localized-placeholder

application.controller.js

import Ember from 'ember';

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

application.template.hbs

<p>Expect to see 'Bonjour' but placeholder text is '_hello'</p>
{{localized-input placeholder="_hello_"}}

localized-input.component.js

import Ember from 'ember';

Ember.STRINGS = {
	'_hello_': 'Bonjour'
}

export default Ember.Component.extend({
  tagName:'input',
  attributeBindings: ['placeholder'],
  willInsertElement: function() {
  	this._super();
    var placeholder = this.get('placeholder');
    if (placeholder) {
    	this.set('placeholder', placeholder.loc());
    }
  }
});

twiddle.json

{
  "version": "0.4.13",
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.1.0/ember.debug.js",
    "ember-data": "https://cdnjs.cloudflare.com/ajax/libs/ember-data.js/2.1.0/ember-data.js",
    "ember-template-compiler": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.1.0/ember-template-compiler.js"
  }
}