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Caveats when working with a JSON project file

Referencing Ontologies

For several fields (e.g. super in both resources and properties, or propname in cardinalities), it is necessary to reference entities that are defined elsewhere. The following cases are possible:

  • DSP-API internals:
    • They are referenced as such and do not have a leading colon.
    • e.g. Resource, DocumentRepresentation or hasValue
  • An external ontology:
    • The ontology must be defined in the prefixes section.
    • The prefix can then be used for referencing the ontology.
    • e.g. foaf:familyName or sdo:Organization
  • The current ontology:
    • Within the same ontology, references can be made by prepending a colon without a prefix, e.g. :hasName.
    • Optionally, the current ontology can be referenced by its name, e.g. sameOnto:hasName
    • It is not necessary to add sameOnto to the prefixes.
  • A different ontology defined in the same file:
    • Within one data model file, multiple ontologies can be defined. These will be created in the exact order they appear in the ontologies array.
    • Once an ontology has been created, it can be referenced by the following ontologies by its name, e.g. first-onto:hasName.
    • It is not necessary to add first-onto to the prefixes.

DSP base resources and base properties to be used directly in the XML file

There is a number of DSP base resources that must not be subclassed in a project ontology. They are directly available in the XML data file:

  • Annotation is an annotation to another resource of any class. It can be used in the XML file with the <annotation> tag. It automatically has the following predefined properties:
    • hasComment (1-n)
    • isAnnotationOf (1)
  • LinkObj is a resource linking together several other resources of different classes. It can be used in the XML file with the <link> tag. It automatically has the following predefined properties:
    • hasComment (1-n)
    • hasLinkTo (1-n)
  • A Region resource defines a region of interest (ROI) in an image. It can be used in the XML file with the <region> tag. It automatically has the following predefined properties:
    • hasColor (1)
    • isRegionOf (1)
    • hasGeometry (1)
    • hasComment (1-n)

There are some DSP base properties that are used directly in the above resource classes. Some of them can also be subclassed and used in a resource class.

  • hasLinkTo: a link to another resource
  • hasColor: Defines a color value.
  • hasComment: Defines a standard comment.
  • hasGeometry: Defines a geometry value (a JSON describing a polygon, circle or rectangle).
    • must be used directly in the XML data file in the <region> tag
  • isRegionOf: A special variant of hasLinkTo. It means that the given resource class is a region of interest in an image.
    • must be used directly in the XML data file in the <region> tag
  • isAnnotationOf: A special variant of hasLinkTo. It means that the given resource class is an annotation to another resource class.
Last update: June 9, 2023