aggregate.js

// USAGE
// App.SomeModel = DS.Model.extend ({
//   users: DS.hasMany('users'),
//   contacts: DS.hasMany('contacts')
//   // Aggregate users and contacts into one array
//   people: App.computed.aggregate('users', 'contacts')
// })
//

App.computed.aggregate = function() {
  var args, options, properties;
  
  properties = Array.prototype.slice.call(arguments);
  
  args = properties.map((function(_this) {
    return function(prop) {
      return "" + prop;
    };
  })(this));
  
  options = {
    initialValue: [],
    addedItem: function(array, item, changeMeta, instanceMeta) {
      var observer;
      if (array.contains(item)) {
        return array;
      }
      observer = (function(_this) {
        return function() {
          if (!item.get('isLoaded')) {
            return;
          }
          item.removeObserver('isLoaded', observer);
          return array.addObject(item);
        };
      })(this);
      
      if (item.get('isLoaded')) {
        observer();
      } else {
        item.addObserver('isLoaded', observer);
      }
      
      return array;
    },
    removedItem: function(array, item, changeMeta, instanceMeta) {
      if (!array.length) {
        return;
      }
      if (!array.contains(item)) {
        return;
      }
      array.removeObject(item);
      return array;
    }
  };
  
  args.push(options);

  return Ember.arrayComputed.apply(this, args);
};