linkml-activitypub

LinkML representation of ActivityStreams and ActivityPub schema

https://pypi.org/projects/linkml-activitypub

Source schema:

• linkml_activitypub/activitystreams.yaml - ActivityStreams2 vocabulary schema
• linkml_activitypub/activitypub.yaml - ActivityPub Extensions to ActivityStreams2 (imports ActivityStreams2)

Generated models:

• generated/ - All generated schema for both source schema
• Pydantic 2 Models:
  • linkml_activitypub/activitystreams.py
  • linkml_activitypub/activitypub.py
• Dataclasses
  • linkml_activitypub/dataclass/activitystreams.py
  • linkml_activitypub/dataclass/activitypub.py

ActivityStreams

Process

Intermediate files are in the data directory

• activitystreams2.owl - Initially imported from activitystreams2.owl
  • Removed problematic OrderedCollection definitions
• activitystreams2.ofn - Convert to functional notation with robot
• activitystreams2.yaml - Then to rough linkml using schema-automator

Then the final schema in linkml_activitypub/activitystreams.yaml:

• Reorder to match ActivityStreams
• Ensure correct
  • inheritance
  • multivalued
• Prune extra properties and classes to match those in ActivityStreams2 normative definition
  • Then re-add the ones that declare a class in their domain, even if the class doesn't list that property in its definition
  • Except for those types that seem to be metaclasses:
    • attributedTo (-> actor)
• Added LinkML properties (where needed):
  • Classes
    • disjoint_with
    • see_also when references given
  • Properties
    • description
    • domain
    • range
    • minumum_value
    • maximum_value
• Added missing slots
  • closed
  • startIndex
• Handle special property cases
  • items is marked as list_elements_ordered: true on OrderedCollection and false on Collection
• Made types
  • anyURI as xsd:anyURI, did not try and find a validator pattern. The spec alternatingly uses its own anyURI prop and xsd:anyURI
  • duration as a string that indicates it's a xsd:duration, finding a pattern is TODO
• Made enums
  • unitEnum - for unit
• Copied Notes to class description rather than comments
• Added schema prefixes:
  • schema: https://schema.org/ - for specifying IETF BCP 47 language codes

Errata

• OrderedCollectionPage is not a subclass of, and doesn't mix in CollectionPage since it would then have an ambiguous class definition, since OrderedCollection inherits from Collection but asserts that the list_items_ordered slot is true rather than false. Instead, the slots from CollectionPage are just duplicated.
  • Accordingly, the domain and range of slots that include CollectionPage also include `OrderedCollectionPage
• Need to implement some xsd:duration pattern

TODO

• JSON-LD Serialization: https://www.w3.org/TR/activitystreams-core/#syntaxconventions
• Collection serialization: "In the JSON serialization, the unordered items of a Collection are represented using the items property while ordered items are represented using the orderedItems property."
  • Should items and orderedItems just be disjoint slots, rather than a slot with a special property modification?

ActivityPub

Process

Errata

TODO

• Everything!

References

• Status of AS OWL vocabulary and etc. https://github.com/w3c/activitystreams/issues/416

See Also

• https://github.com/steve-bate/activitypub-ontology