Feature request: did-enter-viewport and did-exit-viewport element modifiers

[gmurphey]

Would be awesome to be able to do things like:

<div
  {{did-enter-viewport enterCallback}}
  {{did-exit-viewport exitCallback}}
>
  Foo
</div>

Where enterCallback and exitCallback are functions or actions that receive the element as a parameter.

[snewcomer]

Interesting idea and thx for putting up an issue. So you are referring to this RFC I'm guessing? https://github.com/emberjs/rfcs/pull/353/files

Since these functions are called once I believe, what exactly would these modifiers do? What happens when they elements they are bound to are not in viewport, but are still only called once (ie. not watchign the DOM)

[snewcomer]

@gmurphey Is this something you would want to work on? Otherwise, I'll see about getting it done on our side!

[snewcomer]

I'm starting work on this. There is quite a bit to do, including ensuring we have a shared cache that can be referenced across boundaries (mixin / modifier)

[snewcomer]

@gmurphy #179. Seems pretty simple and would require installing https://github.com/emberjs/ember-render-modifiers and using the ‘did-insert’ hook. What do you think?