JSONAPISerializer Class
⚠️ This is LEGACY documentation for a feature that is no longer encouraged to be used. If starting a new app or thinking of implementing a new adapter, consider writing a Handler instead to be used with the RequestManager
In EmberData 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:
import Model, { attr, belongsTo } from '@ember-data/model';
export default class Player extends Model {
@attr('string') name;
@attr('string') skill;
@attr('number') gamesPlayed;
@belongsTo('club') club;
}
import Model, { attr, hasMany } from '@ember-data/model';
export default class Club extends Model {
@attr('string') name;
@attr('string') location;
@hasMany('player') players;
}
{
"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
.
import JSONAPISerializer from '@ember-data/serializer/json-api';
export default class ApplicationSerializer extends JSONAPISerializer {
normalizeArrayResponse(store, primaryModelClass, payload, id, requestType) {
let normalizedDocument = super.normalizeArrayResponse(...arguments);
// Customize document meta
normalizedDocument.meta = camelCaseKeys(normalizedDocument.meta);
return normalizedDocument;
}
extractRelationship(relationshipHash) {
let normalizedRelationship = super.extractRelationship(...arguments);
// Customize relationship meta
normalizedRelationship.meta = camelCaseKeys(normalizedRelationship.meta);
return normalizedRelationship;
}
}
Item Index
Methods
- _canSerialize
- _extractType
- _getMappedKey
- _mustSerialize
- _normalizeDocumentHelper
- _normalizeRelationshipDataHelper
- _normalizeResourceHelper
- _normalizeResponse
- applyTransforms
- extractAttributes
- extractErrors
- extractId
- extractMeta
- extractPolymorphicRelationship
- extractRelationship
- extractRelationships
- keyForAttribute
- keyForLink
- keyForRelationship
- modelNameFromPayloadKey
- normalize
- normalizeArrayResponse
- normalizeCreateRecordResponse
- normalizeDeleteRecordResponse
- normalizeFindAllResponse
- normalizeFindBelongsToResponse
- normalizeFindHasManyResponse
- normalizeFindManyResponse
- normalizeFindRecordResponse
- normalizeQueryRecordResponse
- normalizeQueryResponse
- normalizeRelationships
- normalizeResponse
- normalizeSaveResponse
- normalizeSingleResponse
- normalizeUpdateRecordResponse
- normalizeUsingDeclaredMapping
- payloadKeyFromModelName
- pushPayload
- serialize
- serializeAttribute
- serializeBelongsTo
- serializeHasMany
- serializeIntoHash
- serializePolymorphicType
- shouldSerializeHasMany
- transformFor
Properties
Methods
_canSerialize
-
key
key
can be serialized
Parameters:
-
key
String
Returns:
_extractType
-
modelClass
-
resourceHash
Parameters:
-
modelClass
Model -
resourceHash
Object
Returns:
_getMappedKey
-
key
attr
mapping
passed to the serializer.
Parameters:
-
key
String
Returns:
_mustSerialize
-
key
Parameters:
-
key
String
Returns:
_normalizeDocumentHelper
-
documentHash
Parameters:
-
documentHash
Object
Returns:
_normalizeRelationshipDataHelper
-
relationshipDataHash
Parameters:
-
relationshipDataHash
Object
Returns:
_normalizeResourceHelper
-
resourceHash
Parameters:
-
resourceHash
Object
Returns:
_normalizeResponse
-
store
-
primaryModelClass
-
payload
-
id
-
requestType
-
isSingle
Parameters:
Returns:
JSON-API Document
applyTransforms
-
typeClass
-
data
Model
and a JSON object this method will
iterate through each attribute of the Model
and invoke the
Transform#deserialize
method on the matching property of the
JSON object. This method is typically called after the
serializer's normalize
method.
Parameters:
-
typeClass
Model -
data
ObjectThe data to transform
Returns:
extractAttributes
-
modelClass
-
resourceHash
Parameters:
-
modelClass
Object -
resourceHash
Object
Returns:
extractErrors
-
store
-
typeClass
-
payload
-
id
extractErrors
is used to extract model errors when a call
to 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 https://jsonapi.org/format/#errors specification:
`
js
{
"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:
`
javascript
{
"errors": [
{
"detail": "Some generic non property error message",
"source": {
"pointer": "data"
}
}
]
}
`
When turn into a Errors
object, you can read these errors
through the property base
:
`
handlebars
{{#each @model.errors.base as |error|}}
`
Example of alternative implementation, overriding the default
behavior to deal with a different format of errors:
`
app/serializers/post.js
import JSONSerializer from '@ember-data/serializer/json';
export default class PostSerializer extends JSONSerializer {
extractErrors(store, typeClass, payload, id) {
if (payload && typeof payload === 'object' && payload._problems) {
payload = payload._problems;
this.normalizeErrors(typeClass, payload);
}
return payload;
}
}
`
Returns:
extractId
-
modelClass
-
resourceHash
Parameters:
-
modelClass
Object -
resourceHash
Object
Returns:
extractMeta
-
store
-
modelClass
-
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
`
app/serializers/post.js
import JSONSerializer from '@ember-data/serializer/json';
export default class PostSerializer extends JSONSerializer {
extractMeta(store, typeClass, payload) {
if (payload && payload.hasOwnProperty('_pagination')) {
let meta = payload._pagination;
delete payload._pagination;
return meta;
}
}
}
`
extractPolymorphicRelationship
-
relationshipModelName
-
relationshipHash
-
relationshipOptions
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
Parameters:
-
relationshipModelName
Object -
relationshipHash
Object -
relationshipOptions
Object
Returns:
extractRelationship
-
relationshipHash
Returns a relationship formatted as a JSON-API "relationship object".
http://jsonapi.org/format/#document-resource-object-relationships
Parameters:
-
relationshipHash
Object
Returns:
extractRelationships
-
modelClass
-
resourceHash
Returns the resource's relationships formatted as a JSON-API "relationships object".
http://jsonapi.org/format/#document-resource-object-relationships
Parameters:
-
modelClass
Object -
resourceHash
Object
Returns:
keyForAttribute
-
key
-
method
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
import JSONAPISerializer from '@ember-data/serializer/json-api';
import { dasherize } from '<app-name>/utils/string-utils';
export default class ApplicationSerializer extends JSONAPISerializer {
keyForAttribute(attr, method) {
return dasherize(attr).toUpperCase();
}
}
Parameters:
-
key
String -
method
String
Returns:
normalized key
keyForLink
-
key
-
kind
keyForLink
can be used to define a custom key when deserializing link
properties.
Parameters:
-
key
String -
kind
StringbelongsTo
orhasMany
Returns:
keyForRelationship
-
key
-
typeClass
-
method
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
import JSONAPISerializer from '@ember-data/serializer/json-api';
import { underscore } from '<app-name>/utils/string-utils';
export default class ApplicationSerializer extends JSONAPISerializer {
keyForRelationship(key, relationship, method) {
return underscore(key);
}
}
Parameters:
-
key
String -
typeClass
String -
method
String
Returns:
normalized key
modelNameFromPayloadKey
-
key
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
.
Parameters:
-
key
String
Returns:
the model's modelName
normalize
-
typeClass
-
hash
`
app/serializers/application.js
import JSONSerializer from '@ember-data/serializer/json';
import { underscore } from '`
Parameters:
-
typeClass
Model -
hash
Object
Returns:
normalizeArrayResponse
-
store
-
primaryModelClass
-
payload
-
id
-
requestType
Parameters:
Returns:
normalizeCreateRecordResponse
-
store
-
primaryModelClass
-
payload
-
id
-
requestType
createRecord
Parameters:
Returns:
normalizeDeleteRecordResponse
-
store
-
primaryModelClass
-
payload
-
id
-
requestType
deleteRecord
Parameters:
Returns:
normalizeFindAllResponse
-
store
-
primaryModelClass
-
payload
-
id
-
requestType
findAll
Parameters:
Returns:
normalizeFindBelongsToResponse
-
store
-
primaryModelClass
-
payload
-
id
-
requestType
findBelongsTo
Parameters:
Returns:
normalizeFindHasManyResponse
-
store
-
primaryModelClass
-
payload
-
id
-
requestType
findHasMany
Parameters:
Returns:
normalizeFindManyResponse
-
store
-
primaryModelClass
-
payload
-
id
-
requestType
findMany
Parameters:
Returns:
normalizeFindRecordResponse
-
store
-
primaryModelClass
-
payload
-
id
-
requestType
findRecord
Parameters:
Returns:
normalizeQueryRecordResponse
-
store
-
primaryModelClass
-
payload
-
id
-
requestType
queryRecord
Parameters:
Returns:
normalizeQueryResponse
-
store
-
primaryModelClass
-
payload
-
id
-
requestType
query
Parameters:
Returns:
normalizeRelationships
()
private
normalizeResponse
-
store
-
primaryModelClass
-
payload
-
id
-
requestType
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 super.normalizeResponse(store, primaryModelClass, payload, id, requestType)
with your
pre-processed data.
Here's an example of using normalizeResponse
manually:
`
javascript
socket.on('message', function(message) {
let data = message.data;
let modelClass = store.modelFor(data.modelName);
let serializer = store.serializerFor(data.modelName);
let normalized = serializer.normalizeSingleResponse(store, modelClass, data, data.id);
store.push(normalized);
});
`
Parameters:
Returns:
normalizeSaveResponse
-
store
-
primaryModelClass
-
payload
-
id
-
requestType
Parameters:
Returns:
normalizeSingleResponse
-
store
-
primaryModelClass
-
payload
-
id
-
requestType
Parameters:
Returns:
normalizeUpdateRecordResponse
-
store
-
primaryModelClass
-
payload
-
id
-
requestType
updateRecord
Parameters:
Returns:
normalizeUsingDeclaredMapping
()
private
payloadKeyFromModelName
-
modelName
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
.
Parameters:
-
modelName
String
Returns:
pushPayload
-
store
-
payload
Normalize some data and push it into the store.
Parameters:
-
store
Store -
payload
Object
serialize
-
snapshot
-
options
Called when a record is saved in order to convert the record into JSON.
For example, consider this model:
import Model, { attr, belongsTo } from '@ember-data/model';
export default class CommentModel extends Model {
@attr title;
@attr body;
@belongsTo('user', { async: false, inverse: null })
author;
}
The default serialization would create a JSON-API resource object like:
{
"data": {
"type": "comments",
"attributes": {
"title": "Rails is unagi",
"body": "Rails? Omakase? O_O",
},
"relationships": {
"author": {
"data": {
"id": "12",
"type": "users"
}
}
}
}
}
By default, attributes are passed through as-is, unless
you specified an attribute type (attr('date')
). If
you specify a transform, the JavaScript value will be
serialized when inserted into the attributes hash.
Belongs-to relationships are converted into JSON-API resource identifier objects.
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 JSONAPIAdapter passes in includeId: true
when serializing a record
for createRecord
or updateRecord
.
Customization
Your server may expect data in a different format than the built-in serialization format.
In that case, you can implement serialize
yourself and
return data formatted to match your API's expectations, or override
the invoked adapter method and do the serialization in the adapter directly
by using the provided snapshot.
If your API's format differs greatly from the JSON:API spec, you should consider authoring your own adapter and serializer instead of extending this class.
import JSONAPISerializer from '@ember-data/serializer/json-api';
export default class PostSerializer extends JSONAPISerializer {
serialize(snapshot, options) {
let 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.
import JSONAPISerializer from '@ember-data/serializer/json-api';
import { underscore, singularize } from '<app-name>/utils/string-utils';
export default class ApplicationSerializer extends JSONAPISerializer {
serialize(snapshot, options) {
let json = {};
snapshot.eachAttribute((name) => {
json[serverAttributeName(name)] = snapshot.attr(name);
});
snapshot.eachRelationship((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 underscore(attribute).toUpperCase();
}
function serverHasManyName(name) {
return serverAttributeName(singularize(name)) + '_IDS';
}
This serializer will generate JSON that looks like this:
{
"TITLE": "Rails is omakase",
"BODY": "Yep. Omakase.",
"COMMENT_IDS": [ "1", "2", "3" ]
}
Tweaking the Default Formatting
If you just want to do some small tweaks on the default JSON:API formatted response,
you can call super.serialize
first and make the tweaks
on the returned object.
import JSONAPISerializer from '@ember-data/serializer/json-api';
export default class PostSerializer extends JSONAPISerializer {
serialize(snapshot, options) {
let json = super.serialize(...arguments);
json.data.attributes.subject = json.data.attributes.title;
delete json.data.attributes.title;
return json;
}
}
Parameters:
-
snapshot
Snapshot -
options
Object
Returns:
json
serializeAttribute
-
snapshot
-
json
-
key
-
attribute
serializeAttribute
can be used to customize how 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:
`
app/serializers/application.js
import JSONSerializer from '@ember-data/serializer/json';
export default class ApplicationSerializer extends JSONSerializer {
serializeAttribute(snapshot, json, key, attributes) {
json.attributes = json.attributes || {};
super.serializeAttribute(snapshot, json.attributes, key, attributes);
}
}
`
Parameters:
-
snapshot
Snapshot -
json
Object -
key
String -
attribute
Object
serializeBelongsTo
-
snapshot
-
json
-
relationship
serializeBelongsTo
can be used to customize how belongsTo
properties are serialized.
Example
`
app/serializers/post.js
import JSONSerializer from '@ember-data/serializer/json';
export default class PostSerializer extends JSONSerializer {
serializeBelongsTo(snapshot, json, relationship) {
let key = relationship.name;
let belongsTo = snapshot.belongsTo(key);
key = this.keyForRelationship ? this.keyForRelationship(key, "belongsTo", "serialize") : key;
json[key] = !belongsTo ? null : belongsTo.record.toJSON();
}
}
`
Parameters:
-
snapshot
Snapshot -
json
Object -
relationship
Object
serializeHasMany
-
snapshot
-
json
-
relationship
serializeHasMany
can be used to customize how hasMany
properties are serialized.
Example
`
app/serializers/post.js
import JSONSerializer from '@ember-data/serializer/json';
export default class PostSerializer extends JSONSerializer {
serializeHasMany(snapshot, json, relationship) {
let key = relationship.name;
if (key === 'comments') {
return;
} else {
super.serializeHasMany(...arguments);
}
}
}
`
Parameters:
-
snapshot
Snapshot -
json
Object -
relationship
Object
serializeIntoHash
-
hash
-
typeClass
-
snapshot
-
options
`
app/serializers/application.js
import RESTSerializer from '@ember-data/serializer/rest';
import { underscoren} from '`
serializePolymorphicType
-
snapshot
-
json
-
relationship
{ polymorphic: true }
is pass as the second argument to the
belongsTo
function.
Example
`
app/serializers/comment.js
import JSONSerializer from '@ember-data/serializer/json';
export default class CommentSerializer extends JSONSerializer {
serializePolymorphicType(snapshot, json, relationship) {
let key = relationship.name;
let belongsTo = snapshot.belongsTo(key);
key = this.keyForAttribute ? this.keyForAttribute(key, 'serialize') : key;
if (!belongsTo) {
json[key + '_type'] = null;
} else {
json[key + '_type'] = belongsTo.modelName;
}
}
}
`
Parameters:
-
snapshot
Snapshot -
json
Object -
relationship
Object
shouldSerializeHasMany
-
snapshot
-
key
-
relationship
attrs
object.
Parameters:
-
snapshot
Snapshot -
key
String -
relationship
RelationshipSchema
Returns:
Properties
attrs
Object
public
attrs
object can be used to declare a simple mapping between
property names on 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
`
app/models/person.js
import Model, { attr } from '@ember-data/model';
export default class PersonModel extends Model {
@attr('string') firstName;
@attr('string') lastName;
@attr('string') occupation;
@attr('boolean') admin;
}
`
`
app/serializers/person.js
import JSONSerializer from '@ember-data/serializer/json';
export default class PersonSerializer extends JSONSerializer {
attrs = {
admin: 'is_admin',
occupation: { key: 'career' }
}
}
`
You can also remove attributes and relationships by setting the serialize
key to false
in your mapping object.
Example
`
app/serializers/person.js
import JSONSerializer from '@ember-data/serializer/json';
export default class PostSerializer extends JSONSerializer {
attrs = {
admin: { serialize: false },
occupation: { key: 'career' }
}
}
`
When serialized:
`
javascript
{
"firstName": "Harry",
"lastName": "Houdini",
"career": "magician"
}
`
Note that the admin
is now not included in the payload.
Setting serialize
to true
enforces serialization for hasMany
relationships even if it's neither a many-to-many nor many-to-none
relationship.
primaryKey
String
public
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
`
app/serializers/application.js
import JSONSerializer from '@ember-data/serializer/json';
export default class ApplicationSerializer extends JSONSerializer {
primaryKey = '_id'
}
`
Default: 'id'
store
Store
public
The store
property is the application's store
that contains
all records. It can be used to look up serializers for other model
types that may be nested inside the payload response.
Example:
Serializer.extend({
extractRelationship(relationshipModelName, relationshipHash) {
let modelClass = this.store.modelFor(relationshipModelName);
let relationshipSerializer = this.store.serializerFor(relationshipModelName);
return relationshipSerializer.normalize(modelClass, relationshipHash);
}
});