from-event element modifier

[alexlafroscia]

This implements an "element modifier" that can be given an event to listen to an observer that should subscribe to those events

class Foo extends Component {
  clicks = 0;

  handleClick() {
    this.clicks++;
  }
}

<button {{from-event 'click' this.handleClick}}>
  My Button
</button>

You can also pass an optional operator to transform the original observer before subscribing

import { filter } from 'rxjs/operators';

class Bar extends Foo {
  everyOtherClick() {
    return filter((event, index) => index % 2 === 0)
  }
}

<button {{from-event 'click' this.everyOtherClick this.handleClick}}>
  My Button
</button>

And, because of the way that Rx.Subject works, you can also get an observable from the handler if you want to do something specific with it

import { Subject } from 'rxjs';

class Bar extends Foo {
  subject = new Subject();

  init() {
    super.init(...arguments);

    this.subject.subscribe(event => {
      console.log(event);
    });
  }
}

<button {{from-event 'click' this.subject}}>
  My Button
</button>

[alexlafroscia]

PR blocked by something strange going on with ember-modifier-manager-polyfill in CI

ember-polyfills/ember-modifier-manager-polyfill#4