require 'active_support/json'
module ActiveRecord #:nodoc:
module Serialization
def self.included(base)
base.cattr_accessor :include_root_in_json, :instance_writer => false
base.extend ClassMethods
end
# Returns a JSON string representing the model. Some configuration is
# available through +options+.
#
# The option ActiveRecord::Base.include_root_in_json controls the
# top-level behavior of to_json. In a new Rails application, it is set to
# true in initializers/new_rails_defaults.rb. When it is true,
# to_json will emit a single root node named after the object's type. For example:
#
# konata = User.find(1)
# ActiveRecord::Base.include_root_in_json = true
# konata.to_json
# # => { "user": {"id": 1, "name": "Konata Izumi", "age": 16,
# "created_at": "2006/08/01", "awesome": true} }
#
# ActiveRecord::Base.include_root_in_json = false
# konata.to_json
# # => {"id": 1, "name": "Konata Izumi", "age": 16,
# "created_at": "2006/08/01", "awesome": true}
#
# The remainder of the examples in this section assume include_root_in_json is set to
# false.
#
# Without any +options+, the returned JSON string will include all
# the model's attributes. For example:
#
# konata = User.find(1)
# konata.to_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. For example:
#
# konata.to_json(:only => [ :id, :name ])
# # => {"id": 1, "name": "Konata Izumi"}
#
# konata.to_json(:except => [ :id, :created_at, :age ])
# # => {"name": "Konata Izumi", "awesome": true}
#
# To include any methods on the model, use :methods.
#
# konata.to_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.
#
# konata.to_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"}]}
#
# 2nd level and higher order associations work as well:
#
# konata.to_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 to_json(options = {})
json = JsonSerializer.new(self, options).to_s
if include_root_in_json
"{#{self.class.json_class_name}:#{json}}"
else
json
end
end
# For compatibility with ActiveSupport::JSON.encode
alias rails_to_json to_json
def from_json(json)
self.attributes = ActiveSupport::JSON.decode(json)
self
end
class JsonSerializer < ActiveRecord::Serialization::Serializer #:nodoc:
def serialize
ActiveSupport::JSON.encode(serializable_record)
end
end
module ClassMethods
def json_class_name
@json_class_name ||= name.demodulize.underscore.inspect
end
end
end
end