在backbone.js中的两个视图上访问集合

Question

嗨我有一个集合和两个视图.在我的view1上我将数据添加到我的集合中,view2将只显示和显示有关集合的任何更改.但我无法让它发挥作用.问题是我原来是这样做的

return new CartCollection(); 

但他们说这是一个不好的做法所以我删除改变它.但是当我在view1上实例化购物车集合时,它会添加,但似乎view2没有看到更改并且什么都不呈现.

有任何想法吗？

这是我的购物车系列.

define([
 'underscore',
 'backbone',
 'model/cart'
], function(_, Backbone, CartModel) {
var CartCollection = Backbone.Collection.extend({
model : CartModel,
initialize: function(){
}
});
return CartCollection;
});

这是我的itemView(view1)

AddToCart:function(ev){
    ev.preventDefault();
    //get data-id of the current clicked item
    var id = $(ev.currentTarget).data("id");
    var item = this.collection.getByCid(id);
    var isDupe = false;
    //Check if CartCollection is empty then add
    if( CartCollection.length === 0){
        CartCollection.add([{ItemCode:item.get("ItemCode"),ItemDescription:item.get("ItemDescription"),SalesPriceRate:item.get("RetailPrice"),ExtPriceRate:item.get("RetailPrice"),WarehouseCode: "Main",ItemType : "Stock",LineNum:1 }]);
    }else{
        //if check if the item to be added is already added, if yes then update QuantityOrdered and ExtPriceRate
        _.each(CartCollection.models,function(cart){
            if(item.get("ItemCode") === cart.get("ItemCode")){
                isDupe = true;
                var updateQty = parseInt(cart.get("QuantityOrdered"))+1;
                var extPrice = parseFloat(cart.get("SalesPriceRate") * updateQty).toFixed(2);
                cart.set({ QuantityOrdered: updateQty });
                cart.set({ ExtPriceRate: extPrice });
            }
        });
        //if item to be added has no duplicates add new item
        if( isDupe == false){ 
            var cartCollection = CartCollection.at(CartCollection.length - 1);
            var lineNum = parseInt( cartCollection.get("LineNum") ) + 1;
            CartCollection.add([{ItemCode:item.get("ItemCode"),ItemDescription:item.get("ItemDescription"),SalesPriceRate:item.get("RetailPrice"),ExtPriceRate:item.get("RetailPrice"),WarehouseCode: "Main",ItemType : "Stock",LineNum:lineNum}]); 
            }
    }
    CartListView.render();
}

我的购物车视图(view2)

render: function(){
  this.$("#cartContainer").html(CartListTemplate);
  var CartWrapper = kendobackboneModel(CartModel, {
     ItemCode: { type: "string" },
     ItemDescription: { type: "string" },
     RetailPrice: { type: "string" },
     Qty: { type: "string" },
  });
  var CartCollectionWrapper = kendobackboneCollection(CartWrapper);
  this.$("#grid").kendoGrid({
    editable: true,
    toolbar: [{ name: "save", text: "Complete" }],
    columns: [
        {field: "ItemDescription", title: "ItemDescription"},
        {field: "QuantityOrdered", title: "Qty",width:80},
        {field: "SalesPriceRate", title: "UnitPrice"},
        {field: "ExtPriceRate", title: "ExtPrice"}
    ],
    dataSource: {
      schema: {model: CartWrapper},
      data: new CartCollectionWrapper(CartCollection),
     }
  });

},

Answer 1

问题是你已经创建了2个不同的CartCollection实例.因此,当您将数据更新或获取到一个实例中时,另一个实例不会更改,但保持不变.

相反,您需要在2个视图中使用相同的CartCollection实例(或者保持2个不同步).假设两个视图都在同一个require.js模块中,您需要:

1)实例化CartCollection实例并将其存储在两个视图都可以访问的位置.您可以将它放在路由器,父视图或其他任何地方.例如

var router = Backbone.Router.extend({});
router.carts = new CartCollection();

2)您需要将CartCollection实例传递给每个视图.例如

var view1 = new ItemView({ collection: router.carts });
var view2 = new CartView({ collection: router.carts });

您可能还想将Cart模型传递给CartView而不是整个集合.例如

var cartModel = router.carts.get(1);
var view2 = new CartView({ model: cartModel });