Method: CGI.unescapeHTML

Defined in:
lib/cgi/util.rb

.unescapeHTML(string) ⇒ Object

Unescape a string that has been HTML-escaped

CGI::unescapeHTML("Usage: foo "bar" <baz>")
   # => "Usage: foo \"bar\" <baz>"



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# File 'lib/cgi/util.rb', line 41

def CGI::unescapeHTML(string)
  enc = string.encoding
  if [Encoding::UTF_16BE, Encoding::UTF_16LE, Encoding::UTF_32BE, Encoding::UTF_32LE].include?(enc)
    return string.gsub(Regexp.new('&(amp|quot|gt|lt|#[0-9]+|#x[0-9A-Fa-f]+);'.encode(enc))) do
      case $1.encode("US-ASCII")
      when 'amp'                 then '&'.encode(enc)
      when 'quot'                then '"'.encode(enc)
      when 'gt'                  then '>'.encode(enc)
      when 'lt'                  then '<'.encode(enc)
      when /\A#0*(\d+)\z/        then $1.to_i.chr(enc)
      when /\A#x([0-9a-f]+)\z/i  then $1.hex.chr(enc)
      end
    end
  end
  asciicompat = Encoding.compatible?(string, "a")
  string.gsub(/&(amp|quot|gt|lt|\#[0-9]+|\#x[0-9A-Fa-f]+);/) do
    match = $1.dup
    case match
    when 'amp'                 then '&'
    when 'quot'                then '"'
    when 'gt'                  then '>'
    when 'lt'                  then '<'
    when /\A#0*(\d+)\z/
      n = $1.to_i
      if enc == Encoding::UTF_8 or
        enc == Encoding::ISO_8859_1 && n < 256 or
        asciicompat && n < 128
        n.chr(enc)
      else
        "&##{$1};"
      end
    when /\A#x([0-9a-f]+)\z/i
      n = $1.hex
      if enc == Encoding::UTF_8 or
        enc == Encoding::ISO_8859_1 && n < 256 or
        asciicompat && n < 128
        n.chr(enc)
      else
        "&#x#{$1};"
      end
    else
      "&#{match};"
    end
  end
end