require 'yaml' require 'strscan' module ActiveSupport module JSON class ParseError < StandardError end class << self # Converts a JSON string into a Ruby object. def decode(json) YAML.load(convert_json_to_yaml(json)) rescue ArgumentError => e raise ParseError, "Invalid JSON string" end protected # matches YAML-formatted dates DATE_REGEX = /^(?:\d{4}-\d{2}-\d{2}|\d{4}-\d{1,2}-\d{1,2}[ \t]+\d{1,2}:\d{2}:\d{2}(\.[0-9]*)?(([ \t]*)Z|[-+]\d{2}?(:\d{2})?)?)$/ # Ensure that ":" and "," are always followed by a space def convert_json_to_yaml(json) #:nodoc: scanner, quoting, marks, pos, times = StringScanner.new(json), false, [], nil, [] while scanner.scan_until(/(\\['"]|['":,\\]|\\.)/) case char = scanner[1] when '"', "'" if !quoting quoting = char pos = scanner.pos elsif quoting == char if json[pos..scanner.pos-2] =~ DATE_REGEX # found a date, track the exact positions of the quotes so we can remove them later. # oh, and increment them for each current mark, each one is an extra padded space that bumps # the position in the final YAML output total_marks = marks.size times << pos+total_marks << scanner.pos+total_marks end quoting = false end when ":","," marks << scanner.pos - 1 unless quoting end end if marks.empty? json.gsub(/\\([\\\/]|u[[:xdigit:]]{4})/) do ustr = $1 if ustr.starts_with?('u') [ustr[1..-1].to_i(16)].pack("U") elsif ustr == '\\' '\\\\' else ustr end end else left_pos = [-1].push(*marks) right_pos = marks << scanner.pos + scanner.rest_size output = [] left_pos.each_with_index do |left, i| scanner.pos = left.succ output << scanner.peek(right_pos[i] - scanner.pos + 1).gsub(/\\([\\\/]|u[[:xdigit:]]{4})/) do ustr = $1 if ustr.starts_with?('u') [ustr[1..-1].to_i(16)].pack("U") elsif ustr == '\\' '\\\\' else ustr end end end output = output * " " times.each { |i| output[i-1] = ' ' } output.gsub!(/\\\//, '/') output end end end end end