# Unlike other backends, require YAML if it's not already loaded require 'yaml' unless defined?(YAML) module OEmbed module Formatter module JSON module Backends # Use the YAML library, part of the standard library, to parse JSON values that has been converted to YAML. module Yaml extend self # Parses a JSON string or IO and converts it into an object. def decode(json) if json.respond_to?(:read) json = json.read end YAML.load(convert_json_to_yaml(json)) rescue ArgumentError raise parse_error, "Invalid JSON string" end def decode_fail_msg "The version of the YAML library you have installed isn't parsing JSON like ruby-oembed expected." end def parse_error ::StandardError end protected # Ensure that ":" and "," are always followed by a space def convert_json_to_yaml(json) #:nodoc: require 'strscan' unless defined? ::StringScanner scanner, quoting, marks, pos = ::StringScanner.new(json), false, [], nil scanner.scan_until(/\{/) while scanner.scan_until(/(\\['"]|['":,\\]|\\.)/) case char = scanner[1] when '"', "'" if !quoting quoting = char pos = scanner.pos elsif quoting == char quoting = false end when ":","," marks << scanner.pos - 1 unless quoting when "\\" scanner.skip(/\\/) end end raise parse_error unless scanner.scan_until(/\}/) if marks.empty? raise parse_error 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 chunk = scanner.peek(right_pos[i] - scanner.pos + 1) chunk.gsub!(/\\([\\\/]|u[[:xdigit:]]{4})/) do ustr = $1 if ustr.index('u') == 0 [ustr[1..-1].to_i(16)].pack("U") elsif ustr == '\\' '\\\\' else ustr end end output << chunk end output = output * " " output.gsub!(/\\\//, '/') output end end end end end end end