Imitating the Power Consumption of Lights (and others)

[rlkoshak (Rich Koshak)]

I think it still qualifies as a Design Pattern, but I’ll write it more like a tutorial than just an example.

I’ve already written most of it up in my own notes. I’ve transcribed it and beefed it up a bit here:

Design Pattern: Working with Groups in Rules

Edit: Updates for OH 4, inclusion of JS Scripting and Blockly examples, removed the doors example as it’s superfluous. Please see https://community.openhab.org/t/design-pattern-what-is-a-design-pattern-and-how-do-i-use-them/40319 for how to read and use DPs. Problem Statement One powerful way to consolidate code in rules is to use array/list manipulation operations on the members of a Group. For example, filter down to just those members that are ON, get a list of the labels of those Items tha…

It ended up being difficult to provide a step by step guide as the steps are just:

1. add your Items to groups
2. trigger the rule on all Items (or Group updates if multiple execs of the rule per event isn’t a problem)
3. pull the triggering Item from the Group based on lastUpdate
4. code as usual

However, I did provide examples for and description of what all of the MyGroup.members.* methods do (at least all the ones I know) including map/reduce.