Symfony-ux inspired events for autocomplete

[Deksor]

Hello !
I am making this PR because I need to be able to customize autocomplete fields in my project to improve performance and fine tune some specific features of my website.

In symfony-ux autocomplete, it is very easy thanks to a couple of events dispatched right before and right after the autocomplete fields have been created : https://symfony.com/bundles/ux-autocomplete/current/index.html#extending-tom-select.

So I took inspiration from this part of symfony-ux autocomplete's code:
https://github.com/symfony/ux-autocomplete/blob/2.x/assets/src/controller.ts

I am aware that someone has suggested to use symfony-ux in easyadmin :
#6967

But for the time being (whether ea moves to symfony-ux or not) is it possible to dispatch these events every time an Autocomplete object is created by EasyAdmin's frontend ?

This would simplify greatly the process of customizing autocomplete fields in easyadmin !

Instead of manually grabbing the select element by its id and finding tomselect in that select, it would become as simple as

document.addEventListener('ea.autocomplete.connect', (event) => {
    // custom code goes here
});

[Seb33300]

Wouldn't it be better to replace EasyAdmin's implementation of Tom Select with Symfony UX Autocomplete?

[Deksor]

Oh absolutely having Symfony UX autocomplete in easy admin would be awesome !
I was just suggesting this because it would be faster to implement this 10 lines fix than switching ea to Symfony UX autocomplete.
But if it is planned to move easyadmin to Symfony UX autocomplete (and turbo, please 👍 ) it would be better.

[javiereguiluz]

Using UX autocomplete is a long-term goal (for EasyAdmin 5.x version) so, let's merge this now to provide at least something for those needing this.

Thanks @Deksor!