[SOLVED] Rule 'Extractor Fan sensor changed': null - another case

I forgot about that problem. Indeed it could still be an issue.

There are ways to avoid it though.

  • use the Image registry to get the Item instead of filtering on a group. See Design Pattern: Associated Items for an example.

  • use changed triggers instead of received update where possible

  • try to avoid having a rule that triggers really fast if you can help it, sometimes this requires totally restructuring your approach though.

Actually in Python at least, you really need to access the Group in the way. For example, in the Rule above, you’d just pull the Item states it of items[“itemName”] and never touch the Group as it’s changing. So there is no access to the Group’s members while it’s changing through the Group Item and no error.