Error in rule: 'getChannel' is not a member of 'java.lang.String'

Lukie · January 21, 2021, 12:01pm

In OH2, I was able to do this:

val trigger = receivedEvent.getChannel().toString()

In OH3, only val trigger = receivedEvent works and this rightly gives me the event START, but I am after the channel that triggered the event. I have unsuccessfully tried the below variations but from reading the release notes I wonder if it has been removed.

receivedEvent.getChannel()
receivedEvent.channel

I initially had this as 2 rules but combined them into one. I suppose I could go back to that, but just checking I am not missing something.

rule "Sunset Rule"
	when
		Channel "astro:sun:home:civilDusk#event" triggered START or
		Channel "astro:sun:minus45:civilDusk#event" triggered START or
		Channel "astro:sun:test:civilDusk#event" triggered START
	then
		val trigger = receivedEvent.getChannel().toString()
		logInfo("Crib","Dusk is approaching - Turning on lights. Triggering item is " + trigger)
		switch trigger {
			case "astro:sun:minus45:civilDusk#event" : {
				logInfo("Crib","Turning on inside lamps")
				Lounge_Lamp_Switch.sendCommand(ON)
				Upstairs_Lounge_Lamp_Switch.sendCommand(ON)
				Christmas_Tree_Lights.sendCommand(ON)
				sendNotification("xxx","Dusk - Turning on inside lamps")
			}
			case "astro:sun:home:civilDusk#event" : {
				logInfo("Crib","Turning on front lights")
				Lights_Front_Switch_1.sendCommand(ON)
				sendNotification("xxx","Dusk - Turning on outside lights")
			}
		}
end

rossko57 · January 21, 2021, 2:32pm

Yes, it’s just a string now (so of course no .getChannel() method)

What you need is a new implicit variable like triggeringChannel or something, but I don’t know if they have made that available in DSL rules.
The problem got mentioned but unanswered in a related issue

github.com/openhab/openhab-core

Comment by ccutrer - [automation] Provide triggering item name in the rule context

openhab:master ← kaikreuzer:triggeringItem

Sorry to comment directly on the code first without reading the thread. It sound…s like it's on purpose that receivedEvent now returns a string with the value of the event, instead of the event object itself. But the documentation update didn't actually happen (https://github.com/openhab/openhab-distro/wiki/Breaking-Changes-in-openHAB-3#rules doesn't mention it), and I doubt the examples have been updated either. Critically, it is now no longer possible to access which channel triggered an event if a rule is set up to handle multiple triggers at the same time. Maybe a new implicit variable should be added for this case, such as `triggeringChannelName`?

I think you may need to log an issue for this enhancement/regression.

morph166955 · January 21, 2021, 2:57pm

Can you not just use something like:

import org.openhab.core.model.script.ScriptServiceUtil
ScriptServiceUtil.getItemRegistry.getItem(triggeringItemName)

And then work off of that?

rossko57 · January 21, 2021, 7:48pm

Not really, these are event channels not Items.

Lukie · January 22, 2021, 2:34am

Done:

Thanks @rossko57

morph166955 · January 23, 2021, 4:08pm

Could you not just tie an item to the channel and monitor that for the update instead?

rossko57 · January 23, 2021, 4:27pm

Only if the binding offers some state channel that is vaguely similar to the event you are looking for.
State channels, the more common type that we link to Items, and event channels, also called trigger channels, are two different things.

In the particular case of Astro here, there is a state channel for e.g. sunrise. But it gets set to 0730 or whatever at midnight, when astro calculates the day ahead. It doesn’t change at 0730.