DS.RESTSerializer

Normally, applications will use the RESTSerializer by implementing the normalize method.

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 Firebase, 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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import DS from 'ember-data';

export default DS.RESTSerializer.extend({
  keyForAttribute(attr, method) {
    return Ember.String.underscore(attr).toUpperCase();
  }
});

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

Show:

modelClass
Object
resourceHash
Object
returns
Object

Returns the resource's attributes formatted as a JSON-API "attributes object".

http://jsonapi.org/format/#document-resource-object-attributes

store
DS.Store
typeClass
DS.Model
payload
Object
id
(String|Number)
returns
Object
json The deserialized errors

extractErrors is used to extract model errors when a call to DS.Model#save fails with an InvalidError. By default Ember Data expects error information to be located on the errors property of the payload object.

This serializer expects this errors object to be an Array similar to the following, compliant with the JSON-API specification:

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{
  "errors": [
    {
      "detail": "This username is already taken!",
      "source": {
        "pointer": "data/attributes/username"
      }
    }, {
      "detail": "Doesn't look like a valid email.",
      "source": {
        "pointer": "data/attributes/email"
      }
    }
  ]
}

The key detail provides a textual description of the problem. Alternatively, the key title can be used for the same purpose.

The nested keys source.pointer detail which specific element of the request data was invalid.

Note that JSON-API also allows for object-level errors to be placed in an object with pointer data, signifying that the problem cannot be traced to a specific attribute:

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{
  "errors": [
    {
      "detail": "Some generic non property error message",
      "source": {
        "pointer": "data"
      }
    }
  ]
}

When turn into a DS.Errors object, you can read these errors through the property base:

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{{#each model.errors.base as |error|}}
  <div class="error">
    {{error.message}}
  </div>
{{/each}}

Example of alternative implementation, overriding the default behavior to deal with a different format of errors:

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import DS from 'ember-data';

export default DS.JSONSerializer.extend({
  extractErrors(store, typeClass, payload, id) {
    if (payload && typeof payload === 'object' && payload._problems) {
      payload = payload._problems;
      this.normalizeErrors(typeClass, payload);
    }
    return payload;
  }
});
modelClass
Object
resourceHash
Object
returns
String

Returns the resource's ID.

store
DS.Store
modelClass
DS.Model
payload
Object

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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import DS from 'ember-data';

export default DS.JSONSerializer.extend({
  extractMeta(store, typeClass, payload) {
    if (payload && payload.hasOwnProperty('_pagination')) {
      let meta = payload._pagination;
      delete payload._pagination;
      return meta;
    }
  }
});
relationshipType
Object
relationshipHash
Object
relationshipOptions
Object
returns
Object

You can use this method to customize how a polymorphic relationship should be extracted.

relationshipModelName
Object
relationshipHash
Object
returns
Object

Returns a relationship formatted as a JSON-API "relationship object".

http://jsonapi.org/format/#document-resource-object-relationships

modelClass
Object
resourceHash
Object
returns
Object

Returns the resource's relationships formatted as a JSON-API "relationships object".

http://jsonapi.org/format/#document-resource-object-relationships

key
String
method
String
returns
String
normalized key

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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import DS from 'ember-data';

export default DS.RESTSerializer.extend({
  keyForAttribute(attr, method) {
    return Ember.String.underscore(attr).toUpperCase();
  }
});
key
String
kind
String
`belongsTo` or `hasMany`
returns
String
normalized key

keyForLink can be used to define a custom key when deserializing link properties.

key
String
typeClass
String
method
String
returns
String
normalized key

keyForPolymorphicType can be used to define a custom key when serializing and deserializing a polymorphic type. By default, the returned key is ${key}Type.

Example

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 import DS from 'ember-data';

 export default DS.RESTSerializer.extend({
   keyForPolymorphicType(key, relationship) {
     var relationshipKey = this.keyForRelationship(key);

     return 'type-' + relationshipKey;
   }
 });
key
String
typeClass
String
method
String
returns
String
normalized key

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

Example

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 import DS from 'ember-data';

 export default DS.JSONSerializer.extend({
   keyForRelationship(key, relationship, method) {
     return 'rel_' + Ember.String.underscore(key);
   }
 });
key
String
returns
String
the model's modelName

This method is used to convert each JSON root key in the payload into a modelName that it can use to look up the appropriate model for that part of the payload.

For example, your server may send a model name that does not correspond with the name of the model in your app. Let's take a look at an example model, and an example payload:

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import DS from 'ember-data';

export default DS.Model.extend({
});
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  {
    "blog/post": {
      "id": "1
    }
  }

Ember Data is going to normalize the payload's root key for the modelName. As a result, it will try to look up the "blog/post" model. Since we don't have a model called "blog/post" (or a file called app/models/blog/post.js in ember-cli), Ember Data will throw an error because it cannot find the "blog/post" model.

Since we want to remove this namespace, we can define a serializer for the application that will remove "blog/" from the payload key whenver it's encountered by Ember Data:

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import DS from 'ember-data';

export default DS.RESTSerializer.extend({
  modelNameFromPayloadKey(payloadKey) {
    if (payloadKey === 'blog/post') {
      return this._super(payloadKey.replace('blog/', ''));
    } else {
     return this._super(payloadKey);
    }
  }
});

After refreshing, Ember Data will appropriately look up the "post" model.

By default the modelName for a model is its name in dasherized form. This means that a payload key like "blogPost" would be normalized to "blog-post" when Ember Data looks up the model. Usually, Ember Data can use the correct inflection to do this for you. Most of the time, you won't need to override modelNameFromPayloadKey for this purpose.

payloadType
String
type from payload
returns
String
modelName

modelNameFromPayloadType can be used to change the mapping for a DS model name, taken from the value in the payload.

Say your API namespaces the type of a model and returns the following payload for the post model, which has a polymorphic user relationship:

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// GET /api/posts/1
{
  "post": {
    "id": 1,
    "user": 1,
    "userType: "api::v1::administrator"
  }
}

By overwriting modelNameFromPayloadType you can specify that the administrator model should be used:

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import DS from 'ember-data';

export default DS.RESTSerializer.extend({
  modelNameFromPayloadType(payloadType) {
    return payloadType.replace('api::v1::', '');
  }
});

By default the modelName for a model is its name in dasherized form. Usually, Ember Data can use the correct inflection to do this for you. Most of the time, you won't need to override modelNameFromPayloadType for this purpose.

Also take a look at payloadTypeFromModelName to customize how the type of a record should be serialized.

modelClass
DS.Model
resourceHash
Object
prop
String
returns
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. You will only need to implement normalize and manipulate the payload as desired.

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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import DS from 'ember-data';

export default DS.RESTSerializer.extend({
  normalize(model, hash, prop) {
    if (prop === 'comments') {
      hash.id = hash._id;
      delete hash._id;
    }

    return this._super(...arguments);
  }
});

On each call to the normalize method, the third parameter (prop) is always one of the keys that were in the original payload or in the result of another normalization as normalizeResponse.

typeClass
DS.Model
hash
Object
returns
Object

The normalize method is used to convert a payload received from your external data source into the normalized form store.push() expects. You should override this method, munge the hash and return the normalized payload.

Example:

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Serializer.extend({
  normalize(modelClass, resourceHash) {
    var data = {
      id:            resourceHash.id,
      type:          modelClass.modelName,
      attributes:    resourceHash
    };
    return { data: data };
  }
})
store
DS.Store
primaryModelClass
DS.Model
payload
Object
id
String|Number
requestType
String
returns
Object
JSON-API Document
store
DS.Store
primaryModelClass
DS.Model
payload
Object
id
String|Number
requestType
String
returns
Object
JSON-API Document
store
DS.Store
primaryModelClass
DS.Model
payload
Object
id
String|Number
requestType
String
returns
Object
JSON-API Document
store
DS.Store
primaryModelClass
DS.Model
payload
Object
id
String|Number
requestType
String
returns
Object
JSON-API Document
store
DS.Store
primaryModelClass
DS.Model
payload
Object
id
String|Number
requestType
String
returns
Object
JSON-API Document
store
DS.Store
primaryModelClass
DS.Model
payload
Object
id
String|Number
requestType
String
returns
Object
JSON-API Document
store
DS.Store
primaryModelClass
DS.Model
payload
Object
id
String|Number
requestType
String
returns
Object
JSON-API Document
store
DS.Store
primaryModelClass
DS.Model
payload
Object
id
String|Number
requestType
String
returns
Object
JSON-API Document
store
DS.Store
primaryModelClass
DS.Model
payload
Object
id
String|Number
requestType
String
returns
Object
JSON-API Document
store
DS.Store
primaryModelClass
DS.Model
payload
Object
id
String|Number
requestType
String
returns
Object
JSON-API Document
store
DS.Store
primaryModelClass
DS.Model
payload
Object
id
String|Number
requestType
String
returns
Object
JSON-API Document

The normalizeResponse method is used to normalize a payload from the server to a JSON-API Document.

http://jsonapi.org/format/#document-structure

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

To override this method with a custom one, make sure to call return this._super(store, primaryModelClass, payload, id, requestType) with your pre-processed data.

Here's an example of using normalizeResponse manually:

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socket.on('message', function(message) {
  var data = message.data;
  var modelClass = store.modelFor(data.modelName);
  var serializer = store.serializerFor(data.modelName);
  var normalized = serializer.normalizeSingleResponse(store, modelClass, data, data.id);

  store.push(normalized);
});
store
DS.Store
primaryModelClass
DS.Model
payload
Object
id
String|Number
requestType
String
returns
Object
JSON-API Document
store
DS.Store
primaryModelClass
DS.Model
payload
Object
id
String|Number
requestType
String
returns
Object
JSON-API Document
store
DS.Store
primaryModelClass
DS.Model
payload
Object
id
String|Number
requestType
String
returns
Object
JSON-API Document
modelName
String
returns
String

You can use payloadKeyFromModelName to override the root key for an outgoing request. By default, the RESTSerializer returns a camelized version of the model's name.

For a model called TacoParty, its modelName would be the string taco-party. The RESTSerializer will send it to the server with tacoParty as the root key in the JSON payload:

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{
  "tacoParty": {
    "id": "1",
    "location": "Matthew Beale's House"
  }
}

For example, your server may expect dasherized root objects:

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import DS from 'ember-data';

export default DS.RESTSerializer.extend({
  payloadKeyFromModelName(modelName) {
    return Ember.String.dasherize(modelName);
  }
});

Given a TacoParty model, calling save on it would produce an outgoing request like:

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{
  "taco-party": {
    "id": "1",
    "location": "Matthew Beale's House"
  }
}
modelName
String
modelName from the record
returns
String
payloadType

payloadTypeFromModelName can be used to change the mapping for the type in the payload, taken from the model name.

Say your API namespaces the type of a model and expects the following payload when you update the post model, which has a polymorphic user relationship:

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// POST /api/posts/1
{
  "post": {
    "id": 1,
    "user": 1,
    "userType": "api::v1::administrator"
  }
}

By overwriting payloadTypeFromModelName you can specify that the namespaces model name for the administrator should be used:

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import DS from 'ember-data';

export default DS.RESTSerializer.extend({
  payloadTypeFromModelName(modelName) {
    return 'api::v1::' + modelName;
  }
});

By default the payload type is the camelized model name. Usually, Ember Data can use the correct inflection to do this for you. Most of the time, you won't need to override payloadTypeFromModelName for this purpose.

Also take a look at modelNameFromPayloadType to customize how the model name from should be mapped from the payload.

store
DS.Store
payload
Object

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.

snapshot
DS.Snapshot
options
Object
returns
Object
json

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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import DS from 'ember-data';

export default 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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import DS from 'ember-data';

export default DS.RESTSerializer.extend({
  serialize(snapshot, options) {
    var json = {
      POST_TTL: snapshot.attr('title'),
      POST_BDY: snapshot.attr('body'),
      POST_CMS: snapshot.hasMany('comments', { ids: true })
    };

    if (options.includeId) {
      json.POST_ID_ = snapshot.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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import DS from 'ember-data';

export default DS.RESTSerializer.extend({
  serialize(snapshot, options) {
    var json = {};

    snapshot.eachAttribute(function(name) {
      json[serverAttributeName(name)] = snapshot.attr(name);
    });

    snapshot.eachRelationship(function(name, relationship) {
      if (relationship.kind === 'hasMany') {
        json[serverHasManyName(name)] = snapshot.hasMany(name, { ids: true });
      }
    });

    if (options.includeId) {
      json.ID_ = snapshot.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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import DS from 'ember-data';

export default DS.RESTSerializer.extend({
  serialize(snapshot, options) {
    var json = this._super(snapshot, options);

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

    return json;
  }
});
snapshot
DS.Snapshot
options
Object
returns
Object

The serialize method is used when a record is saved in order to convert the record into the form that your external data source expects.

serialize takes an optional options hash with a single option:

  • includeId: If this is true, serialize should include the ID in the serialized object it builds.

Example:

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Serializer.extend({
  serialize(snapshot, options) {
    var json = {
      id: snapshot.id
    };

    snapshot.eachAttribute((key, attribute) => {
      json[key] = snapshot.attr(key);
    });

    snapshot.eachRelationship((key, relationship) => {
      if (relationship.kind === 'belongsTo') {
        json[key] = snapshot.belongsTo(key, { id: true });
      } else if (relationship.kind === 'hasMany') {
        json[key] = snapshot.hasMany(key, { ids: true });
      }
    });

    return json;
  },
});
snapshot
DS.Snapshot
json
Object
key
String
attribute
Object

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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import DS from 'ember-data';

export default DS.JSONSerializer.extend({
  serializeAttribute(snapshot, json, key, attributes) {
    json.attributes = json.attributes || {};
    this._super(snapshot, json.attributes, key, attributes);
  }
});
snapshot
DS.Snapshot
json
Object
relationship
Object

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

Example

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import DS from 'ember-data';

export default DS.JSONSerializer.extend({
  serializeBelongsTo(snapshot, json, relationship) {
    var key = relationship.key;
    var belongsTo = snapshot.belongsTo(key);

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

    json[key] = Ember.isNone(belongsTo) ? belongsTo : belongsTo.record.toJSON();
  }
});
snapshot
DS.Snapshot
json
Object
relationship
Object

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

Example

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import DS from 'ember-data';

export default DS.JSONSerializer.extend({
  serializeHasMany(snapshot, json, relationship) {
    var key = relationship.key;
    if (key === 'comments') {
      return;
    } else {
      this._super(...arguments);
    }
  }
});
snapshot
DS.Snapshot
json
Object
primaryKey
String

serializeId can be used to customize how id is serialized For example, your server may expect integer datatype of id

By default the snapshot's id (String) is set on the json hash via json[primaryKey] = snapshot.id.

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import DS from 'ember-data';

export default DS.JSONSerializer.extend({
serializeId(snapshot, json, primaryKey) {
    var id = snapshot.id;
    json[primaryKey] = parseInt(id, 10);
  }
});
hash
Object
typeClass
DS.Model
snapshot
DS.Snapshot
options
Object

You can use this method to customize the root keys serialized into the JSON. The hash property should be modified by reference (possibly using something like _.extend) By default the REST Serializer sends the modelName of a model, which is a camelized version of the name.

For example, your server may expect underscored root objects.

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import DS from 'ember-data';

export default DS.RESTSerializer.extend({
  serializeIntoHash(data, type, record, options) {
    var root = Ember.String.decamelize(type.modelName);
    data[root] = this.serialize(record, options);
  }
});
snapshot
DS.Snapshot
json
Object
relationship
Object

You can use this method to customize how polymorphic objects are serialized. By default the REST Serializer creates the key by appending Type to the attribute and value from the model's camelcased model name.

snapshot
DS.Snapshot
key
String
relationshipType
String
returns
Boolean
true if the hasMany relationship should be serialized

Check if the given hasMany relationship should be serialized