res-protocol-v1.1-update.md

RES Protocol v1.1 Update

Changes from v1.0

The update only affects Model change event.

The specification has been updated to have the changed properties contained in a values field:

v1.0 model change event payload:

{
   "foo": "bar",
   "faz": 42
}

v1.1 model change event payload:

{
   "values": {
      "foo": "bar",
      "faz": 42
   }
}

Reason

Model change events, as defined in RES-service specification V1.0, gave no room to include meta data in the event. This is a design flaw which prevents the specification to adapt to requests such as version numbering of resources.

Impact

The version upgrade only affect services. The RES-client protocol, and subsequently any RES client, is unaffected.

Resgate can detect service legacy (v1.0) behavior and handle it, but will log a Deprecated warning with a link to this page.

The only time a legacy service might be mistakenly taken as non-legacy (v1.1), is for the following two change event payloads:

{
    "values": { "rid": "example.model" }
}

or

{
   "values": { "action": "delete" }
}

Migration

Any service that sends model change event should be updated to follow v1.1 specification.

This can be done in partial steps, one service at a time, as Resgate detects legacy behavior for each separate model change event.