Change state type on MQTT payload from boolean to string

[snakuzzo]

Is your feature request related to a problem? Please describe

According to Home Assistant documentation about MQTT Binary Sensor entities (HERE), Z2M publish states as boolean and not as string

This is the message published on MQTT broker...

zigbee2mqtt/mywindow {"battery":97,"contact":true,"linkquality":72,"temperature":24,"voltage":2995}

...and this is my binary_sensor...

binary_sensor:

  - platform: "mqtt"
    name: "mywindow"
    state_topic: "zigbee2mqtt/mywindow"
    availability_topic: "zigbee2mqtt/bridge/state"
    value_template: "{{ value_json.contact }}"
    payload_on: false
    payload_off: true
    device_class: "window"

Take a look at keesschollaart81/vscode-home-assistant#1148

Describe the solution you'd like

Publish states true and false as string in MQTT payload

Describe alternatives you've considered

...apply template on HA ?
I think it is necessary to update the documentation related to manual configurations, applying the templates

  - platform: "mqtt"
    name: "mywindow"
    state_topic: "zigbee2mqtt/mywindow"
    availability_topic: "zigbee2mqtt/bridge/state"
    value_template: "{{ 'true' if value_json.contact == true else 'false' }}"
    payload_on: "false"
    payload_off: "true"
    device_class: "window"

Additional context

[Koenkk]

IMHO properties like contact should definitely be true/false and not "true"/"false".

The question is whether this prevents the Home Assistant sensor for working (which I don't think is the case), can you confirm this?

[snakuzzo]

I agree with you. IMHO it's correct using boolean and not strings, but HA devs made the choice to use strings.
Anyway...sensors configured with booleans work fine...no warnings or errors. To bypass the HA helper warnings on VSCode and to comply with the HA guidelines I used template described above in "Describe alternatives you've considered" section