Structuring models with ember data

Question

I've started using ember data and I'm having some issues getting started. If my json structure for ingredients is:

[
   {
      "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... }
]

I think this is how I would define my models:

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')
})

What should the server payload look like, and would I need to customize the REST adapter? Do I need to define the ingredient id: attr() in the model?

Any help in clarifying some of these concepts is appreciated.

Kingpin2k Kingpin2k · Accepted Answer · 2014-05-28T18:24:41

Generally model definitions are singular (additionally I changed nutrientinfo to 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')
})

The format would need to be as follows (from the endpoint, or using a serializer)

{
  // 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
    }
  ]
}

Here's an example using a serializer and your json, I've had to manually assign ids (despite this being invalid, you should send down ids, or use UUIDs), but this should give you an idea of how to use the serializer:

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

Structuring models with ember data

1 Answers