gistfile1.txt

M.Select = Em.Select.extend({
    value: Ember.computed(function(key, value){
       var content = this.get('content'),
             selection = this.get('selection'),
             self = this, 
             optionValuePath = this.get('optionValuePath');
       
       if ( selection ) {
         this.setPath('bindingContext.type', selection.type)
       }
       if (value != undefined){
            content.forEach(function(item, idx){
               if (item.id && item.id == value)
               {
                    self.set('selection', item);
                    return;
               }
            });

            return value;
       }

        return this.get('selection')?
            this.get('selection').id : 
            null;
    }).property('selection').cacheable()
});