Class EmbeddedRecordsMixin


Using Embedded Records

EmbeddedRecordsMixin supports serializing embedded records.

To set up embedded records, include the mixin when extending a serializer, then define and configure embedded (model) relationships.

Note that embedded records will serialize with the serializer for their model instead of the serializer in which they are defined.

Note also that this mixin does not work with JSONAPISerializer because the JSON:API specification does not describe how to format embedded resources.

Below is an example of a per-type serializer (post type).

import RESTSerializer, { EmbeddedRecordsMixin } from '@ember-data/serializer/rest';

export default class PostSerializer extends RESTSerializer.extend(EmbeddedRecordsMixin) {
  attrs = {
    author: { embedded: 'always' },
    comments: { serialize: 'ids' }

Note that this use of { embedded: 'always' } is unrelated to the { embedded: 'always' } that is defined as an option on attr as part of defining a model while working with the ActiveModelSerializer. Nevertheless, using { embedded: 'always' } as an option to attr is not a valid way to set up embedded records.

The attrs option for a resource { embedded: 'always' } is shorthand for:

  serialize: 'records',
  deserialize: 'records'

Configuring Attrs

A resource's attrs option may be set to use ids, records or false for the serialize and deserialize settings.

The attrs property can be set on the ApplicationSerializer or a per-type serializer.

In the case where embedded JSON is expected while extracting a payload (reading) the setting is deserialize: 'records', there is no need to use ids when extracting as that is the default behaviour without this mixin if you are using the vanilla EmbeddedRecordsMixin. Likewise, to embed JSON in the payload while serializing serialize: 'records' is the setting to use. There is an option of not embedding JSON in the serialized payload by using serialize: 'ids'. If you do not want the relationship sent at all, you can use serialize: false.

EmbeddedRecordsMixin defaults

If you do not overwrite attrs for a specific relationship, the EmbeddedRecordsMixin will behave in the following way:

BelongsTo: { serialize: 'id', deserialize: 'id' } HasMany: { serialize: false, deserialize: 'ids' }

Model Relationships

Embedded records must have a model defined to be extracted and serialized. Note that when defining any relationships on your model such as belongsTo and hasMany, you should not both specify async: true and also indicate through the serializer's attrs attribute that the related model should be embedded for deserialization. If a model is declared embedded for deserialization (embedded: 'always' or deserialize: 'records'), then do not use async: true.

To successfully extract and serialize embedded records the model relationships must be set up correctly. See the defining relationships section of the Defining Models guide page.

Records without an id property are not considered embedded records, model instances must have an id property to be used with Ember Data.

Example JSON payloads, Models and Serializers

When customizing a serializer it is important to grok what the customizations are. Please read the docs for the methods this mixin provides, in case you need to modify it to fit your specific needs.

For example, review the docs for each method of this mixin:




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