vendor/rails/activesupport/lib/active_support/json/encoding.rb

   1 require 'active_support/json/variable'
   2 require 'active_support/json/encoders/object' # Require explicitly for rdoc.
   3 Dir["#{File.dirname(__FILE__)}/encoders/**/*.rb"].each do |file|
   4   basename = File.basename(file, '.rb')
   5   unless basename == 'object'
   6     require "active_support/json/encoders/#{basename}"
   7   end
   8 end
   9
  10 module ActiveSupport
  11   module JSON
  12     class CircularReferenceError < StandardError
  13     end
  14
  15     class << self
  16       REFERENCE_STACK_VARIABLE = :json_reference_stack #:nodoc:
  17
  18       # Converts a Ruby object into a JSON string.
  19       def encode(value, options = {})
  20         raise_on_circular_reference(value) do
  21           value.send(:to_json, options)
  22         end
  23       end
  24
  25       protected
  26         def raise_on_circular_reference(value) #:nodoc:
  27           stack = Thread.current[REFERENCE_STACK_VARIABLE] ||= []
  28           raise CircularReferenceError, 'object references itself' if
  29             stack.include? value
  30           stack << value
  31           yield
  32         ensure
  33           stack.pop
  34         end
  35     end
  36   end
  37 end