Edit in JSFiddle

App = Ember.Application.create();


App.ApplicationController = Ember.Controller.extend({
  actions:{
    toggleLike:function(){
      this.set('liked',!this.get('liked'));
    }
  }
});

<script type="text/x-handlebars">
    <p>You {{#unless liked}}don't {{/unless}}like this.</p>
  <button {{action toggleLike}}>Click to toggle.</button>
</script>

              
            
          
            
              

External resources loaded into this fiddle: