OH3 rendering Number:Temperature state in Web UI Marker Expression

Setup, Configuration and Use Beginners
2

There really is no “correct” types. However, I think “Measurement (Humidity)” and “Measurement (Temperature)” would be more meaningful since that is what those Items represent. Conversely, if you had a setpoint for a heater, I’d use “Setpoint (Temperature)”. There really isn’t a great pair of tags for battery levels. I tend to use “lowBattery (Power)” for mine. But this isn’t about correct and incorrect. It’s about providing meaning in the model.

The state is as it is because this is a Number:Temperature Item. Number:X type Items come with a unit and will convert between units for you automatically. But it also includes the units when you output the state.

But you have control over this to some degree. You can set how the state get’s formatted using the “State Description” Item metadata. That will let you configure the “displayState”. You can definitely use that to control the precision and which units are used. But I don’t know if there is a way to exclude the units entirely that way.

According to Building Pages in the OH3 UI: documentation draft (2/3), you have access to JS Math and JSON and any method that is already on the object (e.g. split). But not any of the parsing functions.

So I think your options are:

  • use a Number if you can so it doesn’t use Units of Measurement (UoM) and therefore include the unit, but even then, is the state provided as a string or do you really get the number value?
  • consider whether this matters, I think you can do > and < type comparisons between strings and it will give you the result alphabetically. If your temp is pretty much always two digits this could potentially work just fine.
  • if you need the UoM elsewhere you could create a proxy Number Item to hold the value without the UoM to use in the expression

Those are really just work arounds though. I also think you should file an issue .The question is where though as I can see two approaches to solve this.

  1. Modify openhab-core to provide a way to define a label format in such a way that the unit can be excluded. With that you can use the displayState to format the state without the units.

  2. Modify the UI code (if it’s even possible) to let us access some more parts of JS so we can extract the units and parse the number in the expression.