Adding Data Mapping per Thing #1411
Description
As a possible helper for #1409 , we can think of an additional arguement in consume() where a "value path" is given. In EdiTDor project we are working on a new PR at eclipse/editdor#136 where a json path can be given for the values to be stripped out of a JSON object. So if the Thing (here the gateway) sends {value:123, id:abcd, timestamp:2024} we can put /value where only 123 will be presented to the UI. The other parameters are like header information (telemetry) that are inserted by the gateway that are not relevant for the application, so the TD should not have an object.
This is basically out of band data mapping where having this in the TD 2.0 would remove the need for the implicit knowledge. This is the same thing with Webthings and other such solutions. Allowing a new parameter like this as an argument for the consume() method would allow settings this for the entire Thing and can help with OPCUA content type issue too. Application of this value path should happen after content serdes but before passing to the validation.