Ember Data ActiveModel Adapter

ember install active-model-adapter

• Ember.js v3.24 or above
• Ember CLI v3.24 or above
• Node.js v12 or above

You should make an ApplicationAdapter if you don't already have one:

// app/adapters/application.js
import ActiveModelAdapter from 'active-model-adapter';

export default class ApplicationAdapter extends ActiveModelAdapter {}

If you need to subclass the ActiveModelSerializer, you can import it into your serializer:

// app/serializers/post.js

import { ActiveModelSerializer } from 'active-model-adapter';

export default class PostSerializer extends ActiveModelSerializer {}

The ActiveModelAdapter is a subclass of the RESTAdapter designed to integrate with a JSON API that uses an underscored naming convention instead of camelCasing.

It has been designed to work out of the box with the active_model_serializers Ruby gem. This Adapter expects specific settings using ActiveModel::Serializers, embed :ids, embed_in_root: true which sideloads the records.

The ActiveModelAdapter expects the JSON returned from your server to follow the REST adapter conventions substituting underscored keys for camelcased ones. Unlike the DS.RESTAdapter, async relationship keys must be the singular form of the relationship name, followed by "_id" for DS.belongsTo relationships, or "_ids" for DS.hasMany relationships.

Since ActiveModelAdapter 2.1.0 however, you don't need the "_id" or "_ids" suffix on keys for relationships.

Attribute names in your JSON payload should be the underscored versions of the attributes in your Ember.js models. For example, if you have a Person model:

// app/models/famous-person.js

export default class FamousPerson extends Model {
  @attr() firstName;
  @attr() lastName;
  @attr() occupation;
}

The JSON returned should look like this:

{
  "famous_person": {
    "id": 1,
    "first_name": "Barack",
    "last_name": "Obama",
    "occupation": "President"
  }
}

Let's imagine that Occupation and Person are just another model:

// app/models/person.js

export default class Person extends Model {
  @attr() firstName;
  @attr() lastName;
  @belongsTo('occupation') occupation;
}

// app/models/occupation.js
export default class Occupation extends Model {
  @attr() name;
  @attr('number') salary;
  @hasMany('person') people;
}

The JSON needed to avoid extra server calls, should look like this:

{
  "people": [
    {
      "id": 1,
      "first_name": "Barack",
      "last_name": "Obama",
      "occupation_id": 1
    }
  ],
  "occupations": [
    {
      "id": 1,
      "name": "President",
      "salary": 100000,
      "person_ids": [1]
    }
  ]
}

If your model has polymorphic relationships, the ActiveModelAdapter supports two forms in your response.

When using ActiveModelSerializers in Rails, you can opt into this payload using the polymorphic: true option when calling has_many or belongs_to.

class BookSerializer
  attributes :id, :name
  belongs_to :person, polymorphic: true
end

The first, and preferred format, is to use the name of the relationship as the key and an object with the type and foreign key as the value.

For example, given the following model definitions:

// app/models/book.js
export default class Book extends Model {
  @attr() name;
  @belongsTo('person', { polymorphic: true }) author;
}

// app/models/author.js
export default class Author extends Model {
  @attr() name;
  @hasMany('book') books;
}

The object would look like:

{
  "type": "person",
  "id": 1
}

and the full payload would look like this:

{
  "book": {
    "id": "1",
    "name": "Yes, Please",
    "author": { // these are the lines
      "id": 1, // that define the
      "type": "person" // polymorphic relationship
    }
  },
  "people": [{
    "id": 1,
    "name": "Amy Poehler"
  }]
}

The second format allows you to specify using two keys in the model's payload following the format of relationship_name_id and relationship_name_type. This format does not work with hasMany relationships. This format may also be removed for Ember Data 3.0; it is currently only supported for legacy reasons.

Using the above model definitions, the single model response would look like this:

{
  "book": {
    "id": "1",
    "name": "Yes, Please",
    "author_id": 1,         // these two lines
    "author_type": "person" // tell Ember Data what the polymorphic
                            // relationship is.
  }
}

The full response would be look like this:

{
  "book": {
    "id": "1",
    "name": "Yes, Please",
    "author_id": 1,         // these two lines
    "author_type": "person" // tell Ember Data what the polymorphic
                            // relationship is.
  },
  "people": [{
    "id": 1,
    "name": "Amy Poehler"
  }]
}

• git clone this repository
• yarn install

• ember test
• ember test --server

• ember build

For more information on using ember-cli, visit http://www.ember-cli.com/.