Functions and Actions as Interfaces

[ralfhandl]

I would like to define an OData function or action outside of a service that serves as an interface. Such a function/action could then be invoked by a special client whenever a service implements it.

The functions isancestor and isdescendant defined in the Aggregation vocabulary would have been candidates for such treatment, if we had not assumed they are implemented by every service that uses the Aggregation.RecursiveHierarchy annotation.

If the interface has a parameter or return type of an abstract type like Edm.EntityType, its implementations MAY (or MUST) replace this with a concrete entity type.

Proposal

[https://github.com/oasis-tcs/odata-vocabularies/pull/228]

The proposed annotation

"ActionA": [{
  "$Kind": "Action",
  "@Core.ImplementsSignature": "ActionB"
}]

is not superior to currently used annotations like

"EntityType": {
  "$Kind": "EntityType",
  "@SAP.ActionB": "ActionA"
}

Therefore close this issue without further action.

Imported from ODATA-1600