Is it possible to render a custom element in the Properties Panel other than the textfield and combo provided? A customized HTML?
I have been trying but the rendering never happens, many different bugs.
with several different aproaches, domifying and whatnot the element, but always getting “undefined”.
What is the correct way of creating a Properties Panel entry that allows deep customization?
It seems that you are using the new version of the Properties panel. Did you already have a look at our example on extensions work in the property panel?
To get started with extending the properties panel check out this example: bpmn-js-properties-panel Extension Example.
In case you’re giving it a try, we’d love to hear your feedback! 
I already cloned that repository and it works.
The problem arises when I try to instead of returning a
<TextFieldEntry />
, I want to return a custom element.
Whenever I do that, I have several issues.
I am trying to render a:
import Calendar from 'react-calendar';
But I always get errors with context, react, preact, hooks, no errors and no rendering… “useState” not being located ever and throwing errors… So many problems.
I can’t find a single example of an external react component being rendered inside Properties Panel.