ember-i18n - Internalization Support

I am currently using jamesarosen/ember-i18n for internalization support on my ember 1.5.1 app.

I have two languages. English and French.

Em.I18n.translations = {
  en: {
    animal: {
      cat: 'cat',
      dog: 'dog'
    }
  },

  fr: {
    animal: {
      cat: 'chat',
      dog: 'chien'
    }
  }
};

In my handlebars template I have: -

{{t animal.cat}}

However I get the message:

Missing translation: animal.cat.

It would work if I place:

{{t en.animal.cat}} or {{t fr.animal.cat}}

What is the best practice to get this working and to make it automatically switchable between the two languages? I have tried setting this at the top of my file:

Em.I18n.locale = 'fr';

I found the answer to this:

Adding this helper:

Ember.Handlebars.registerHelper('i18n', function(property, options) {
  var params = options.hash,
      self = this;

  // Support variable interpolation for our string
  Object.keys(params).forEach(function (key) {
    params[key] = Em.Handlebars.get(self, params[key], options);
  });

  property = Em.I18n.locale + '.' + property;

  return Em.I18n.t(property, params);
});

And making sure this is set:

Em.I18n.locale = 'en';

Using the updated handlebars reference:

{{i18n animal.cat}}