Backbone-relational parsing nested models - backbone.js

Question

I thought backbone-relational automatically parses and makes nested models ready of nested json. I have a big json like this
{ //ItemResultModel
"items":[
{ //ItemModel
"id":120514,
"recordDate":"2013-10-19T00:00:00",
"owner":{
"id":"d14a052b-a9df-45ba-92e5-58adfe28c10c",
"firstName":null,
"lastName":null
},
"features":[
{ //FeatureModel
"id":1,
"properties":[
{ //PropertyModel
"id":814518,
"values":[
"5"
]
}
//,other properties
]
}
//, other features
]
}
],
//other models and collections
"facets":{
},
"totalCount":7
}
And i tried to parse this json to my models by using backbone relational. And here are my models:
app.Models.ItemResultModel = Backbone.RelationalModel.extend({
relations: [{
type: Backbone.HasMany,
key: 'items',
relatedModel: 'app.Models.ItemModel',
collectionType: 'app.Collections.ItemCollection',
parse: true
}]
});
app.Collections.ItemCollection = Backbone.Collection.extend({
model: app.Models.ItemModel
});
app.Models.ItemModel = Backbone.RelationalModel.extend({
urlRoot: '/api/Item',
relations: [{
type: Backbone.HasMany,
key: 'features',
relatedModel: 'app.Models.FeatureModel',
collectionType: 'app.Collections.FeatureCollection',
parse: true
}]
});
app.Models.FeatureModel = Backbone.RelationalModel.extend({
relations: [{
type: Backbone.HasMany,
key: 'properties',
relatedModel: 'app.Models.ItemPropertyModel',
collectionType: 'app.Collections.ItemPropertyCollection'
}]
});
app.Collections.FeatureCollection = Backbone.Collection.extend({
model:app.Models.FeatureModel
});
and the same schema goes on for properties and deeper levels. The problem is, when i fetch the ItemResultModel from server i don't get my models populated after second level, i mean, i don't get features models.
this.model.get('items'); // this has some item models as i expect
this.model.get('items').at(0).get('features');//items does not have any feature model
How can i make my models ready after fetching the wrapper model? If you offer some solution without using backbone-relational, by using parse method, it is ok too.

Answer 1

if you use simple backbone model?
this.model.get('items')[0].features
or if you create collection based on items array:
this.collection.at(0).get('features')

Answer 2

Now I realized there are similar question. Sorry for this.
No need to use backbone-relational for this.
app.Models.ItemResultModel = Backbone.Model.extend({
subCollections: {
items: app.Collections.ItemCollection
},
parse: function (response) {
//Solution
this.set({
itemsCollection: new app.Collections.ItemCollection(response.items, { parse: true })
});
delete response.items;
//Better solution
for (var key in this.subCollections) {
var embeddedClass = this.subCollections[key];
var embeddedData = response[key];
response[key] = new embeddedClass(embeddedData, { parse: true });
}
return response;
}
})
And you can do the same thing for all levels of hierarchy.