Invalidating cached property

gistfile1.coffee

GS.cMenu = Em.Object.create
	searchTerm : ""
	menu: null
	restaurantLocation: null
	cart: Ember.A([])
	addToCart: (orderItem,control) ->
		newOrderItem =	{orderItem: orderItem, id: guidGenerator()}
		newA = @cart
		newA.pushObject newOrderItem
		@set 'GS.cMenu.cart',newA
		newOrderItem

GS.vMenuItem = Em.View.extend
	templateName: 'tMenuItem'
	cartBinding: "GS.cMenu.cart"
	cartItems: (->
		return @cart.filter ((obj) -> 
			return @content.MenuItemID is obj.orderItem.MenuItemID)		, this
	).property('cart').cacheable()
	priceMoney: (->
		@content.Price.formatMoney 2, '.', ','
	).property()	
	addItem: ->
		newItem = GS.cMenu.addToCart @content, this