Operation Delegation

An operation is a specific type of submodel element capable of performing server-side functions. However, in certain environments, this is not possible. Therefore, the operation can be delegated to an independent destination (such as an HTTP URL) to be executed. An example request body is given below.

[
    {
        "value": {
            "modelType": "Property",
            "value": "5",
            "valueType": "xs:int",
            "idShort": "int"
        }
    }
]

To create an operation delegation, a Submodel that has an Operation(-SubmodelElement) must be present:

• To achieve the delegation functionality, a Qualifier of type “invocationDelegation” is added to the operation.

• As a value, the connection information (such as an HTTP URL) to the desired operation must be given.

This means that operations can be delegated to endpoints of the same server as well as to external servers. For the front-end, it remains completely transparent whether an operation was called directly or delegated.

The destination for the delegated request must support the request with OperationVariable[] as parameter. It should also return the output as OperationVariable[].

As of now, only delegation to HTTP URLs is supported.