Auto Trigger

components.auto-trigger.js

import Ember from 'ember';

export default Ember.Component.extend({
  model: [
    {label:'a'},
    {label:'b'}
    ],
  
  selected: null,
  
 	triggerOpen(powerSelect) {
    const event = new window.Event('mousedown', { bubbles: true, cancelable: true, view: window });
    powerSelect.dispatchEvent(event);
  },

  didRender() {
    const elm = this.$('.ember-power-select-trigger')[0];
    this.triggerOpen(elm);
  },
  
  actions: {
   onchange() {}
  }
});

controllers.application.js

import Ember from 'ember';

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

templates.application.hbs

{{auto-trigger}}

templates.components.auto-trigger.hbs

{{#power-select
    options=model
    selected=selected
    searchEnabled=true
    onchange=(action "onchange")
    searchField='label'
    as |item|}}
  {{item.label}}
{{/power-select}}

twiddle.json

{
  "version": "0.10.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.6.0",
    "ember-data": "2.6.1",
    "ember-template-compiler": "2.6.0"
  },
  "addons": {
  	"ember-power-select": "0.10.10"
  }
}