[SOLVED] Can't update item

Hi There,

I’m fighting with a problem that I don’t understand. Added a lot of debug code, but it won’t work.

// presence.items
Switch Presence "Anwesenheit" <presence> (gHome)

// presence.rules
rule "Presence Control - Set Presence"
  Member of gPresenceControl changed
  var presence_state = gPresenceControl.members.map[state].reduce[ result, v | 
    if (v == ON) {
      return ON
    } else {
      if (result == ON) {
        return ON
      } else {
        return OFF

  if (presence_state == ON) {
  } else if (presence_state == OFF) {
  } else {
    logInfo("Develop","Something Else")

  if (Presence.state == presence_state) return;

The result of this rule is the following exception:

2018-11-01 11:42:12.889 [ERROR] [ntime.internal.engine.RuleEngineImpl] - Rule 'Presence Control - Set Presence': An error occurred during the script execution: Could not invoke method: org.eclipse.smarthome.model.script.actions.BusEvent.sendCommand(org.eclipse.smarthome.core.items.Item,java.lang.String) on instance: null

But when changing Presence.sendCommand(presence_state) to Presence.sendCommand(ON) it works.

Any ideas, what went wrong here?


Try that, the parser/Compiler may a hard time with the type of presence_state

1 Like

Have you considered using triggeringItem ?

Thx @vzorglub: This solves the problem.

Please mark the thread as solved, thanks

I’m not sure if it meets your specific requirements, but there is a generic approach to presence detection.

I think you are trying to see if any member of gPresenceControl is ON, correct? If so then you need no code at all and can use

Group:Switch:AND(OFF,ON) gPresenceControl

That will set the state of gPresenceControl to OFF is ALL of its members are OFF and ON if any one of them is not OFF.

Then your Rule completely goes away and you can just use gPresenceControl in place of Presence everywhere.

If you want to do some other logic, such as waiting before setting Presence to OFF just in case you, for example, go check the main and are only away for a few minutes, see the link above.

And for completeness, better ways to find out if there are any members of gPresenceControl that are ON without relying on the Group would be

val presence_state = if(gPresenceControl.members.filter[ s | s.state == ON ].size > 0) ON else OFF

I believe a cleaner way to do it using map/reduce would be

val presence_state = gPresenceControl.members.map[state].reduce[ result, v | 
    if(result == ON) ON
    else if(v == ON) ON
    else OFF

But the one liner filter is more appropriate and the ability to eliminate the Rule entirely is even better.

This is kind of related to the other thread we had as well. The Rules DSL is differently structured and there is a whole lot that it looks like you are trying to do in Rules that don’t have to be done in Rules if you use Groups.

1 Like

The Group Switch did the job for me. THX

Please mark the thread as solved, thanks. Tick the post that gave you the solution.
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