            <input name="validationType">"large"</input>
        </verify>
    </steps>
</testcase>

A more complicated example is when external SHACL shapes are to be provided (if supported for the validation type in question). The following example shows two such extensions being provided, one as a URI and one from a file included in the test suite itself:

<?xml version="1.0" encoding="UTF-8"?>
<testcase id="testCase1_upload" xmlns="http://www.gitb.com/tdl/v1/" xmlns:gitb="http://www.gitb.com/core/v1/">
    ...
    <imports>
        <!--
            Import the additional shapes to consider from the test suite.
        -->
        <artifact type="binary" name="additionalShapes">resources/additional-shapes.ttl</artifact>
    </imports>
    <variables>
        <!--
            Define variables for the SHACL shape extensions.
        -->
        <var name="externalRules" type="list[map]"/>
        <!--
            First set of rules defined through a URL reference.
            The "ruleSyntax" is not needed as it can be determined from the referenced file.
        -->
        <var name="ruleSet1" type="map">
            <value name="ruleSet" type="string">https://path.to.rules/shape_extensions.ttl</value>
            <value name="embeddingMethod" type="string">URL</value>
        </var>
        <!--
            Second set of rules defined as BASE64 (to be assigned once the test starts).
            The "embeddingMethod" will be automatically set given that a file will be used.
        -->
        <var name="ruleSet2" type="map">
            <value name="ruleSyntax" type="string">text/turtle</value>
        </var>
    </variables>
    ...
    <steps>
        <!--
            Add as the "ruleSet" value the imported shapes from the test suite.
            This will also automatically set the "embeddingMethod" to "BASE64".
        -->
        <assign to="$ruleSet2{ruleSet}" type="binary">$additionalShapes</assign>
        <!--
            Add both additional sets of rules to the input list.
        -->
        <assign to="$externalRules" append="true">$ruleSet1</assign>
        <assign to="$externalRules" append="true">$ruleSet2</assign>
        <interact id="userData" desc="Upload content">
            <request name="content" desc="Purchase order to validate:" contentType="BASE64"/>
            <request name="syntax" desc="Content syntax:" options="application/json+ld, application/rdf+xml, text/turtle" optionLabels="JSON-LD, RDF/XML, Turtle"/>
        </interact>
        <verify handler="https://www.itb.ec.europa.eu/shacl/soap/order/validation?wsdl" desc="Validate purchase order">
            <input name="contentToValidate">$userData{content}</input>
            <input name="contentSyntax">$userData{syntax}</input>
            <input name="validationType">"large"</input>
            <!--
                Pass the list of additional shapes to consider.
            -->
            <input name="externalRules">$externalRules</input>
        </verify>
    </steps>
</testcase>

One additional point to make is on the definition of the service’s WSDL (i.e. the handler value). Although you can define this directly as in the previous examples, a better approach to improve portability is to define this in the test bed’s domain configuration as a domain parameter. Defining a validationService parameter in the domain you could thus redefine the verify step as:

...
<verify handler="$DOMAIN{validationService}" desc="Validate purchase order">
    ...
</verify>
...

Summary

Congratulations! You have just setup a validation service for your RDF specification. In doing so you considered your needs and defined your service through configuration on the DIGIT test bed or as a Docker container. In addition, you used this service via its different APIs and considered how this could be used as part of complete conformance testing scenarios.

See also

The validator for the fictional specification considered in this guide is available as a demo that you can use. The validator is available here, whereas its domain configuration repository is published as a sample on GitHub.

In Step 7: Use the validator in GITB TDL test cases we briefly touched upon using the test bed for complete conformance testing scenarios. If this interests you, several additional guides are available that can provide you with further information:

For the full information on GITB TDL test cases check out the GITB TDL documentation, the reference for all test step constructs as well as a source of numerous complete examples.

In case you need to consider validation of further content types, be aware that the test bed provides similar support for:

If you are planning on operating a validator on your own-premises for production use check the validator production installation guide for the steps to follow and guidelines to consider.

Finally, for more information on Docker and the commands used in this guide, check out the Docker online documentation.

References

This section contains additional references linked to this guide.

Validator configuration properties

The following sections list the configuration properties you can use to customise the operation of your validation service.

Domain-level configuration

The properties in this section are to be provided in the configuration property file (one per configured validation domain) you define as part of your validator configuration. The properties marked as being translatable (in the listed property Type) may also be defined in translation property files if the validator is configured to support multiple languages (see Supporting multiple languages).

Note

Property placeholders: Numerous configuration properties listed below are presented with placeholders. These are marked in uppercase and have the following meaning:

  • TYPE: The validation type to perform.

  • OPTION: An option for a given validation type (e.g. a specific version).

  • FULL_TYPE: For a validation type with options this is equals to TYPE.OPTION, otherwise it is the TYPE value itself.

  • N: A zero-based integer (used as a counter).

Property

Description

Type

Default value

validator.addBOMToCSVExports

Whether or not a UTF-8 BOM (Byte Order Mark) should be added when generating validation reports in CSV format.

Boolean

true

validator.bannerHtml

Configurable HTML banner replacing the text title.

String (translatable)

validator.channels

Comma-separated list of validation channels to have enabled. Possible values are (form, rest_api, soap_api).

Comma-separated Strings

form, rest_api, soap_api

validator.completeTypeOptionLabel.TYPE.OPTION

Label to display for the full validation type and option combination (visible in the validator’s result screen).

String (translatable)

validator.contentSyntax

The RDF content syntaxes (as mime types) that the web user interface will support for input and output.

Comma-separated Strings

application/ld+json, application/rdf+xml, text/turtle, application/n-triples

validator.defaultPlugins.N.class

Paired with the its corresponding jar property (see above), this defines the fully qualified names of the classes to be loaded as plugin implementations.

Comma-separated Strings

validator.defaultPlugins.N.jar

Configuration for custom plugins that can be used to extend the validation. This is a default plugin definition that applies to all validation types. This property is the relative path pointing to the all-in-one JAR file that contains the plugin implementation(s).

String

validator.defaultReportSyntax

The default report syntax to be returned if none is explicitly requested.

String (as mime type)

application/rdf+xml

validator.defaultType

The default validation type, considered if no type is indicated.

String

validator.externalShapes.FULL_TYPE

Whether or not user-provided shapes are allowed for the given validation type (added as a postfix). Possible values are (required, optional, none).

String

none

validator.footerHtml

Configurable HTML banner for the footer.

String (translatable)

validator.importProperties

The path of a file declaring additional domain properties. If the application property validator.restrictResourcesToDomain is set to true or omitted, only relative paths of files under the domain root folder are accepted.

String

validator.input.loadImports

Whether or not the user can specify if imports should be loaded when loading the data graph to validate. Possible values are (required, optional, none).

String

none

validator.input.loadImports.FULL_TYPE

Whether or not the user can specify if imports should be loaded when loading the data graph to validate for a given validation type (added as a postfix). Possible values are (required, optional, none).

String

none

validator.input.preprocessor.FULL_TYPE

A SPARQL CONSTRUCT query to be used for the preprocessing of input before proceeding to validate.

String

validator.loadImports

Whether or not imports should be loaded when loading the data graph to validate.

Boolean

false

validator.loadImports.FULL_TYPE

Whether or not imports should be loaded when loading the data graph to validate for the given validation type (added as a postfix).

Boolean

false

validator.locale.available

The list of locales (language codes) that will be available for the user to select. This is provided as a comma-separated set of String values, the order of which determines the order that they will be listed in the UI’s language selection control.

Comma-separated Strings

validator.locale.default

The default locale (language code) to consider for the validator. This can be provided alone or with a country variant (e.g. “en”, “en_US”, “en_GB”).

String

en

validator.locale.translations

The path to a folder (absolute or relative to the domain configuration file) that contains the translation property files for the validator’s supported languages.

String

validator.maximumReportsForDetailedOutput

The maximum number of report items for which a PDF validation report will be generated (no report will be preoduced if exceeded).

Integer

5000

validator.maximumReportsForXmlOutput

The maximum number of report items to include in the XML validation report.

Integer

50000

validator.mergeModelsBeforeValidation

Before validating merge the data graph with the shape graph. This is done to ensure that any vocabularies defines as part of the test configuration also provide context to the considered data graph.

Boolean

true

validator.optionLabel.OPTION

Label to display in the web form for an option across all validation types (added as a postfix of validator.optionLabel). Only displayed if there are options defined.

String (translatable)

validator.owlImportErrors

The default handling approach for errors raised when resolving owl:imports. Possible values are fail (log, stop processing are report error), warn (log, continue processing but report a warning), log (log and continue processing).

String

log

validator.owlImportErrors.FULL_TYPE

The handling approach for a given validation type for errors raised when resolving owl:imports. Possible values are fail (log, stop processing are report error), warn (log, continue processing but report a warning), log (log and continue processing).

String

log

validator.owlImportErrorsIgnoredUris

The set of URIs for which owl:imports errors should be ignored.

Comma-separated Strings

validator.owlImportSkippedUris

The set of URIs for which owl:imports should be altogether skipped.

Comma-separated Strings

validator.plugins.FULL_TYPE.N.class

Paired with the its corresponding jar property (see above), this defines the fully qualified names of the classes to be loaded as plugin implementations.

Comma-separated Strings

validator.plugins.FULL_TYPE.N.jar

Configuration for custom plugins that can be used to extend the validation specific to a given type (FULL_TYPE) and extending any default plugins (see above). This property is the relative path pointing to the all-in-one JAR file that contains the plugin implementation(s).

String

validator.queryAuthenticationInput

If queries are supported and no username or password are configured, this can be used to set whether authentication is required, optional or never expected. Possible values are required, optional and none.

String

none when credentials are preconfigured and optional otherwise.

validator.queryEndpoint

The SPARQL endpoint to execute queries against (when query input is supported). If queries are supported and no endpoint is configured, this will be expected to be provided as input.

String

validator.queryPassword

The password to use for authentication against the configured SPARQL endpoint (when query input is supported). If not configured this will be expected as an optional input (optional for anonymous usage).

String

validator.queryPreferredContentType

The RDF syntax (provided as a mime type string) to request as a result from the SPARQL endpoint. Possible values are application/ld+json, application/rdf+xml, text/turtle and application/n-triples

String

application/rdf+xml

validator.queryUsername

The username to use for authentication against the configured SPARQL endpoint (when query input is supported). If not configured this will be expected as an optional input (optional for anonymous usage).

String

validator.remoteArtefactLoadErrors

The default handling approach for errors raised when downloading pre-configured remote artefacts. Possible values are fail (log, stop processing are report error), warn (log, continue processing but report a warning), log (log and continue processing).

String

log

validator.remoteArtefactLoadErrors.FULL_TYPE

The handling approach for a given validation type for errors raised when downloading pre-configured remote artefacts. Possible values are fail (log, stop processing are report error), warn (log, continue processing but report a warning), log (log and continue processing).

String

log

validator.reportsOrdered

Whether the report items are to be ordered (errors first, then warnings, then messages). Otherwise the items will appear based on where they were raised in the validated content.

Boolean

false

validator.reportItemAdditionalInfoTemplate

A template expression to apply on a report item’s focus node to produce an additional information text. This is applied in case there is no mode specific template to consider based on the focus node’s rdf:type.

String

validator.reportItemAdditionalInfoTemplate.N.type

When including additional information for a report item’s focus node, this defines an rdf:type for which a specific template should be applied. One or more such entries can be defined by incrementing the zero-based N counter.

String

validator.reportItemAdditionalInfoTemplate.N.template

When including additional information for a report item’s focus node, this defines the template expression to use for a specific rdf:type. One or more such entries can be defined by incrementing the zero-based N counter.

String

validator.returnMessagesForAllLocales

If shapes are defined with result messages for multiple locales, return all messages in the SHACL validation report regardless of the requested locale.

Boolean

false

validator.shaclFile.FULL_TYPE

Comma-separated list of SHACL shape files loaded for a given validation type (added as a postfix). These can be a files or folders.

Comma-separated Strings

validator.shaclFile.FULL_TYPE.remote.N.type

The content type for the remotely loaded SHACL shape file defined in the corresponding validator.shaclFile.FULL_TYPE.remote.N.url property. This can be skipped if the type can be determined from the referenced file name.

String (as mime type)

validator.shaclFile.FULL_TYPE.remote.N.url

Reference for a remotely loaded SHACL shape file for a given validation type (added as the FULL_TYPE placeholder). One or more such entries can be defined by incrementing the zero-based N counter.

String

validator.showAbout

Whether or not to show the about panel on the web UI.

Boolean

true

validator.supportsQueries

Whether or not SPARQL queries are supported to generate the input. If any other query-related properties are defined this is assume to be true.

Boolean

false

validator.supportMinimalUserInterface

Enable a minimal user interface useful for embedding in other UIs or portals (applies only if the form validation channel is enabled).

Boolean

false

validator.supportUserInterfaceEmbedding

Allow the validator to be embedded within other user interfaces by displaying it in iframes.

Boolean

true

validator.type

Comma-separated list of supported validation types. Values need to be reflected in the other properties’ TYPE and FULL_TYPE placeholders. FULL_TYPE equals TYPE.OPTION (in case type options are defined) or simply TYPE if there are no options (see also validator.typeOptions).

Comma-separated Strings

validator.typeLabel.TYPE

Label to display in the web form for a given validation type (added as a postfix of validator.typeLabel). Only displayed if there are multiple types.

String (translatable)

validator.typeOptions.TYPE

Comma-separated list of options defined for a given validation type (added as a postfix). Values need to be reflects in the other properties’ OPTION and FULL_TYPE placeholders. FULL_TYPE equals TYPE.OPTION (in case type options are defined) or simply TYPE if there are no options (see also validator.type).

Comma-separated Strings

validator.typeOptionLabel.TYPE.OPTION

Label to display for an option for a specific validation type.

String (translatable)

validator.webServiceDescription.contentToValidate

The description of the SOAP web service for element “contentToValidate”.

String

The content to validate, provided as a string, BASE64 or a URI.

validator.webServiceDescription.contentSyntax

The description of the SOAP web service for element “contentSyntax”.

String

The mime type of the provided content.

validator.webServiceDescription.validationType

The description of the SOAP web service for element “validationType”. Only displayed if there are multiple types.

String

The type of validation to perform (if multiple types are supported).

validator.webServiceDescription.externalRules

The description of the SOAP web service for element “externalRules”.

String

A list of maps that defines external SHACL shapes to consider in addition to any preconfigured ones. Each map item corresponds to a SHACL file and defines the following keys: ‘ruleSet’ (the rules to consider, see ‘contentToValidate’ for its semantics), ‘ruleSyntax’ (the syntax of the ‘ruleSet’ content, see ‘contentSyntax’ for its semantics), ‘embeddingMethod’ (the way to consider the ‘ruleSet’ value).

validator.webServiceDescription.embeddingMethod

The description of the SOAP web service for element “embeddingMethod”.

String

The embedding method to consider for the ‘contentToValidate’ input (‘BASE64’, ‘URL’ or ‘STRING’).

validator.webServiceDescription.loadImports

The description of the SOAP web service for element “loadImports”.

String

Whether owl:Imports should be loaded (true) or not (false).

validator.webServiceDescription.addInputToReport

The description of the SOAP web service for element “addInputToReport”.

String

Whether the returned XML validation report should also include the validated input as context information.

validator.webServiceDescription.addRulesToReport

The description of the SOAP web service for element “addRulesToReport”.

String

Whether the returned XML validation report should also include the SHACL shapes used for the validation as context information.

validator.webServiceDescription.addRdfReportToReport

The description of the SOAP web service for element “addRdfReportToReport”.

String

Whether or not the raw RDF report should be returned as part of the resulting context information.

validator.webServiceDescription.rdfReportSyntax

The description of the SOAP web service for element “rdfReportSyntax”.

String

The mime type for the raw RDF report returned as part of the resulting context (if included).

validator.webServiceDescription.rdfReportQuery

The description of the SOAP web service for element “rdfReportQuery”.

String

A post-processing SPARQL CONSTRUCT query to run on the RDF report before returning it in the resulting context.

validator.webServiceDescription.contentQuery

The description of the SOAP web service for element “contentQuery”.

String

The SPARQL query to execute to retrieve the content to validate.

validator.webServiceDescription.contentQueryEndpoint

The description of the SOAP web service for element “contentQueryEndpoint”.

String

The URI for the SPARQL endpoint to execute queries against.

validator.webServiceDescription.contentQueryUsername

The description of the SOAP web service for element “contentQueryUsername”.

String

The username to authenticate against the SPARQL endpoint.

validator.webServiceDescription.contentQueryPassword

The description of the SOAP web service for element “contentQueryPassword”.

String

The password to authenticate against the SPARQL endpoint.

validator.webServiceDescription.locale

The description of the SOAP web service for element “locale”.

String

Locale (language code) to use for reporting of results. If the provided locale is not supported by the validator the default locale will be used instead (e.g. “fr”, “fr_FR”).

validator.webServiceId

The ID of the SOAP web service.

String

ValidatorService

Note

Configuration of sensitive values: If you are enabling SPARQL queries for your validator and are preconfiguring the endpoint’s password you will likely want to not include its value in the configuration file. For this and other sensitive properties (e.g. internal URLs) check Environment-specific domain configuration to see how they can be externalised.

Application-level configuration

These properties govern the validator’s application instance itself. They apply only when you are defining your own validator as a Docker image in which case they are supplied as environment variables (ENV directives in a Dockerfile). Note that apart from these properties any Spring Boot configuration property can also be supplied.

Note

Mandatory property: The only mandatory property that needs to be defined is validator.resourceRoot.

Property

Description

Type

Default value

logging.file.path

Path to a folder that will hold the validator’s log output.

String

/validator/logs

validator.acceptedHeaderAcceptTypes

Accepted Accept header syntaxes for the report type (used in the REST API).

Comma-separated Strings

application/rdf+xml, application/ld+json, text/turtle, , application/n-triples

validator.acceptedShaclExtensions

Accepted local SHACL file extensions. All other files found in validator.shaclFile.FULL_TYPE (when folders are defined) are ignored.

Comma-separated Strings

rdf, ttl, jsonld

validator.cleanupRate

The rate at which the external file cache is refreshed (in milliseconds).

Long

3600000

validator.cleanupWebRate

The rate at which temporary files linked to the web form are cleaned (in milliseconds).

Long

600000

validator.contentSyntax

Global default supported content syntaxes for the web upload form if not overriden at domain level.

Comma-separated Strings

application/ld+json, application/rdf+xml, text/turtle, application/n-triples

validator.defaultReportSyntax

Global default report syntax, applied if not overriden at domain level or by the user’s request.

String (as mime type)

application/rdf+xml

validator.docs.host

The host to display as the root for the REST API Swagger documentation.

String

localhost:8080

validator.docs.licence.description

Description of the licence in the Swagger UI.

String,

European Union Public Licence (EUPL) 1.2

validator.docs.licence.url

URL to the licence for the Swagger UI.

String,

https://eupl.eu/1.2/en/

validator.docs.schemes

Comma-separated scheme values for the Swagger documentation

Comma-separated Strings

http

validator.docs.title

Title to display in the Swagger UI.

String,

SHACL Validator REST API

validator.docs.version

Version number to display in the Swagger UI.

String,

1.0.0

validator.domain

The names of the domain subfolders to consider. By default all folders under validator.resourceRoot will be considered.

Comma-separated Strings

validator.domainName.DOMAIN

The name to display for a given domain folder (the folder name replacing the DOMAIN placeholder). This value will also be used in request paths.

String

The folder name is used.

validator.hydraRootPath

The root path to append to the validator.hydraServer for the Hydra documentation of the REST API.

String

${server.servlet.context-path}

validator.hydraServer

The server part to add as of the REST API’s vocabulary’s URL for the Hydra documentation.

String

http://localhost:${server.port}

validator.identifier

The validator’s identifier to be sent for usage statistics reporting.

String

rdf

validator.queryPreferredContentType

In case SPARQL queries are supported, this is the default content type requested as queries’ output.

String

application/rdf+xml

validator.resourceRoot

The root folder under which domain subfolders will be loaded from.

String

validator.restrictResourcesToDomain

Whether local validation artefacts can be loaded from outside the domain root folder. If false, both relative and absolute paths are accepted.

Boolean

true

validator.tmpFolder

Path to a folder that contains temporary data and reports.

String

/validator/tmp

validator.webhook.ipheader

The HTTP header to use to retrieve the user’s IP address for usage statistics if the validator is behind a proxy. This property is only used to detect the user’s country, when such feature is enabled (see validator.webhook.statisticsEnableCountryDetection).

String

X-Real-IP

validator.webhook.statistics

The URL of the backend service that will collect usage statistics. This property is optional and, if (and only if) present, the validator will report usage statistics.

String

validator.webhook.statisticsCountryDetectionDbFile

The path to the .mmdb file with the geolocation database that is used to resolve the user’s country from an IP address. This database will only be used when the property validator.webhook.statisticsEnableCountryDetection takes the value true.

String

validator.webhook.statisticsEnableCountryDetection

Whether the usage statistics reporting service can detect users’ countries from their IP addresses. If false no information about the user’s country or IP address will be reported.

Boolean

false

validator.webhook.statisticsSecret

The validator client secret to be passed to the backend service for usage statistics reporting.

String

Change history