Overview
Some configuration options and item properties admit templates. Custom Sidebar
admits two templating systems, JavaScript templates or Jinja templates. JavaScript
templates are processed faster because the rendering is done in client side, Jinja
templates need to perform a WebSocket call to receive the template result, but in general you should not notice many differences between the two in terms of performance. The main differences between the two templating systems (apart from the syntax) are that JavaScript
can access client side data like DOM APIs, can return Promises, can work with Reactive JavaScript Variables and can execute several JavaScript
methods like opening dialogs or call services. Jinja
templates do not have all these features.