Oj::Serializer

This guide covers using Typelizer with Oj::Serializer.

Setup

class ApplicationSerializer < Oj::Serializer
  include Typelizer::DSL
end

Attributes and Associations

Define attributes and associations as usual:

class PostSerializer < ApplicationSerializer
  attributes :id, :title, :body

  has_one :author, serializer: AuthorSerializer
  has_many :comments, serializer: CommentSerializer
  belongs_to :created_by, serializer: UserSerializer
end

Typelizer infers types from the model. Use typelize_from when the model name can't be inferred:

class AuthorSerializer < ApplicationSerializer
  typelize_from User
  attributes :id, :name
end

Key Transformation

Oj's transform_keys is respected:

class PostSerializer < ApplicationSerializer
  transform_keys :camel_case

  attributes :id, :title, :created_at
end

Flat Associations

Oj::Serializer's flat_one inlines an association's attributes into the parent type alongside the nested reference:

class UserSerializer < ApplicationSerializer
  attributes :id, :name

  flat_one :invitor, serializer: UserSerializer
end

The invitor's attributes (username, active, name, etc.) are merged directly into the parent type. The invitor property itself is also kept in the output.

Conditional and Nullable Attributes

Oj::Serializer supports optional and nullable flags directly:

class PostSerializer < ApplicationSerializer
  attributes :id, :title
  attribute :draft, optional: true
  attribute :deleted_at, nullable: true
end

See Manual Typing for full details on the typelize method.