multiselect-toggle

controllers.application.js

import Ember from 'ember'

export default Ember.Controller.extend({
  appName: 'Twiddle',
  
  selected: [],
  
  actions: {
    toggle(index) {
      const indexOf = this.selected.indexOf(index)

      if (indexOf >= 0) {
        this.selected.splice(indexOf, 1)
      } else {
        if (this.selected.length >= 5) {
          return alert('You cannot select more than 5 fruits')
        }

        this.selected.push(index)
      }
      
      this.notifyPropertyChange('selected')
    }
  }
})

helpers.is-selected.js

import Ember from 'ember'

export function isSelected([selected, index]) {
  return selected.indexOf(index) >= 0 && 'selected'
}

export default Ember.Helper.helper(isSelected)

routes.application.js

import Ember from 'ember'

export default Ember.Route.extend({
  model() {
    return ["apple","orange","mango","papaya","pineapple", "gova","orange"]
  }
})

styles.app.css

* {
  margin: 0;
  padding: 0;
}

body {
  margin: 1em;
  font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
  font-size: 12pt;
}

ul {
  margin: 1em 2em;
}

li {
  margin: 1em 0;
}

li.selected:after {
	content: '\2714';
  margin-left: 0.5em;
}

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<ul>
	{{#each model as |fruit index|}}
  	<li class="{{is-selected selected index}}" {{action 'toggle' index}}>{{fruit}}</li>
  {{/each}}
</ul>

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"
  }
}