I wanted to create a custom card view for my state / component, however I’m unable to do that.
I have used a Basic MQTT Example to get an understanding on how to create a Python component. Having that I wanted to customize my state card, that is displayed by default like that:
Since I’m using frontend in dev mode, any change is followed with calling script/build_frontend, followed by home-assistant-polymer's npm run dev command.
I know that the component is loaded correctly, as I can see the HTML being successfully loaded in network panel of devtools. No exceptions in the console, the custom element is loaded correctly.
I also know that there were some breaking changes recently, related to custom_ui_state_card in configuration, which I also adapted.
For your convenience I have put the simplified code in a dedicated repo.
Any ideas what am I doing wrong?