Implementation of delegated events

[titoBouzout]

Delegated events are a nice concept that improves performance of event handlers[citation needed], but that unintentionally introduce some edge cases. There are reasons to believe that we could keep delegated events as intended by dom-expressions, without messing unrelated expectations.

Opening this issue to investigate what could be done about it, and if the intention would be achievable.

[titoBouzout]

An idea that came to mind the other day,

For Portals, it may be possible to add a real event listener, prevent default, and redispatch the event in the $host. That way the event will bubble the component tree, but things like preventDefault will still work. In pseudocode on the lines of :

<Portal on:click={(e)=>{
  e.preventDefault()
  $portalHost.dispatchEvent(new Event('click'))
}}/>

What this is trying, is to make match the behaviour of delegated events with native events. I think having delegated events behaving differently to native events it's a regretful mistake, but at the same time bubbling to a different parent is not something supported by the platform, so maybe this idea I came with could? alleviate the problem