Class DS.JSONAPISerializer

Ember Data 2.0 Serializer:

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.

JSONAPISerializer supports the http://jsonapi.org/ spec and is the serializer recommended by Ember Data.

This serializer normalizes a JSON API payload that looks like:

app/models/player.js
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import DS from 'ember-data';

export default DS.Model.extend({
  name: DS.attr('string'),
  skill: DS.attr('string'),
  gamesPlayed: DS.attr('number'),
  club: DS.belongsTo('club')
});
app/models/club.js
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import DS from 'ember-data';

export default DS.Model.extend({
  name: DS.attr('string'),
  location: DS.attr('string'),
  players: DS.hasMany('player')
});
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  {
    "data": [
      {
        "attributes": {
          "name": "Benfica",
          "location": "Portugal"
        },
        "id": "1",
        "relationships": {
          "players": {
            "data": [
              {
                "id": "3",
                "type": "players"
              }
            ]
          }
        },
        "type": "clubs"
      }
    ],
    "included": [
      {
        "attributes": {
          "name": "Eusebio Silva Ferreira",
          "skill": "Rocket shot",
          "games-played": 431
        },
        "id": "3",
        "relationships": {
          "club": {
            "data": {
              "id": "1",
              "type": "clubs"
            }
          }
        },
        "type": "players"
      }
    ]
  }

to the format that the Ember Data store expects.

Customizing meta

Since a JSON API Document can have meta defined in multiple locations you can use the specific serializer hooks if you need to customize the meta.

One scenario would be to camelCase the meta keys of your payload. The example below shows how this could be done using normalizeArrayResponse and extractRelationship.

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export default JSONAPISerializer.extend({
  normalizeArrayResponse(store, primaryModelClass, payload, id, requestType) {
    let normalizedDocument = this._super(...arguments);

    // Customize document meta
    normalizedDocument.meta = camelCaseKeys(normalizedDocument.meta);

    return normalizedDocument;
  },

  extractRelationship(relationshipHash) {
    let normalizedRelationship = this._super(...arguments);

    // Customize relationship meta
    normalizedRelationship.meta = camelCaseKeys(normalizedRelationship.meta);

    return normalizedRelationship;
  }
});

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;
    }
  }
});
relationshipModelName
Object
relationshipHash
Object
relationshipOptions
Object
returns
Object

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

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

relationshipOptions is a hash which contains more information about the polymorphic relationship which should be extracted:

  • resourceHash complete hash of the resource the relationship should be extracted from
  • relationshipKey key under which the value for the relationship is extracted from the resourceHash
  • relationshipMeta meta information about the relationship
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. By default JSONAPISerializer follows the format used on the examples of http://jsonapi.org/format and uses dashes as the word separator in the JSON attribute keys.

This behaviour can be easily customized by extending this method.

Example

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import DS from 'ember-data';
import { dasherize } from '@ember/string';

export default DS.JSONAPISerializer.extend({
  keyForAttribute(attr, method) {
    return dasherize(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

keyForRelationship can be used to define a custom key when serializing and deserializing relationship properties. By default JSONAPISerializer follows the format used on the examples of http://jsonapi.org/format and uses dashes as word separators in relationship properties.

This behaviour can be easily customized by extending this method.

Example

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 import DS from 'ember-data';
 import { underscore } from '@ember/string';

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

Dasherizes and singularizes the model name in the payload to match the format Ember Data uses internally for the model name.

For example the key posts would be converted to post and the key studentAssesments would be converted to student-assesment.

typeClass
DS.Model
hash
Object
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.

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

Example

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import DS from 'ember-data';
import { underscore } from '@ember/string';
import { get } from '@ember/object';

export default DS.JSONSerializer.extend({
  normalize(typeClass, hash) {
    var fields = get(typeClass, 'fields');

    fields.forEach(function(field) {
      var payloadField = underscore(field);
      if (field === payloadField) { return; }

      hash[field] = hash[payloadField];
      delete hash[payloadField];
    });

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

Converts the model name to a pluralized version of the model name.

For example post would be converted to posts and student-assesment would be converted to student-assesments.

store
DS.Store
payload
Object
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:

app/models/comment.js
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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.JSONSerializer.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';
import { singularize } from 'ember-inflector';

export default DS.JSONSerializer.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(singularize(name)) + "_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.JSONSerializer.extend({
  serialize(snapshot, options) {
    var json = this._super(...arguments);

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

    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';
import { isNone } from '@ember/utils';

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] = 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);
    }
  }
});
hash
Object
typeClass
DS.Model
snapshot
DS.Snapshot
options
Object

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. The hash property should be modified by reference.

For example, your server may expect underscored root objects.

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import DS from 'ember-data';
import { decamelize } from '@ember/string';

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

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

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import DS from 'ember-data';
import { isNone } from '@ember/utils';

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

    key = this.keyForAttribute ? this.keyForAttribute(key, 'serialize') : key;

    if (isNone(belongsTo)) {
      json[key + '_type'] = null;
    } else {
      json[key + '_type'] = belongsTo.modelName;
    }
  }
});
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

By default only many-to-many and many-to-none relationships are serialized. This could be configured per relationship by Serializer's attrs object.