Profile to cycle through a list of values upon event trigger

Add-ons Other
1

All,

After a smooth upgrade to OpenHAB 4.2 I just discovered the Basic Profiles transformations bundle. It seems that I can get rid of several one-line rules, e.g. just toggling a switch item when a button was pressed.

I have some use cases though where I have a list of fixed values for a (say) String item and upon every press of a button (triggers an event) I assign the next value from the list to that String item.
At the moment I implemented this as a rule, like this:

switch (receivedEvent) {
  ...
  case "3001": {
    // Long press "Light" button
    switch (vSetLightConfig_Kitchen.state.toString) {
        case "NORMAL": { vSetLightConfig_Kitchen.sendCommand("REDUCED") }
        case "REDUCED": { vSetLightConfig_Kitchen.sendCommand("EVENING") }
        case "EVENING": { vSetLightConfig_Kitchen.sendCommand("NIGHT") }
        case "NIGHT": { vSetLightConfig_Kitchen.sendCommand("NORMAL") }
        default:  { vSetLightConfig_Kitchen.sendCommand("NORMAL") }
      }
  }
  ...
}

I wonder if it would be possible (and useful) to have this kind of logic covered by a (new) transformation profile. (Using a MAP transformation would certainly be another way to get rid of the coded rule…)

Thanks,
Dietmar

2

Map transformation would probably be the most straight forward.

Beyond that you could implement your rule as a Script transformation but you aren’t really saving anything. Same amount of code.Same amount of resources. It’s just somewhere else, not in rules.

3

Thanks for your feedback!

Yes, MAP transformation is better than hard coded switch statement, but still it can be triggered only from a rule/script.

My original question was triggered (sic!) by this statement in Transformations / Profiles | openHAB

Trigger profiles are powerful means to implement some immediate, straight-forward logic without the need to write any rules.

Never mind…

Regards,
Dietmar

4

Says who? You can use the Map transformation in a transform profile. If the binding supports it, you can use it in the Channel config.

Those are developer’s docs, not end user docs. But the transform profile is a trigger profile. And the transform profile can use any installed transformation add-on including the Map transform.

5

I’ve just opened a PR to support creating a trigger profile in JRuby. (State profiles are already supported).

Once it’s merged, you can create your own trigger profile and use it like this:

String vSetLightConfig_Kitchen {channel="mqtt:topic:test:test" [ profile="ruby:trigger_button_cycle", event="3001", values="NORMAL,REDUCED,EVENING,NIGHT" ], channel="otherchannel...."}

To create the profile in JRuby:

# frozen_string_literal: true

profile(:trigger_button_cycle) do |event, trigger:, item:, configuration:|
  if event == :trigger_from_handler && (configuration["event"].nil? || configuration["event"] == trigger)
    next unless (values = configuration["values"])

    values = values.split(",").map(&:strip).compact
    current = values.index(item.state.to_s) || -1
    new_value = values[current + 1] || values.first

    item.command new_value
  end
end

Essentially, this lets you create whatever profile you want to do whatever you wish, without needing to wait for someone else to come along and create a profile / addon for you. You can whip one up quickly using a jruby script.

PS The above ruby profile is only usable in file-based .items file. If you want to use it on UI based items, simply add a label and config description, e.g.:

# frozen_string_literal: true

config_description = config_description do
  parameter :event, :text, label: "Trigger Event",
                           description: "React when this event occurs. When not supplied, react to any event."
  parameter :values, :text, label: "Values", description: "A comma separated list of values to cycle through"
end

profile(:trigger_button_cycler,
        type: :trigger,
        label: "Cycle through states on trigger",
        config_description:) do |event, trigger:, item:, configuration:|
  if event == :trigger_from_handler && (configuration["event"].nil? || configuration["event"] == trigger)
    next unless (values = configuration["values"])

    values = values.split(",").map(&:strip).compact
    current = values.index(item.state.to_s) || -1
    new_value = values[current + 1] || values.first

    item.command new_value
  end
end

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6

PR merged and released

1 Like
7

Yor are right, and my statement about “can be triggered only from a rule/script” was certainly misleading.

What I meant to say: Using MainUI I was not able to link an event channel to a string item using a MAP profile, the only profile choice is “Trigger Event String”.

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Therefore my conclusion was that I still need a rule to determine the new item state with a MAP transformation.

8

Awesome!