Dynamically change mapping between thing and item?

[rlkoshak (Rich Koshak)]

@fmeili1

Maybe I can make all existing items to virtual items and create a rule to feed these virtual items to do the mapping in the rule.

That’s one approach and it might be the least likely to feed some values to the wrong Item during the transition.

@fmeili1

But for that I need to map the 102 existing things to one special item which may trigger the rule on any change (I think this is not possible in OH?).

Yes, you can use wild card subscriptions. For example foo/bar/# will subscribe to all message to all topics under foo/bar.

@fmeili1

An other possibility would be to get completely rid of the existing things and do an “raw” MQTT subscribe (I think this is possible in OH) in a rule to all inverter messages to do the dynamic mapping in a rule.

This would be done by creating an event Channel on an MQTT Thing or even on the MQTT Bridge with a wild card subscription like described above. That Channel can directly trigger a rule. See MQTT Event Bus [4.0.0.0;5.9.9.9] for an example.

@fmeili1

I don’t know if one of the OH transformation mechanisms may help in this situation?

Probably not.

@fmeili1

Any ideas how to achieve this in a nice way?

I worry that with this approach though there will be a brief period between when the change is detected and all the Items are relinked where updates will go to the wrong Items. Maybe the updates don’t come in that fast after the change is detected?