How do I associate one Backbone Model with another

问题:

I have the following JSON reply

{
   "results":[
      {
         "Product":{
            "id":"1",
            "short_name":"Infra - 2200 CAS Sma SIMO onl [DAS.1.1]",
            "serial_number":"DAS.1.1",
            "created_by":"Wesley Jace Tan",
            "modified_by":"Wesley Jace Tan",
            "created":"2013-02-11 07:58:20",
            "modified":"2013-02-11 07:58:20",
            "full_name_type":"2200",
            "full_name_cas_stk":"CAS",
            "full_name_size":"Small",
            "full_name_simo_mimo":"SIMO only",
            "full_name_product_code":"(2961-737)",
            "uom":"lot",
            "material":"Infra"
         },
         "Price":[
            {
               "id":"1",
               "product_id":"1",
               "source_file":"LTE Test File.xls",
               "for_financial_year":"FY12_13",
               "created_by":"Wesley Jace Tan",
               "modified_by":"Wesley Jace Tan",
               "created":"2013-02-11 07:58:20",
               "modified":"2013-02-11 07:58:20",
               "gross_unit":"50.00",
               "gross_total_value":"0.00",
               "gross_total_formula":"=K12*J12",
               "incentive_value":"5",
               "incentive_formula":"5",
               "net_price_unit":"0.00",
               "net_price_total_value":"0.00",
               "net_price_total_formula":"=N12*J12"
            }
         ]
      },
      {
         "Product":{
            "id":"2",
            "short_name":"Infra - 2200 CAS Sma SIMO to  [DAS.1.2]",
            "serial_number":"DAS.1.2",
            "created_by":"Wesley Jace Tan",
            "modified_by":"Wesley Jace Tan",
            "created":"2013-02-11 07:58:20",
            "modified":"2013-02-11 07:58:20",
            "full_name_type":"2200",
            "full_name_cas_stk":"CAS",
            "full_name_size":"Small",
            "full_name_simo_mimo":"SIMO to MIMO Retrofit",
            "full_name_product_code":"(2961-737)",
            "uom":"lot",
            "material":"Infra"
         },
         "Price":[
            {
               "id":"2",
               "product_id":"2",
               "source_file":"LTE Test File.xls",
               "for_financial_year":"FY12_13",
               "created_by":"Wesley Jace Tan",
               "modified_by":"Wesley Jace Tan",
               "created":"2013-02-11 07:58:20",
               "modified":"2013-02-11 07:58:20",
               "gross_unit":"11.00",
               "gross_total_value":"0.00",
               "gross_total_formula":"=K13*J13",
               "incentive_value":"24",
               "incentive_formula":"24",
               "net_price_unit":"0.00",
               "net_price_total_value":"0.00",
               "net_price_total_formula":"=N13*J13"
            }
         ]
      },
      {
         "Product":{
            "id":"3",
            "short_name":"Infra - 2200 CAS Sma Full MIM [DAS.1.3]",
            "serial_number":"DAS.1.3",
            "created_by":"Wesley Jace Tan",
            "modified_by":"Wesley Jace Tan",
            "created":"2013-02-11 07:58:20",
            "modified":"2013-02-11 07:58:20",
            "full_name_type":"2200",
            "full_name_cas_stk":"CAS",
            "full_name_size":"Small",
            "full_name_simo_mimo":"Full MIMO",
            "full_name_product_code":"(2961-737)",
            "uom":"lot",
            "material":"Infra"
         },
         "Price":[
            {
               "id":"3",
               "product_id":"3",
               "source_file":"LTE Test File.xls",
               "for_financial_year":"FY12_13",
               "created_by":"Wesley Jace Tan",
               "modified_by":"Wesley Jace Tan",
               "created":"2013-02-11 07:58:20",
               "modified":"2013-02-11 07:58:20",
               "gross_unit":"12.00",
               "gross_total_value":"0.00",
               "gross_total_formula":"=K14*J14",
               "incentive_value":"5",
               "incentive_formula":"5",
               "net_price_unit":"0.00",
               "net_price_total_value":"0.00",
               "net_price_total_formula":"=N14*J14"
            }
         ]
      }
   ]
}

The url to retrieve the above data is /products/index.json

The url to retrieve page 2 of products data is /products/index.json/page:2

My objective is to have a Backbone Product Model that has a Backbone Price Model.

Thus each entry in the above results array, will generate a Product and Price backbone model instance.

Is it ideal to have associations between Backbone models?

How do I achieve that?

UPDATE

I get the following error message after I tried the recommended solution. Uncaught TypeError: Object function (){return c.apply(this,arguments)} has no method 'fetch'

回答1:

You need override collection.parse. Sample code:

var Products = Backbone.Collection.extend({
            model: Product, 
            url: '/products/index.json',
            parse: function(response) {
                return _.map(response.results, // map each result to a product
                      function(result){
                          var product = result.Product;
                          product.price = new Price(result.Price); // create a price model
                          return product; // Backbone will convert the product to model
                      });
            }
        });