DS.RESTSerializer Class packages/ember-data/lib/serializers/rest_serializer.js:17

Normally, applications will use the RESTSerializer by implementing the normalize method and individual normalizations under normalizeHash.

This allows you to do whatever kind of munging you need, and is especially useful if your server is inconsistent and you need to do munging differently for many different kinds of responses.

See the normalize documentation for more information.

Across the Board Normalization

There are also a number of hooks that you might find useful to define across-the-board rules for your payload. These rules will be useful if your server is consistent, or if you're building an adapter for an infrastructure service, like Parse, and want to encode service conventions.

For example, if all of your keys are underscored and all-caps, but otherwise consistent with the names you use in your models, you can implement across-the-board rules for how to convert an attribute name in your model to a key in your JSON.

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

You can also implement keyForRelationship, which takes the name of the relationship as the first parameter, and the kind of relationship (hasMany or belongsTo) as the second parameter.

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

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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, primaryType, payload) Array

Called when the server has returned a payload representing multiple records, such as in response to a findAll or findQuery.

It is your opportunity to clean up the server's response into the normalized form expected by Ember Data.

If you want, you can just restructure the top-level of your payload, and do more fine-grained normalization in the normalize method.

For example, if you have a payload like this in response to a request for all posts:

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{
  "_embedded": {
    "post": [{
      "id": 1,
      "title": "Rails is omakase"
    }, {
      "id": 2,
      "title": "The Parley Letter"
    }],
    "comment": [{
      "_id": 1,
      "comment_title": "Rails is unagi"
      "post_id": 1
    }, {
      "_id": 2,
      "comment_title": "Don't tread on me",
      "post_id": 2
    }]
  }
}

You could implement a serializer that looks like this to get your payload into shape:

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App.PostSerializer = DS.RESTSerializer.extend({
  // First, restructure the top-level so it's organized by type
  // and the comments are listed under a post's `comments` key.
  extractArray: function(store, type, payload) {
    var posts = payload._embedded.post;
    var comments = [];
    var postCache = {};

    posts.forEach(function(post) {
      post.comments = [];
      postCache[post.id] = post;
    });

    payload._embedded.comment.forEach(function(comment) {
      comments.push(comment);
      postCache[comment.post_id].comments.push(comment);
      delete comment.post_id;
    });

    payload = { comments: comments, posts: payload };

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

  normalizeHash: {
    // Next, normalize individual comments, which (after `extract`)
    // are now located under `comments`
    comments: function(hash) {
      hash.id = hash._id;
      hash.title = hash.comment_title;
      delete hash._id;
      delete hash.comment_title;
      return hash;
    }
  }
})

When you call super from your own implementation of extractArray, the built-in implementation will find the primary array in your normalized payload and push the remaining records into the store.

The primary array is the array found under posts.

The primary record has special meaning when responding to findQuery or findHasMany. In particular, the primary array will become the list of records in the record array that kicked off the request.

If your primary array contains secondary (embedded) records of the same type, you cannot place these into the primary array posts. Instead, place the secondary items into an underscore prefixed property _posts, which will push these items into the store and will not affect the resulting query.

Parameters:

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

Returns:

Array
The primary array that was returned in response to the original query.

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

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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, primaryType, payload, recordId) Object

Called when the server has returned a payload representing a single record, such as in response to a find or save.

It is your opportunity to clean up the server's response into the normalized form expected by Ember Data.

If you want, you can just restructure the top-level of your payload, and do more fine-grained normalization in the normalize method.

For example, if you have a payload like this in response to a request for post 1:

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{
  "id": 1,
  "title": "Rails is omakase",

  "_embedded": {
    "comment": [{
      "_id": 1,
      "comment_title": "FIRST"
    }, {
      "_id": 2,
      "comment_title": "Rails is unagi"
    }]
  }
}

You could implement a serializer that looks like this to get your payload into shape:

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App.PostSerializer = DS.RESTSerializer.extend({
  // First, restructure the top-level so it's organized by type
  extractSingle: function(store, type, payload, id) {
    var comments = payload._embedded.comment;
    delete payload._embedded;

    payload = { comments: comments, post: payload };
    return this._super(store, type, payload, id);
  },

  normalizeHash: {
    // Next, normalize individual comments, which (after `extract`)
    // are now located under `comments`
    comments: function(hash) {
      hash.id = hash._id;
      hash.title = hash.comment_title;
      delete hash._id;
      delete hash.comment_title;
      return hash;
    }
  }
})

When you call super from your own implementation of extractSingle, the built-in implementation will find the primary record in your normalized payload and push the remaining records into the store.

The primary record is the single hash found under post or the first element of the posts array.

The primary record has special meaning when the record is being created for the first time or updated (createRecord or updateRecord). In particular, it will update the properties of the record that was saved.

Parameters:

store DS.Store
primaryType subclass of DS.Model
payload Object
recordId String

Returns:

Object
the primary response to the original request

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

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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

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 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, prop) 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.

For example, if you have a payload that looks like this:

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{
  "post": {
    "id": 1,
    "title": "Rails is omakase",
    "comments": [ 1, 2 ]
  },
  "comments": [{
    "id": 1,
    "body": "FIRST"
  }, {
    "id": 2,
    "body": "Rails is unagi"
  }]
}

The normalize method will be called three times:

  • With App.Post, "posts" and { id: 1, title: "Rails is omakase", ... }
  • With App.Comment, "comments" and { id: 1, body: "FIRST" }
  • With App.Comment, "comments" and { id: 2, body: "Rails is unagi" }

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

If you want to do normalizations specific to some part of the payload, you can specify those under normalizeHash.

For example, if the IDs under "comments" are provided as _id instead of id, you can specify how to normalize just the comments:

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App.PostSerializer = DS.RESTSerializer.extend({
  normalizeHash: {
    comments: function(hash) {
      hash.id = hash._id;
      delete hash._id;
      return hash;
    }
  }
});

The key under normalizeHash is just the original key that was in the original payload.

Parameters:

type subclass of DS.Model
hash Object
prop String

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:

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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

pushPayload

(store, payload)

This method allows you to push a payload containing top-level collections of records organized per type.

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{
  "posts": [{
    "id": "1",
    "title": "Rails is omakase",
    "author", "1",
    "comments": [ "1" ]
  }],
  "comments": [{
    "id": "1",
    "body": "FIRST"
  }],
  "users": [{
    "id": "1",
    "name": "@d2h"
  }]
}

It will first normalize the payload, so you can use this to push in data streaming in from your server structured the same way that fetches and saves are structured.

Parameters:

store DS.Store
payload Object

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:

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App.Comment = DS.Model.extend({
  title: DS.attr(),
  body: DS.attr(),

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

The default serialization would create a JSON object like:

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{
  "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.

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App.PostSerializer = DS.RESTSerializer.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.

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App.ApplicationSerializer = DS.RESTSerializer.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:

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{
  "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.

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App.PostSerializer = DS.RESTSerializer.extend({
  serialize: function(record, options) {
    var json = this._super(record, options);

    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:

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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

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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

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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 the root keys serialized into the JSON. By default the REST Serializer sends the typeKey of a model, which is a camelized version of the name.

For example, your server may expect underscored root objects.

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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. By default the JSON Serializer creates the key by appending Type to the attribute and value from the model's camelcased model name.

Parameters:

record DS.Model
json Object
relationship Object

transformFor

(attributeType, skipAssertion) DS.Transform private

Parameters:

attributeType String
skipAssertion Boolean

Returns:

DS.Transform
transform

typeForRoot

(key) String

This method is used to convert each JSON root key in the payload into a typeKey that it can use to look up the appropriate model for that part of the payload. By default the typeKey for a model is its name in camelCase, so if your JSON root key is 'fast-car' you would use typeForRoot to convert it to 'fastCar' so that Ember Data finds the FastCar model.

If you diverge from this norm you should also consider changes to store._normalizeTypeKey as well.

For example, your server may return prefixed root keys like so:

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{
  "response-fast-car": {
    "id": "1",
    "name": "corvette"
  }
}

In order for Ember Data to know that the model corresponding to the 'response-fast-car' hash is FastCar (typeKey: 'fastCar'), you can override typeForRoot to convert 'response-fast-car' to 'fastCar' like so:

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App.ApplicationSerializer = DS.RESTSerializer.extend({
  typeForRoot: function(root) {
    // 'response-fast-car' should become 'fast-car'
    var subRoot = root.substring(9);

    // _super normalizes 'fast-car' to 'fastCar'
    return this._super(subRoot);
  }
});

Parameters:

key String

Returns:

String
the model's typeKey
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

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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

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

When serialized:

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{
  "career": "magician"
}

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

normalizeHash

{Object}

If you want to do normalizations specific to some part of the payload, you can specify those under normalizeHash.

For example, given the following json where the the IDs under "comments" are provided as _id instead of id.

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{
  "post": {
    "id": 1,
    "title": "Rails is omakase",
    "comments": [ 1, 2 ]
  },
  "comments": [{
    "_id": 1,
    "body": "FIRST"
  }, {
    "_id": 2,
    "body": "Rails is unagi"
  }]
}

You use normalizeHash to normalize just the comments:

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App.PostSerializer = DS.RESTSerializer.extend({
  normalizeHash: {
    comments: function(hash) {
      hash.id = hash._id;
      delete hash._id;
      return hash;
    }
  }
});

The key under normalizeHash is usually just the original key that was in the original payload. However, key names will be impacted by any modifications done in the normalizePayload method. The DS.RESTSerializer's default implementation makes no changes to the payload keys.

Default: undefined

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

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

Default: 'id'