dom-trigger

components.dom-trigger.js

import Ember from 'ember';

export default Ember.Component.extend({
  tagName: '',
  
  didInsertElement() {
    let onInsert = this.get('onInsert');
    if (onInsert) {
      onInsert();
    }
  },
  
  willDestroyElement() {
    let onRemove = this.get('onRemove');
    if (onRemove) {
      onRemove();
    }
  }
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle'
});

helpers.not.js

import Ember from 'ember';

export function not([val]/*, hash*/) {
  return !val;
}

export default Ember.Helper.helper(not);

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{outlet}}
<br>
<br>
<button onclick={{action (mut test) (not test)}}>Toggle: {{if test 'visible' 'hidden'}}</button>

{{#if test}}
  {{dom-trigger
  	onInsert=(action (mut blah) 'in')
    onRemove=(action (mut blah) 'out')
    }}
{{/if}}

{{blah}}

templates.components.dom-trigger.hbs

{{yield}}

twiddle.json

{
  "version": "0.12.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.12.0",
    "ember-template-compiler": "2.12.0",
    "ember-testing": "2.12.0"
  },
  "addons": {
    "ember-data": "2.12.1"
  }
}