Kudo for YAMLcomposer: Indicator and zigbee lights creation of items, groups, etc

Max_G · August 13, 2026, 12:00pm

This add-on “YAMLcomposer” rocks, at least for my use cases

I only came across it when reading Reimplement my Sitemap (>1000 Items) to WebUI using the yamlcomposer and yaml based widget templates .

At first, and I repeat my commentary here:

The first use case was creating things, items and groups (~50 per battery) for my five 5kWh 48V LiFePO4 batteries connected to my inverter.charger. So far so good…

Then I thought I could realise an indicator light ==> a RGB LED in each room (integrated into a central light fixture) indicates a few events around the house; e.g., when mail has been delivered, the gate is opened, irrigation is running, tank is filling; each with a different colour.

While I have only one dummy light to prototype, YAMLcomposer was ideal in creating the items and groups for it.

version: 1

# Indicator causes are independent state Items. A source rule owns each cause;
# indicator.rules is the only component allowed to control the indicator lights.
items:
  grp_Indicator_Causes:
    type: Group
    label: Indicator causes

  grp_Indicator_Red:
    type: Group
    label: Red indicator causes

  grp_Indicator_Orange:
    type: Group
    label: Orange indicator causes

  grp_Indicator_Green:
    type: Group
    label: Green indicator causes

  grp_Indicator_Blue:
    type: Group
    label: Blue indicator causes

  grp_Indicator_Yellow:
    type: Group
    label: Yellow indicator causes

  grp_Indicator_Purple:
    type: Group
    label: Purple indicator causes

  grp_Indicator_Lights_Power:
    type: Group
    group:
      type: Switch
    label: Indicator lights power

  grp_Indicator_Lights_Colour:
    type: Group
    group:
      type: Color
    label: Indicator lights colour

  grp_Indicator_Lights_Online:
    type: Group
    group:
      type: Switch
    label: Indicator lights online

  Indicator_Cause_SmartPlugAlert:
    type: Switch
    label: Smart-plug fault
    groups: ["grp_Indicator_Causes", "grp_Indicator_Red"]

  Indicator_Cause_IrrigationRunning:
    type: Switch
    label: Irrigation running
    groups: ["grp_Indicator_Causes", "grp_Indicator_Green"]

  Indicator_Cause_TankFilling:
    type: Switch
    label: Tank filling
    groups: ["grp_Indicator_Causes", "grp_Indicator_Blue"]

  Indicator_Cause_MailWaiting:
    type: Switch
    label: Mail waiting
    groups: ["grp_Indicator_Causes", "grp_Indicator_Yellow"]

  Indicator_Cause_Doorbell:
    type: Switch
    label: Doorbell
    groups: ["grp_Indicator_Causes", "grp_Indicator_Yellow"]

  Indicator_Cause_GateEvent:
    type: Switch
    label: Gate event
    groups: ["grp_Indicator_Causes", "grp_Indicator_Yellow"]

  Indicator_Cause_GateOpen:
    type: Switch
    label: Gate open
    groups: ["grp_Indicator_Causes", "grp_Indicator_Yellow"]

  Indicator_Cause_WashingMachineRunning:
    type: Switch
    label: Washing machine running
    groups: ["grp_Indicator_Causes", "grp_Indicator_Purple"]

  Indicator_ActiveCause:
    type: String
    label: Indicator active cause

  Indicator_ActiveColour:
    type: String
    label: Indicator active colour

Now this is not even the thing that thrilled me; I initially created the items and groups referenced to a location (shed_indicator); yet later realised it should have been location-less (indicator). Instead of using the UI and delete and recreate the items and groups, I created a new .yaml file with the location reference removed; deleted the old .yaml, saved the new; change the item/group names in my text-based rule files, and made a change that could easily have taken 2 hours in less than 15 minutes.

As said I elsewhere: kudo to @jimtng for creating this add-on. I love it (and I am not even a yaml guy)

jimtng · August 13, 2026, 12:06pm

Nothing in your posted yaml content actually needs YAML Composer. It’s a standard openhab YAML config.

Max_G · August 13, 2026, 12:20pm

Standard OH config; I need to check this out!

Well, point taken; lets give it a YAMLcomposer example then (see,I said I am not a YAML guy; never used it in context with openHAB).

The battery set-up here is a YAMLcomposer example

This is another composer example; creating LEDs…

variables:
  group_prefix: grp_${item_prefix}
  power_groups: []
  colour_groups: []
  online_groups: []

things:
  mqtt:topic:mosquitto:${package_id}:
    bridge: mqtt:broker:mosquitto
    label: ${thing_label}
    location: ${location}

    channels:
      online:
        type: switch
        label: Online
        config:
          stateTopic: ${topic_base}/availability
          transformationPattern:
            - JSONPATH:$.state
          "on": online
          "off": offline

      power:
        type: switch
        label: Power
        config:
          stateTopic: ${topic_base}/state
          commandTopic: ${topic_base}/set/state

      brightness:
        type: dimmer
        label: Brightness
        config:
          stateTopic: ${topic_base}/brightness
          commandTopic: ${topic_base}/set
          transformationPattern:
            - JS:light_brightness_in.js
          transformationPatternOut:
            - JS:light_brightness_out.js
          formatBeforePublish: '{"brightness":%s,"transition":3}'
          min: 0
          max: 100

      colour:
        type: color
        label: Colour
        config:
          colorMode: XYY
          stateTopic: ${topic_base}
          commandTopic: ${topic_base}/set
          transformationPattern:
            - JS:light_xyy_in.js
          transformationPatternOut:
            - JS:light_xyy_out.js

      colour_temperature:
        type: dimmer
        label: Colour temperature
        config:
          stateTopic: ${topic_base}/color_temp
          commandTopic: ${topic_base}/set
          transformationPattern:
            - JS:light_temp_in.js
          transformationPatternOut:
            - JS:light_temp_out.js
          formatBeforePublish: '{"color_temp":%s,"transition":3}'
          min: 0
          max: 100

      colour_mode:
        type: string
        label: Colour mode
        config:
          stateTopic: ${topic_base}/color_mode

      link_quality:
        type: number
        label: Link quality
        config:
          stateTopic: ${topic_base}/linkquality
          min: 0
          max: 255

      command:
        type: string
        label: Combined JSON command
        config:
          commandTopic: ${topic_base}/set

items:
  ${group_prefix}:
    type: Group
    label: ${thing_label}

  ${item_prefix}_Power:
    type: Switch
    label: ${thing_label} power
    icon: switch
    groups: "${[group_prefix] + power_groups}"
    channel: mqtt:topic:mosquitto:${package_id}:power

  ${item_prefix}_Brightness:
    type: Dimmer
    label: ${thing_label} brightness
    icon: light
    groups: ["${group_prefix}"]
    channel: mqtt:topic:mosquitto:${package_id}:brightness

  ${item_prefix}_Colour:
    type: Color
    label: ${thing_label} colour
    icon: colorwheel
    groups: "${[group_prefix] + colour_groups}"
    channel: mqtt:topic:mosquitto:${package_id}:colour

  ${item_prefix}_ColourTemperature:
    type: Dimmer
    label: ${thing_label} colour temperature
    icon: colorwheel
    groups: ["${group_prefix}"]
    channel: mqtt:topic:mosquitto:${package_id}:colour_temperature

  ${item_prefix}_Online:
    type: Switch
    label: ${thing_label} online
    icon: network
    groups: "${[group_prefix] + online_groups}"
    channel: mqtt:topic:mosquitto:${package_id}:online

  ${item_prefix}_ColourMode:
    type: String
    label: ${thing_label} colour mode
    groups: ["${group_prefix}"]
    channel: mqtt:topic:mosquitto:${package_id}:colour_mode

  ${item_prefix}_LinkQuality:
    type: Number
    label: ${thing_label} link quality
    icon: network
    groups: ["${group_prefix}"]
    channel: mqtt:topic:mosquitto:${package_id}:link_quality

  ${item_prefix}_Command:
    type: String
    label: ${thing_label} combined command
    groups: ["${group_prefix}"]
    channel: mqtt:topic:mosquitto:${package_id}:command

version: 1

packages:
  house_led_001: !include
    file: $pkg/zigbee-rgbcct-light.inc.yaml
    vars:
      topic_base: ArgyleCourt/House/LED_001
      item_prefix: House_LED_001
      thing_label: House LED 001
      location: House

  house_led_002: !include
    file: $pkg/zigbee-rgbcct-light.inc.yaml
    vars:
      topic_base: ArgyleCourt/House/LED_002
      item_prefix: House_LED_002
      thing_label: House LED 002
      location: House

  # ...through House_LED_050

I don’t know though if there is a loop or range [1..50] option.

jimtng · August 13, 2026, 12:29pm

I’ve just started working on this!

jimtng · August 16, 2026, 9:47am

github.com/openhab/openhab-addons

[yamlcomposer] Add Loop support (`!for`) and enhance Conditionals (#21408)

main ← jimtng:yamlcomposer-loops

opened 09:21AM - 16 Aug 26 UTC

jimtng

+6380 -3320

## Summary This PR introduces several significant enhancements to the YAML Comp…oser, focusing on dynamic content generation, improved conditional logic, and expanded expression support. ## Key Features - **Loop Support (`!for`):** Add a new directive that allows for dynamic sequence iteration and templating within YAML definitions. - **Key-Level `!if`:** Introduce a shorthand form for the `!if` tag to streamline conditional blocks and improve readability. - **Range Expressions:** Add support for Jinjava `range()` functions and Ruby-style range syntax (`[1..5]` for inclusive and `[1...5]` for exclusive ranges). - **Enumerate Support:** Add `enumerate` as both a filter and a function, supporting list and map iteration with `.key` and `.value` accessors. ## Internal Changes - **Directive Processing Phase:** Introduce a dedicated directive processing phase to the composer's transformation pipeline. This provides a more robust framework for handling structural tags like `!for` and `!if`. - **Test Suite Reorganization:** The existing test suite has been split into multiple specialized files. This reorganization improves maintainability and makes it easier to navigate the growing number of test cases.

The detailed doc for loops:

github.com/jimtng/openhab-addons

bundles/org.openhab.io.yamlcomposer/doc/loops.md

3c50d2bce

# Loops (`!for`)

The `!for` tag performs configuration unrolling and iteration during the **preprocessing phase**.

> **Note:** Iterations are evaluated **once** when the YAML file is loaded.
> These are not runtime rules.
> They do not react to live state changes in openHAB.

[[toc]]

## When to Use `!for`

Use the `!for` tag to dynamically generate repetitive openHAB configuration structures based on the **Resolution Context** (variables defined in the file, injected via `!include` or `!insert`, or [environment globals](variables.md#env-to-access-environment-variables)).

Typical use cases in openHAB:

- **Generate multiple Things** from a list of device IDs.
- **Generate multiple Channels** from structured metadata.
- **Generate multiple Items** from a list, map, or equipment definition.
- **Generate semantic model structures** (rooms, equipment, points).

This file has been truncated. show original

Notably: I haven’t added a break or continue because I don’t think they’re necessary for the case of building a YAML output. If you can think of a reason why they are important to have, please let me know. Currently if you must, you could use several alternatives: using for filtering, or using if inside the loop.

jimtng · August 16, 2026, 1:46pm

I’ve updated the PR description to show an example of the loop and the new if/elseif/else syntax.

The old if syntaxes are still supported. They actually serve as a value replacement, so they are still useful.

A summary of the if syntaxes.