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Validate Knowledge Graph¤

Python Plugin

This operator is part of a Python Plugin Package. In order to use it, you need to install it, e.g. with cmemc.

Starts a graph validation process which verifies that resources in a specific graph are valid according to the node shapes in a shape catalog graph. The task waits for the validation to finish before completing.

The task has no input port. Violations found during validation are always summarized in the workflow report, and can also be materialized into a result graph in the project. Sending each violation as an entity to an output port is optional; when that is disabled, the task has no output port either.

Error Handling¤

Every resource is validated regardless of the outcome. The task can then either:

  • Fail once validation completes if any resource has violations, halting the workflow.
  • Report violations only as warnings, allowing follow-up tasks to run based on the results.

The error handling behavior is configurable through the Fail workflow on violations parameter.

Parameter¤

Context Graph¤

This graph holds the resources you want to validate.

  • ID: context_graph
  • Datatype: scheme:string
  • Default Value: None

Shape graph¤

This graph holds the shapes you want to use for validation.

  • ID: shape_graph
  • Datatype: scheme:string
  • Default Value: https://vocab.eccenca.com/shacl/

Result graph¤

In this graph, the validation results are materialized. If left empty, results are not materialized.

  • ID: result_graph
  • Datatype: scheme:string
  • Default Value: None

Clear result graph before validation¤

If enabled, the existing content of the result graph is deleted before validation starts. Has no effect when Result graph is left empty.

  • ID: clear_result_graph
  • Datatype: boolean
  • Default Value: false

Fail workflow on violations¤

If enabled, the workflow fails once validation completes if any resource has violations. All resources are validated either way; disabling this instead reports the violations as warnings.

  • ID: fail_on_violations
  • Datatype: boolean
  • Default Value: false

Output violations as entities¤

If enabled, each violation is sent as an entity to an output port for further processing in the workflow. Disabling this removes the output port.

  • ID: output_results
  • Datatype: boolean
  • Default Value: true

Advanced Parameter¤

Resource Selection Query¤

The query to select the resources to validate. Use {{context_graph}} as a placeholder for the selected Context Graph.

  • ID: sparql_query
  • Datatype: code-sparql
  • Default Value:
SELECT DISTINCT ?resource
FROM <{{context_graph}}>
WHERE { ?resource a ?class . FILTER isIRI(?resource) }

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