Add a streamElement property to the turbo:before-stream-render event

[nbgoodall]

This adds a streamElement property to the detail of the turbo:before-stream-render. Feel free to do with it as you wish!

Personally I'm using this for intercepting the event to smoothly transition between the frames, e.g.:

document.addEventListener('turbo:before-stream-render', function(event) {
  event.preventDefault()

  /* Transition the old frame away ... */

  event.detail.streamElement.performAction()
})

Thank you for all your work! 🙏

[panda-madness]

Wouldn't it be better to just pass in a reference to the entire StreamElement? That way we get access to every aspect of the stream action, not just the template. Could also straight up call performAction directly instead of manually recreating that bit.

[sstephenson]

Thanks for the patch! You can already access the stream element using the event.target property, so I don't think we need to pass anything along in the details object 👍

[pySilver]

Current example is:

document.addEventListener("turbo:before-stream-render", function (event) {
  event.preventDefault();

  /* Transition the old frame away ... */
  console.log("turbo:before-stream-render", event.detail.newStream.target);

  event.detail.newStream.performAction();
});