使用 ember 数据构建模型

Question

我已开始使用 ember 数据，但在开始使用时遇到了一些问题。如果我的 json 成分结构是：

[
   {
      "name":"flax seed",
      "retailer":"www.retailer.com",
      "nutrient_info":[
         {
            "type":"vitamin A",
            "amount":"50mg"
         },
         {
            "type":"calcium",
            "amount":"30mg"
         }
      ]
   },
   {
      "name":"soy milk",
      "retailer":"www.retailer-two.com",
      "nutrient_info":[
         {
            "type":"vitamin D",
            "amount":"500mg"
         },
         {
            "type":"niacin",
            "amount":"5000mg"
         }
      ]
   },
   { other ingredients... }
]

我认为这就是我定义模型的方式：

var attr = DS.attr,
    hasMany = DS.hasMany,
    belongsTo = DS.belongsTo

App.Ingredients = DS.Model.extend({
    // id: attr('number'),  // don't include id in model?
    name: attr('string'),
    retailer: attr('string'),
    nutrientinfo: hasMany('nutrients')
})

App.Nutrients = DS.Model.extend({
    type: attr('string'),
    amount: attr('string'),

    ingredient: belongsTo('ingredients')
})

服务器负载应该是什么样的，我是否需要自定义 REST 适配器？我是否需要在模型中定义成分id: attr()？

感谢任何帮助澄清其中一些概念。

Answer 1

通常模型定义是单数的（另外我将 nutritioninfo 更改为 nutrient_info）：

App.Ingredient = DS.Model.extend({
    // id: attr('number'),  // don't include id in model?
    name: attr('string'),
    retailer: attr('string'),
    nutrient_info: hasMany('nutrient')
})

App.Nutrient = DS.Model.extend({
    type: attr('string'),
    amount: attr('string'),
    ingredient: belongsTo('ingredient')
})

格式需要如下（来自端点，或使用序列化程序）

{
  // Ingredient records
  ingredients:[
    {
      id:1,
      "name":"flax seed",
      "retailer":"www.retailer.com",
      "nutrient_info":[1,2]
    },
    {
      id:2,
      "name":"soy milk",
      "retailer":"www.retailer-two.com",
      "nutrient_info":[3,4]
    },
    { other ingredients... }
  ],

  // Nutrient records
  nutrients: [
    {
      id:1,
      "type":"vitamin A",
      "amount":"50mg",
      ingredient:1
    },
    {
       id:2,
       "type":"calcium",
       "amount":"30mg",
      ingredient:1
    },
    {
       id:3,
       "type":"vitamin D",
       "amount":"500mg",
      ingredient:2
    },
    {
       id:4,
       "type":"niacin",
       "amount":"5000mg",
      ingredient:2
    }
  ]
}

这是一个使用序列化程序和您的 json 的示例，我必须手动分配 id（尽管这无效，您应该发送 id 或使用 UUID），但这应该让您了解如何使用序列化器：

App.IngredientSerializer = DS.RESTSerializer.extend({
  extractArray: function(store, type, payload, id, requestType)   {
    var ingredients = payload,
        nutrientId = 0,
        ingredientId = 0,
        ids = [],
        nutrients = [];

    ingredients.forEach(function(ing) {
      ing.id = ingredientId++;
      var nInfo = ing.nutrient_info,
          nIds = [];

      nInfo.forEach(function(n){
        n.id = nutrientId++;
        n.ingredient = ing.id;
        nIds.push(n.id);
        nutrients.push(n);
      });
      ing.nutrient_info = nIds;
    });

    payload = {ingredients:ingredients, nutrients:nutrients};

    return this._super(store, type, payload, id, requestType);
  }
});

http://emberjs.jsbin.com/OxIDiVU/537/edit