list-limiter

components.my-component.js

import Ember from 'ember';

export default Ember.Component.extend({
  tagName: 'ul',
  didReceiveAttrs() {
    if (this.get('limit')) {
      this.set('list.length', this.get('limit')); 
    }
  }
});

controllers.application.js

import Ember from 'ember';

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

routes.application.js

import Ember from 'ember';

export default Ember.Route.extend({
	setupController(controller) {
     let list = [
       { name: 'bar'},
       { name: 'baz'},
       { name: 'bap'},
       { name: 'bab'},
       { name: 'bam'}
     ];
   	 controller.set('foo', 'bar');
     controller.set('list', list);
  }
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{outlet}}
{{foo}}
<br>
<br>
{{my-component limit=3 list=list}}

templates.components.my-component.hbs

{{#each list as |listItem index|}}
    <li>{{listItem.name}}</li>
{{/each}}

twiddle.json

{
  "version": "0.7.2",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.4.4/ember.debug.js",
    "ember-data": "https://cdnjs.cloudflare.com/ajax/libs/ember-data.js/2.4.3/ember-data.js",
    "ember-template-compiler": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.4.4/ember-template-compiler.js"
  }
}