DS.JSONSerializer Class packages/ember-data/lib/serializers/json_serializer.js:6

In Ember Data a Serializer is used to serialize and deserialize records when they are transferred in and out of an external source. This process involves normalizing property names, transforming attribute values and serializing relationships.

For maximum performance Ember Data recommends you use the RESTSerializer or one of its subclasses.

JSONSerializer is useful for simpler or legacy backends that may not support the http://jsonapi.org/ spec.

Show:

_canSerialize

(key) Boolean private

Check attrs.key.serialize property to inform if the key can be serialized

Parameters:

key String

Returns:

Boolean
true if the key can be serialized

_getMappedKey

(key) String private

Looks up the property key that was set by the custom attr mapping passed to the serializer.

Parameters:

key String

Returns:

String
key

applyTransforms

(type, data) Object private

Given a subclass of DS.Model and a JSON object this method will iterate through each attribute of the DS.Model and invoke the DS.Transform#deserialize method on the matching property of the JSON object. This method is typically called after the serializer's normalize method.

Parameters:

type subclass of DS.Model
data Object
The data to transform

Returns:

Object
data The transformed data object

extract

(store, type, payload, id, requestType) Object

The extract method is used to deserialize payload data from the server. By default the JSONSerializer does not push the records into the store. However records that subclass JSONSerializer such as the RESTSerializer may push records into the store as part of the extract call.

This method delegates to a more specific extract method based on the requestType.

Example

1
2
3
4
5
6
7
8
9
var get = Ember.get;
socket.on('message', function(message) {
  var modelName = message.model;
  var data = message.data;
  var type = store.modelFor(modelName);
  var serializer = store.serializerFor(type.typeKey);
  var record = serializer.extract(store, type, data, get(data, 'id'), 'single');
  store.push(modelName, record);
});

Parameters:

store DS.Store
type subclass of DS.Model
payload Object
id String or Number
requestType String

Returns:

Object
json The deserialized payload

extractArray

(store, type, payload, id, requestType) Array

extractArray is used to deserialize an array of records returned from the adapter.

Example

1
2
3
4
5
6
7
App.PostSerializer = DS.JSONSerializer.extend({
  extractArray: function(store, type, payload) {
    return payload.map(function(json) {
      return this.extractSingle(store, type, json);
    }, this);
  }
});

Parameters:

store DS.Store
type subclass of DS.Model
payload Object
id String or Number
requestType String

Returns:

Array
array An array of deserialized objects

extractCreateRecord

(store, type, payload, id, requestType) Object

extractCreateRecord is a hook into the extract method used when a call is made to DS.Store#createRecord. By default this method is alias for extractSave.

Parameters:

store DS.Store
type subclass of DS.Model
payload Object
id String or Number
requestType String

Returns:

Object
json The deserialized payload

extractDeleteRecord

(store, type, payload, id, requestType) Object

extractDeleteRecord is a hook into the extract method used when a call is made to DS.Store#deleteRecord. By default this method is alias for extractSave.

Parameters:

store DS.Store
type subclass of DS.Model
payload Object
id String or Number
requestType String

Returns:

Object
json The deserialized payload

extractFind

(store, type, payload, id, requestType) Object

extractFind is a hook into the extract method used when a call is made to DS.Store#find. By default this method is alias for extractSingle.

Parameters:

store DS.Store
type subclass of DS.Model
payload Object
id String or Number
requestType String

Returns:

Object
json The deserialized payload

extractFindAll

(store, type, payload, id, requestType) Array

extractFindAll is a hook into the extract method used when a call is made to DS.Store#findAll. By default this method is an alias for extractArray.

Parameters:

store DS.Store
type subclass of DS.Model
payload Object
id String or Number
requestType String

Returns:

Array
array An array of deserialized objects

extractFindBelongsTo

(store, type, payload, id, requestType) Object

extractFindBelongsTo is a hook into the extract method used when a call is made to DS.Store#findBelongsTo. By default this method is alias for extractSingle.

Parameters:

store DS.Store
type subclass of DS.Model
payload Object
id String or Number
requestType String

Returns:

Object
json The deserialized payload

extractFindHasMany

(store, type, payload, id, requestType) Array

extractFindHasMany is a hook into the extract method used when a call is made to DS.Store#findHasMany. By default this method is alias for extractArray.

Parameters:

store DS.Store
type subclass of DS.Model
payload Object
id String or Number
requestType String

Returns:

Array
array An array of deserialized objects

extractFindMany

(store, type, payload, id, requestType) Array

extractFindMany is a hook into the extract method used when a call is made to DS.Store#findMany. By default this method is alias for extractArray.

Parameters:

store DS.Store
type subclass of DS.Model
payload Object
id String or Number
requestType String

Returns:

Array
array An array of deserialized objects

extractFindQuery

(store, type, payload, id, requestType) Array

extractFindQuery is a hook into the extract method used when a call is made to DS.Store#findQuery. By default this method is an alias for extractArray.

Parameters:

store DS.Store
type subclass of DS.Model
payload Object
id String or Number
requestType String

Returns:

Array
array An array of deserialized objects

extractMeta

(store, type, payload)

extractMeta is used to deserialize any meta information in the adapter payload. By default Ember Data expects meta information to be located on the meta property of the payload object.

Example

1
2
3
4
5
6
7
8
App.PostSerializer = DS.JSONSerializer.extend({
  extractMeta: function(store, type, payload) {
    if (payload && payload._pagination) {
      store.metaForType(type, payload._pagination);
      delete payload._pagination;
    }
  }
});

Parameters:

store DS.Store
type subclass of DS.Model
payload Object

extractSave

(store, type, payload, id, requestType) Object

extractSave is a hook into the extract method used when a call is made to DS.Model#save. By default this method is alias for extractSingle.

Parameters:

store DS.Store
type subclass of DS.Model
payload Object
id String or Number
requestType String

Returns:

Object
json The deserialized payload

extractSingle

(store, type, payload, id, requestType) Object

extractSingle is used to deserialize a single record returned from the adapter.

Example

1
2
3
4
5
6
7
8
App.PostSerializer = DS.JSONSerializer.extend({
  extractSingle: function(store, type, payload) {
    payload.comments = payload._embedded.comment;
    delete payload._embedded;

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

Parameters:

store DS.Store
type subclass of DS.Model
payload Object
id String or Number
requestType String

Returns:

Object
json The deserialized payload

extractUpdateRecord

(store, type, payload, id, requestType) Object

extractUpdateRecord is a hook into the extract method used when a call is made to DS.Store#update. By default this method is alias for extractSave.

Parameters:

store DS.Store
type subclass of DS.Model
payload Object
id String or Number
requestType String

Returns:

Object
json The deserialized payload

keyForAttribute

(key) String

keyForAttribute can be used to define rules for how to convert an attribute name in your model to a key in your JSON.

Example

1
2
3
4
5
App.ApplicationSerializer = DS.RESTSerializer.extend({
  keyForAttribute: function(attr) {
    return Ember.String.underscore(attr).toUpperCase();
  }
});

Parameters:

key String

Returns:

String
normalized key

keyForRelationship

(key, relationship) String

keyForRelationship can be used to define a custom key when serializing relationship properties. By default JSONSerializer does not provide an implementation of this method.

Example

1
2
3
4
5
 App.PostSerializer = DS.JSONSerializer.extend({
   keyForRelationship: function(key, relationship) {
      return 'rel_' + Ember.String.underscore(key);
   }
 });

Parameters:

key String
relationship String
type

Returns:

String
normalized key

normalize

(type, hash) Object

Normalizes a part of the JSON payload returned by the server. You should override this method, munge the hash and call super if you have generic normalization to do.

It takes the type of the record that is being normalized (as a DS.Model class), the property where the hash was originally found, and the hash to normalize.

You can use this method, for example, to normalize underscored keys to camelized or other general-purpose normalizations.

Example

1
2
3
4
5
6
7
8
9
10
11
12
13
App.ApplicationSerializer = DS.JSONSerializer.extend({
  normalize: function(type, hash) {
    var fields = Ember.get(type, 'fields');
    fields.forEach(function(field) {
      var payloadField = Ember.String.underscore(field);
      if (field === payloadField) { return; }

      hash[field] = hash[payloadField];
      delete hash[payloadField];
    });
    return this._super.apply(this, arguments);
  }
});

Parameters:

type subclass of DS.Model
hash Object

Returns:

Object

normalizeAttributes

private

normalizeId

private

normalizePayload

(payload) Object

You can use this method to normalize all payloads, regardless of whether they represent single records or an array.

For example, you might want to remove some extraneous data from the payload:

1
2
3
4
5
6
7
App.ApplicationSerializer = DS.JSONSerializer.extend({
  normalizePayload: function(payload) {
    delete payload.version;
    delete payload.status;
    return payload;
  }
});

Parameters:

payload Object

Returns:

Object
the normalized payload

normalizeRelationships

private

normalizeUsingDeclaredMapping

private

serialize

(record, options) Object

Called when a record is saved in order to convert the record into JSON.

By default, it creates a JSON object with a key for each attribute and belongsTo relationship.

For example, consider this model:

1
2
3
4
5
6
App.Comment = DS.Model.extend({
  title: DS.attr(),
  body: DS.attr(),

  author: DS.belongsTo('user')
});

The default serialization would create a JSON object like:

1
2
3
4
5
{
  "title": "Rails is unagi",
  "body": "Rails? Omakase? O_O",
  "author": 12
}

By default, attributes are passed through as-is, unless you specified an attribute type (DS.attr('date')). If you specify a transform, the JavaScript value will be serialized when inserted into the JSON hash.

By default, belongs-to relationships are converted into IDs when inserted into the JSON hash.

IDs

serialize takes an options hash with a single option: includeId. If this option is true, serialize will, by default include the ID in the JSON object it builds.

The adapter passes in includeId: true when serializing a record for createRecord, but not for updateRecord.

Customization

Your server may expect a different JSON format than the built-in serialization format.

In that case, you can implement serialize yourself and return a JSON hash of your choosing.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
App.PostSerializer = DS.JSONSerializer.extend({
  serialize: function(post, options) {
    var json = {
      POST_TTL: post.get('title'),
      POST_BDY: post.get('body'),
      POST_CMS: post.get('comments').mapBy('id')
    }

    if (options.includeId) {
      json.POST_ID_ = post.get('id');
    }

    return json;
  }
});

Customizing an App-Wide Serializer

If you want to define a serializer for your entire application, you'll probably want to use eachAttribute and eachRelationship on the record.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
App.ApplicationSerializer = DS.JSONSerializer.extend({
  serialize: function(record, options) {
    var json = {};

    record.eachAttribute(function(name) {
      json[serverAttributeName(name)] = record.get(name);
    })

    record.eachRelationship(function(name, relationship) {
      if (relationship.kind === 'hasMany') {
        json[serverHasManyName(name)] = record.get(name).mapBy('id');
      }
    });

    if (options.includeId) {
      json.ID_ = record.get('id');
    }

    return json;
  }
});

function serverAttributeName(attribute) {
  return attribute.underscore().toUpperCase();
}

function serverHasManyName(name) {
  return serverAttributeName(name.singularize()) + "_IDS";
}

This serializer will generate JSON that looks like this:

1
2
3
4
5
{
  "TITLE": "Rails is omakase",
  "BODY": "Yep. Omakase.",
  "COMMENT_IDS": [ 1, 2, 3 ]
}

Tweaking the Default JSON

If you just want to do some small tweaks on the default JSON, you can call super first and make the tweaks on the returned JSON.

1
2
3
4
5
6
7
8
9
10
App.PostSerializer = DS.JSONSerializer.extend({
  serialize: function(record, options) {
    var json = this._super.apply(this, arguments);

    json.subject = json.title;
    delete json.title;

    return json;
  }
});

Parameters:

record subclass of DS.Model
options Object

Returns:

Object
json

serializeAttribute

(record, json, key, attribute)

serializeAttribute can be used to customize how DS.attr properties are serialized

For example if you wanted to ensure all your attributes were always serialized as properties on an attributes object you could write:

1
2
3
4
5
6
App.ApplicationSerializer = DS.JSONSerializer.extend({
  serializeAttribute: function(record, json, key, attributes) {
    json.attributes = json.attributes || {};
    this._super(record, json.attributes, key, attributes);
  }
});

Parameters:

record DS.Model
json Object
key String
attribute Object

serializeBelongsTo

(record, json, relationship)

serializeBelongsTo can be used to customize how DS.belongsTo properties are serialized.

Example

1
2
3
4
5
6
7
8
9
10
11
App.PostSerializer = DS.JSONSerializer.extend({
  serializeBelongsTo: function(record, json, relationship) {
    var key = relationship.key;

    var belongsTo = get(record, key);

    key = this.keyForRelationship ? this.keyForRelationship(key, "belongsTo") : key;

    json[key] = Ember.isNone(belongsTo) ? belongsTo : belongsTo.toJSON();
  }
});

Parameters:

record DS.Model
json Object
relationship Object

serializeHasMany

(record, json, relationship)

serializeHasMany can be used to customize how DS.hasMany properties are serialized.

Example

1
2
3
4
5
6
7
8
9
10
App.PostSerializer = DS.JSONSerializer.extend({
  serializeHasMany: function(record, json, relationship) {
    var key = relationship.key;
    if (key === 'comments') {
      return;
    } else {
      this._super.apply(this, arguments);
    }
  }
});

Parameters:

record DS.Model
json Object
relationship Object

serializeIntoHash

(hash, type, record, options)

You can use this method to customize how a serialized record is added to the complete JSON hash to be sent to the server. By default the JSON Serializer does not namespace the payload and just sends the raw serialized JSON object. If your server expects namespaced keys, you should consider using the RESTSerializer. Otherwise you can override this method to customize how the record is added to the hash.

For example, your server may expect underscored root objects.

1
2
3
4
5
6
App.ApplicationSerializer = DS.RESTSerializer.extend({
  serializeIntoHash: function(data, type, record, options) {
    var root = Ember.String.decamelize(type.typeKey);
    data[root] = this.serialize(record, options);
  }
});

Parameters:

hash Object
type subclass of DS.Model
record DS.Model
options Object

serializePolymorphicType

(record, json, relationship)

You can use this method to customize how polymorphic objects are serialized. Objects are considered to be polymorphic if {polymorphic: true} is pass as the second argument to the DS.belongsTo function.

Example

1
2
3
4
5
6
7
8
9
10
11
12
13
App.CommentSerializer = DS.JSONSerializer.extend({
  serializePolymorphicType: function(record, json, relationship) {
    var key = relationship.key,
        belongsTo = get(record, key);
    key = this.keyForAttribute ? this.keyForAttribute(key) : key;

    if (Ember.isNone(belongsTo)) {
      json[key + "_type"] = null;
    } else {
      json[key + "_type"] = belongsTo.constructor.typeKey;
    }
  }
});

Parameters:

record DS.Model
json Object
relationship Object

transformFor

(attributeType, skipAssertion) DS.Transform private

Parameters:

attributeType String
skipAssertion Boolean

Returns:

DS.Transform
transform
Show:

attrs

{Object}

The attrs object can be used to declare a simple mapping between property names on DS.Model records and payload keys in the serialized JSON object representing the record. An object with the property key can also be used to designate the attribute's key on the response payload.

Example

1
2
3
4
5
6
7
8
9
10
11
12
13
App.Person = DS.Model.extend({
  firstName: DS.attr('string'),
  lastName: DS.attr('string'),
  occupation: DS.attr('string'),
  admin: DS.attr('boolean')
});

App.PersonSerializer = DS.JSONSerializer.extend({
  attrs: {
    admin: 'is_admin',
    occupation: {key: 'career'}
  }
});

You can also remove attributes by setting the serialize key to false in your mapping object.

Example

1
2
3
4
5
6
App.PersonSerializer = DS.JSONSerializer.extend({
  attrs: {
    admin: {serialize: false},
    occupation: {key: 'career'}
  }
});

When serialized:

1
2
3
{
  "career": "magician"
}

Note that the admin is now not included in the payload.

primaryKey

{String}

The primaryKey is used when serializing and deserializing data. Ember Data always uses the id property to store the id of the record. The external source may not always follow this convention. In these cases it is useful to override the primaryKey property to match the primaryKey of your external store.

Example

1
2
3
App.ApplicationSerializer = DS.JSONSerializer.extend({
  primaryKey: '_id'
});

Default: 'id'