Adapter Options adapter_opts

Adapter Options are passed to new Adapters and are specified in ActiveModelSerializers::SerializableResource::ADAPTER_OPTIONS

adapter

PR please :)

fields

• To restrict the fields returned, you should use fields option.

For example, if you have a serializer like this

class UserSerializer < ActiveModel::Serializer
  attributes :access_token, :first_name, :last_name
end

and in a specific controller, you want to return access_token only, fields will help you:

class AnonymousController < ApplicationController
  def create
    render json: User.create(activation_state: 'anonymous'), fields: [:access_token], status: 201
  end
end

Note that this is only valid for the json and attributes adapter. For the json_api adapter, you would use

render json: @user, fields: { users: [:access_token] }

Where users is the JSONAPI type.

key_transform

render json: posts, each_serializer: PostSerializer, key_transform: :camel_lower

See Global Configurations options for more about setting key transform globally

meta

A meta member can be used to include non-standard meta-information. meta can be utilized in several levels in a response.

Top-level

To set top-level meta in a response, specify it in the render call.

render json: @post, meta: { total: 10 }

The key can be customized using meta_key option.

render json: @post, meta: { total: 10 }, meta_key: "custom_meta"

meta will only be included in your response if you are using an Adapter that supports root, e.g., JsonApi and Json adapters. The default adapter, Attributes does not have root.

Resource-level

To set resource-level meta in a response, define meta in a serializer with one of the following methods:

As a single, static string.

meta stuff: 'value'

As a block containing a Hash.

meta do
  {
    rating: 4,
    comments_count: object.comments.count
  }
end

links (JSON API Adapter)

If you wish to use Rails url helpers for link generation, e.g., link(:resources) { resources_url }, ensure your application sets Rails.application.routes.default_url_options.

Top-level

JsonApi supports a links object to be specified at top-level, that you can specify in the render:

  links_object = {
    href: "http://example.com/api/posts",
    meta: {
      count: 10
    }
  }
  render json: @posts, links: links_object

That's the result:

{
  "data": [
    {
      "type": "posts",
      "id": "1",
      "attributes": {
        "title": "JSON API is awesome!",
        "body": "You should be using JSON API",
        "created": "2015-05-22T14:56:29.000Z",
        "updated": "2015-05-22T14:56:28.000Z"
      }
    }
  ],
  "links": {
    "href": "http://example.com/api/posts",
    "meta": {
      "count": 10
    }
  }
}

This feature is specific to JsonApi, so you have to use the use the JsonApi Adapter

Resource-level

In your serializer, define each link in one of the following methods:

As a static string

link :link_name, 'https://example.com/resource'

As a block to be evaluated. When using Rails, URL helpers are available. Ensure your application sets Rails.application.routes.default_url_options.

link :link_name_ do
  "https://example.com/resource/#{object.id}"
end

link(:link_name) { "https://example.com/resource/#{object.id}" }

link(:link_name) { resource_url(object) }

link(:link_name) { url_for(controller: 'controller_name', action: 'index', only_path: false) }