The "equals" condition does not work for the items storing dimensionless number values

[mak-42]

I created the channel like this and linked it to the item "AqaraSmartHomeCube001_Side".

  - id: side
    channelTypeUID: mqtt:number
    label: Side
    description: null
    configuration:
      min: 0
      stateTopic: zigbee2mqtt/AqaraSmartHomeCube001
      transformationPattern: JSONPATH:$.side
      max: 6

I added the "But only if" condition to the rule like this:

conditions:
  - inputs: {}
    id: "4"
    configuration:
      itemName: AqaraSmartHomeCube001_Side
      state: "0"
      operator: "="
    type: core.ItemStateCondition

This condition always returns "false" even state of "AqaraSmartHomeCube001_Side" is equal to 0.

The problem is in the "org.openhab.core.automation.internal.module.handler.ItemStateConditionHandler". Look at the code (version 3.1.x, but i bet the version 3.2 has the same issue):

            Item item = itemRegistry.getItem(itemName);
            State compareState = TypeParser.parseState(item.getAcceptedDataTypes(), state);
            State itemState = item.getState();
            DecimalType decimalState = itemState.as(DecimalType.class);
            logger.debug("ItemStateCondition '{}'checking if {} (State={}) {} {}", module.getId(), itemName, itemState,
                    operator, compareState);
            switch (operator) {
                case "=":
                    logger.debug("ConditionSatisfied --> {}", itemState.equals(compareState));
                    return itemState.equals(compareState);

The "item.getAcceptedDataTypes()" returns "[class org.openhab.core.library.types.DecimalType, class org.openhab.core.library.types.QuantityType, class org.openhab.core.types.UnDefType]". It means the "TypeParser.parseState(item.getAcceptedDataTypes(), state)" returns object of "DecimalType" creating as "DecimalType.valueOf("0")". But the "item.getState()" returns the object of "QuantityType". The "compareState" and "itemState" have different types. and the equation "temState.equals(compareState)" never returns "true".

The safest way to solve it to rewrite the equation like this:

return (null != decimalState && compareState instanceof DecimalType && decimalState .equals((DecimalType)compareState)) ||  itemState.equals(compareState);

But I think the right path to fix it is to convert the "itemState" to the class of "compareState" before comparing.

I have found a workaround. The condition can be replaced by this couple which works well:

conditions:
  - inputs: {}
    id: "5"
    configuration:
      itemName: AqaraSmartHomeCube001_Side
      state: "0"
      operator: ">="
    type: core.ItemStateCondition
  - inputs: {}
    id: "4"
    configuration:
      itemName: AqaraSmartHomeCube001_Side
      state: "0"
      operator: <=
    type: core.ItemStateCondition

[cweitkamp]

I submitted #2653 to solve this. I will allow equals comparison between DecimalTypes and QuantityTypes but will log a warning to use QuantityType in the condition too if the state is a QuantityType.

[cweitkamp]

I will allow equals comparison between DecimalTypes and QuantityTypes but will log a warning to use QuantityType in the condition too if the state is a QuantityType.

I have to revoke this. We decided in #2653 that we cannot set a DecimalType value of 5 equals to a QuantityType of 5 °C or 5 °F. In the future there will be a warning if the item state has a unit but the comparison value is specified without a unit.

[mak-42]

But what is the solution for the described situation? The item's status is a dimensionless number (a current side number of the cube). What should I write in conditions section instead of "0"?

[cweitkamp]

Just to make sure - your item state is a dimensionless QuantityType without a unit (internally AbstractUnit.ONE)?

For the books - even a dimensionless QuantityType can have a unit e.g. percent "%" or parts per million "ppm".

[mak-42]

It is defined as dimensionless number.

did I define something wrong?

[cweitkamp]

No, I would not say you did something wrong. You did something which is possible but not considered in all details. Despite this I would recommend you to use item type Number instead of item type Number:Dimensionless if you really expect a state without a unit.

[mak-42]

@cweitkamp, thanks a lot. I changed the item type to Number and the conditions started work as expected.