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

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