Vocabulary Validation

Validate a vocabulary

Vocabulary validation checks the structure of the vocabulary graph by applying SHACL rules using the pySHACL library[^modified]. The SHACL rules are located in vocab_tools/data and are included with the code when this packae is installed.

1: The version of pySHACL used here is slightly modified to provide more metrics on rules applied during the validation process. It is retrieved from github.com/datadavev/pyshacl and is kept in sync with changes from upstream.

  • 1 modified

    • Validation is generally performed on a single base or extension vocabulary using the vocab validate command with the target vocabulary source file as the only parameter:

    vocab validate --help
    Usage: vocab validate [OPTIONS] SOURCE

  Validate vocabulary structure.

Options:
  -v, --vocab TEXT  Vocabulary to load
  -s, --shape TEXT  SHACL shape file for vocabulary structure validation
  --help            Show this message and exit.

    Applying the rules against a valid vocabulary generates output similar to the following:

    vocab validate example/data/example.ttl
    Loaded vocabulary https://example.net/my/minimal/vocab
SHACL conformance: True

    If the vocabulary does not conform with the SHACL rules then error messages are emitted. These can sometimes be a bit difficult to dechipher, though the target node mentioned in the error output is a good starting point. This example shows the output when the vocabulary has no top concept (skos:topConceptOf):

    vocab validate example/data/example_notop.ttl
    Loaded vocabulary https://example.net/my/minimal/vocab
SHACL conformance: False
Vocabulary not in conformance. Skipping further tests.
Validation Report
Conforms: False
Results (2):
19 of 21 applied.
Constraint Violation in OrConstraintComponent (http://www.w3.org/ns/shacl#OrConstraintComponent):
    Severity: sh:Violation
    Source Shape: skos:VocabularyConceptShape
    Focus Node: eg:thing
    Value Node: eg:thing
    Message: Node eg:thing does not conform to one or more shapes in skos:NarrowerConceptShape , skos:TopConceptShape
Constraint Violation in OrConstraintComponent (http://www.w3.org/ns/shacl#OrConstraintComponent):
    Severity: sh:Violation
    Source Shape: skos:VocabularyShape
    Focus Node: eg:vocab
    Value Node: eg:vocab
    Message: Node eg:vocab does not conform to one or more shapes in skos:ExtensionVocabularyShape , skos:BaseVocabularyShape

    This example demonstrates output when the vocabulary has no skos:ConceptScheme:

    vocab validate example/data/example_noconceptscheme.ttl
    Loaded vocabulary does not specify skos:ConceptScheme
SHACL conformance: False
Vocabulary not in conformance. Skipping further tests.
Validation Report
Conforms: False
Results (2):
18 of 21 applied.
Constraint Violation in MinCountConstraintComponent (http://www.w3.org/ns/shacl#MinCountConstraintComponent):
    Severity: sh:Violation
    Source Shape: [ sh:description Literal("A vocabulary must have an instance of skos:ConceptScheme.", lang=en) ; sh:maxCount Literal("1", datatype=xsd:integer) ; sh:minCount Literal("1", datatype=xsd:integer) ; sh:path [ sh:inversePath rdf:type ] ]
    Focus Node: skos:ConceptScheme
    Result Path: [ sh:inversePath rdf:type ]
    Message: Less than 1 values on skos:ConceptScheme->[ sh:inversePath rdf:type ]
Constraint Violation in OrConstraintComponent (http://www.w3.org/ns/shacl#OrConstraintComponent):
    Severity: sh:Violation
    Source Shape: skos:VocabularyConceptShape
    Focus Node: eg:thing
    Value Node: eg:thing
    Message: Node eg:thing does not conform to one or more shapes in skos:NarrowerConceptShape , skos:TopConceptShape

    A vocabulary concept has no skos:prefLabel:

    vocab validate example/data/example_nolabel.ttl
    Loaded vocabulary https://example.net/my/minimal/vocab
SHACL conformance: False
Vocabulary not in conformance. Skipping further tests.
Validation Report
Conforms: False
Results (1):
21 of 21 applied.
Constraint Violation in MinCountConstraintComponent (http://www.w3.org/ns/shacl#MinCountConstraintComponent):
    Severity: sh:Violation
    Source Shape: [ sh:datatype rdf:langString ; sh:description Literal("A vocabulary concept must have a preferred name", lang=en) ; sh:minCount Literal("1", datatype=xsd:integer) ; sh:path skos:prefLabel ]
    Focus Node: eg:solid
    Result Path: skos:prefLabel
    Message: Less than 1 values on eg:solid->skos:prefLabel

    A vocabulary concept has no skos:definition:

    vocab validate example/data/example_nodefinition.ttl
    Loaded vocabulary https://example.net/my/minimal/vocab
SHACL conformance: False
Vocabulary not in conformance. Skipping further tests.
Validation Report
Conforms: False
Results (1):
21 of 21 applied.
Validation Result in MinCountConstraintComponent (http://www.w3.org/ns/shacl#MinCountConstraintComponent):
    Severity: sh:warning
    Source Shape: [ sh:datatype rdf:langString ; sh:description Literal("A vocabulary concept should have a textual definition", lang=en) ; sh:minCount Literal("1", datatype=xsd:integer) ; sh:path skos:definition ; sh:severity sh:warning ]
    Focus Node: eg:solid
    Result Path: skos:definition
    Message: Less than 1 values on eg:solid->skos:definition