Units of Measure - oh-chart

[weymann (Bernd Weymann)]

@rlkoshak

All I can say is it was deliberately written such that bindings cannot supply the unit metadata, only the state description. I personally didn’t like that choice and said so on the thread but the maintainers disagreed.

I’m on the same page!

@rlkoshak

I don’t understand how this is relevant. Do you list this because it takes an extra step to set the unit when creating Items that way? It shouldn’t be challenging to add unit to the Model. If you do create an issue for that, throw in adding unit to the “create equipment from thing” form too.

Sure, this will solve the setup. But I think the problem is deeper (see also last quote).

Assume you’re a normal user without deeper knowledge, please try .
You install a car binding and setup everythig. What’s your assumption of Unit State of Charge? It’s Percent right? But it’s shown as 0.83 one. Question already asked. I as a user would think "Dumb Developer! Cannot present the right unit and now I have to do it on my own. "

Now change your role and assume you’re developer of this binding.
Will you describe in readme "Dear user, if you add items to the channels please take care of units for mileage, range, trip computer fuel level, state of charge, …? There’s already enough to implement to discover i18n and present miles or kilometers. And after that mileage is presentf in inches?

There must be a way to define it as binding developer.

And of course the user can overrule afterwards. State of charge shall be per mill - feel free to change as you describe above! But don’t bother the 99,9% of users which are expecting kilometers, miles and percentage!

@rlkoshak

Changing the unit on the Item doesn’t retroactively change the values stored in the database. And the database doesn’t store the unit at all. So if a value in W made it into the database and you later change the unit to kW, there’s nothing to tell OH that that the old value(s) are in W so it treats it as kW.

Description above shows how to setup. But I have items for approx 4 years with nice data inside, e.g. my driven kilometers. Now it’s converted into meters for all these years and I cannot change it anymore, right?
That’s my origin question - how can I dsipay a chart with my driven kilometers, not meters.