Multiplexing with WebSocket

[sebastiankb]

This problem is a placeholder that takes care of multiplexing with WebSockets.

So far node-wot consumer cannot distinguish between different events via WebSocket.

[6d77]

Proposal:

• Provide a data schema for each of the possible events including possible constant values for distinguishing elements
• When a message arrives over websocket, perform schema validation against each of the possible event data schemata
• Forward the message only to the event with the matching data schema

[egekorkan]

A Data Schema based forwarding would be problematic when the Data Schemas are the same for multiple events. It is sadly quite common that people do not describe the payload detailed enough and simply say "type":"string" for all of them...

[egekorkan]

I think for anything over WebSocket, there has to be a subprotocol where the event data is always encapsulated with the interaction name and the type of the data, like event-data, event-unsubscription-output, action-output etc.

[6d77]

We should look on some real-world examples. @sebastiankb , @wiresio could you provide something?

[egekorkan]

One real-world example is the Mozilla WebThing Websocket API: https://iot.mozilla.org/wot/#web-thing-websocket-api