require 'active_support/json' module ActiveModel module Serializers # == Active Model JSON Serializer module JSON extend ActiveSupport::Concern include ActiveModel::Serialization included do extend ActiveModel::Naming class_attribute :include_root_in_json self.include_root_in_json = false end # Returns a hash representing the model. Some configuration can be # passed through +options+. # # The option include_root_in_json controls the top-level behavior # of +as_json+. If +true+, +as_json+ will emit a single root node named # after the object's type. The default value for include_root_in_json # option is +false+. # # user = User.find(1) # user.as_json # # => { "id" => 1, "name" => "Konata Izumi", "age" => 16, # # "created_at" => "2006/08/01", "awesome" => true} # # ActiveRecord::Base.include_root_in_json = true # # user.as_json # # => { "user" => { "id" => 1, "name" => "Konata Izumi", "age" => 16, # # "created_at" => "2006/08/01", "awesome" => true } } # # This behavior can also be achieved by setting the :root option # to +true+ as in: # # user = User.find(1) # user.as_json(root: true) # # => { "user" => { "id" => 1, "name" => "Konata Izumi", "age" => 16, # # "created_at" => "2006/08/01", "awesome" => true } } # # Without any +options+, the returned Hash will include all the model's # attributes. # # user = User.find(1) # user.as_json # # => { "id" => 1, "name" => "Konata Izumi", "age" => 16, # # "created_at" => "2006/08/01", "awesome" => true} # # The :only and :except options can be used to limit # the attributes included, and work similar to the +attributes+ method. # # user.as_json(only: [:id, :name]) # # => { "id" => 1, "name" => "Konata Izumi" } # # user.as_json(except: [:id, :created_at, :age]) # # => { "name" => "Konata Izumi", "awesome" => true } # # To include the result of some method calls on the model use :methods: # # user.as_json(methods: :permalink) # # => { "id" => 1, "name" => "Konata Izumi", "age" => 16, # # "created_at" => "2006/08/01", "awesome" => true, # # "permalink" => "1-konata-izumi" } # # To include associations use :include: # # user.as_json(include: :posts) # # => { "id" => 1, "name" => "Konata Izumi", "age" => 16, # # "created_at" => "2006/08/01", "awesome" => true, # # "posts" => [ { "id" => 1, "author_id" => 1, "title" => "Welcome to the weblog" }, # # { "id" => 2, "author_id" => 1, "title" => "So I was thinking" } ] } # # Second level and higher order associations work as well: # # user.as_json(include: { posts: { # include: { comments: { # only: :body } }, # only: :title } }) # # => { "id" => 1, "name" => "Konata Izumi", "age" => 16, # # "created_at" => "2006/08/01", "awesome" => true, # # "posts" => [ { "comments" => [ { "body" => "1st post!" }, { "body" => "Second!" } ], # # "title" => "Welcome to the weblog" }, # # { "comments" => [ { "body" => "Don't think too hard" } ], # # "title" => "So I was thinking" } ] } def as_json(options = nil) root = if options && options.key?(:root) options[:root] else include_root_in_json end if root root = self.class.model_name.element if root == true { root => serializable_hash(options) } else serializable_hash(options) end end # Sets the model +attributes+ from a JSON string. Returns +self+. # # class Person # include ActiveModel::Serializers::JSON # # attr_accessor :name, :age, :awesome # # def attributes=(hash) # hash.each do |key, value| # send("#{key}=", value) # end # end # # def attributes # instance_values # end # end # # json = { name: 'bob', age: 22, awesome:true }.to_json # person = Person.new # person.from_json(json) # => # # person.name # => "bob" # person.age # => 22 # person.awesome # => true # # The default value for +include_root+ is +false+. You can change it to # +true+ if the given JSON string includes a single root node. # # json = { person: { name: 'bob', age: 22, awesome:true } }.to_json # person = Person.new # person.from_json(json) # => # # person.name # => "bob" # person.age # => 22 # person.awesome # => true def from_json(json, include_root=include_root_in_json) hash = ActiveSupport::JSON.decode(json) hash = hash.values.first if include_root self.attributes = hash self end end end end