Issue with assigning a value to a String Item: Cannot assign a value in null context

Setup, Configuration and Use Scripts & Rules
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1

Hi guys,

I got a strange behaviour with a String-Item in a file-based rule, and its driving me nuts.
Every time I try to assign a value to this Item, I get a Error-message, which says, that the item is NULL, and I cannot assign a value to it.

Item Definition

String securityTriggerItem "State [%s]"  {expire= "120m, command=NONE"}

Rule definition
…
sendCommand(securityTriggerItem, “trigger”)
…
The result is a NullPointerException.

When trying to create a new String-Object, the Error is the following:
…
securityTriggerItem = new String ()
…

results in:
…
An error occurred during the script execution: Cannot assign a value in null context.
…

There are no overlapping events, and it is also not during startup of OH, as suggested in other posts.

If anyone has an idea, I would be really grateful.

  • Platform information: Openhab 3.3.0 (Dockerized)
  • openHAB version: 3.3.0
2

I think the problem is in the

command=NONE

part.
Instead try e.g.
String securityTriggerItem "State [%s]" {expire= "120m, state=''"}

3

As per my understanding the send ommand function is expecting the item name as string:

sendCommand("securityTriggerItem","trigger")
4

The approach to pass a String as first parameter actually worked.
A quick check in my other code revealed, that I always used the Item-name itself as parameter, which also worked fine.
Not sure why a String-Item requires special treatment here.

Thank you for your support, I thought I’m going crazy.

5

Within a DSL rule you should also be able to do

securityTriggerItem.sendCommand("trigger")

If that’s more convenient for you

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