module CGI::Util

Constants

RFC822_DAYS

Abbreviated day-of-week names specified by RFC 822

RFC822_MONTHS

Abbreviated month names specified by RFC 822

TABLE_FOR_ESCAPE_HTML__

The set of special characters and their escaped values

Public Instance Methods

escape(string) Show source
# File lib/cgi/util.rb, line 12
def escape(string)
  encoding = string.encoding
  string.b.gsub(/([^ a-zA-Z0-9_.\-~]+)/) do |m|
    '%' + m.unpack('H2' * m.bytesize).join('%').upcase
  end.tr(' ', '+').force_encoding(encoding)
end

URL-encode a string.

url_encoded_string = CGI.escape("'Stop!' said Fred")
   # => "%27Stop%21%27+said+Fred"
escapeElement(string, *elements) Show source
# File lib/cgi/util.rb, line 140
def escapeElement(string, *elements)
  elements = elements[0] if elements[0].kind_of?(Array)
  unless elements.empty?
    string.gsub(/<\/?(?:#{elements.join("|")})(?!\w)(?:.|\n)*?>/i) do
      CGI.escapeHTML($&)
    end
  else
    string
  end
end

Escape only the tags of certain HTML elements in string.

Takes an element or elements or array of elements. Each element is specified by the name of the element, without angle brackets. This matches both the start and the end tag of that element. The attribute list of the open tag will also be escaped (for instance, the double-quotes surrounding attribute values).

print CGI.escapeElement('<BR><A HREF="url"></A>', "A", "IMG")
  # "<BR>&lt;A HREF=&quot;url&quot;&gt;&lt;/A&gt"

print CGI.escapeElement('<BR><A HREF="url"></A>', ["A", "IMG"])
  # "<BR>&lt;A HREF=&quot;url&quot;&gt;&lt;/A&gt"
Also aliased as: escape_element
escapeHTML(string) Show source
# File lib/cgi/util.rb, line 41
def escapeHTML(string)
  enc = string.encoding
  unless enc.ascii_compatible?
    if enc.dummy?
      origenc = enc
      enc = Encoding::Converter.asciicompat_encoding(enc)
      string = enc ? string.encode(enc) : string.b
    end
    table = Hash[TABLE_FOR_ESCAPE_HTML__.map {|pair|pair.map {|s|s.encode(enc)}}]
    string = string.gsub(/#{"['&\"<>]".encode(enc)}/, table)
    string.encode!(origenc) if origenc
    return string
  end
  string.gsub(/['&\"<>]/, TABLE_FOR_ESCAPE_HTML__)
end

Escape special characters in HTML, namely '&"<>

CGI.escapeHTML('Usage: foo "bar" <baz>')
   # => "Usage: foo &quot;bar&quot; &lt;baz&gt;"
Also aliased as: escape_html, h
escape_element(string, *elements)
Alias for: escapeElement
escape_html(string)

Synonym for CGI.escapeHTML(str)

Alias for: escapeHTML
h(string)
Alias for: escapeHTML
pretty(string, shift = " ") Show source
# File lib/cgi/util.rb, line 211
def pretty(string, shift = "  ")
  lines = string.gsub(/(?!\A)<.*?>/m, "\n\\0").gsub(/<.*?>(?!\n)/m, "\\0\n")
  end_pos = 0
  while end_pos = lines.index(/^<\/(\w+)/, end_pos)
    element = $1.dup
    start_pos = lines.rindex(/^\s*<#{element}/i, end_pos)
    lines[start_pos ... end_pos] = "__" + lines[start_pos ... end_pos].gsub(/\n(?!\z)/, "\n" + shift) + "__"
  end
  lines.gsub(/^((?:#{Regexp::quote(shift)})*)__(?=<\/?\w)/, '\1')
end

Prettify (indent) an HTML string.

string is the HTML string to indent. shift is the indentation unit to use; it defaults to two spaces.

print CGI.pretty("<HTML><BODY></BODY></HTML>")
  # <HTML>
  #   <BODY>
  #   </BODY>
  # </HTML>

print CGI.pretty("<HTML><BODY></BODY></HTML>", "\t")
  # <HTML>
  #         <BODY>
  #         </BODY>
  # </HTML>
rfc1123_date(time) Show source
# File lib/cgi/util.rb, line 187
def rfc1123_date(time)
  t = time.clone.gmtime
  return format("%s, %.2d %s %.4d %.2d:%.2d:%.2d GMT",
                RFC822_DAYS[t.wday], t.day, RFC822_MONTHS[t.month-1], t.year,
                t.hour, t.min, t.sec)
end

Format a Time object as a String using the format specified by RFC 1123.

CGI.rfc1123_date(Time.now)
  # Sat, 01 Jan 2000 00:00:00 GMT
unescape(string,encoding=@@accept_charset) Show source
# File lib/cgi/util.rb, line 22
def unescape(string,encoding=@@accept_charset)
  str=string.tr('+', ' ').b.gsub(/((?:%[0-9a-fA-F]{2})+)/) do |m|
    [m.delete('%')].pack('H*')
  end.force_encoding(encoding)
  str.valid_encoding? ? str : str.force_encoding(string.encoding)
end

URL-decode a string with encoding(optional).

string = CGI.unescape("%27Stop%21%27+said+Fred")
   # => "'Stop!' said Fred"
unescapeElement(string, *elements) Show source
# File lib/cgi/util.rb, line 160
def unescapeElement(string, *elements)
  elements = elements[0] if elements[0].kind_of?(Array)
  unless elements.empty?
    string.gsub(/&lt;\/?(?:#{elements.join("|")})(?!\w)(?:.|\n)*?&gt;/i) do
      unescapeHTML($&)
    end
  else
    string
  end
end

Undo escaping such as that done by CGI.escapeElement()

print CGI.unescapeElement(
        CGI.escapeHTML('<BR><A HREF="url"></A>'), "A", "IMG")
  # "&lt;BR&gt;<A HREF="url"></A>"

print CGI.unescapeElement(
        CGI.escapeHTML('<BR><A HREF="url"></A>'), ["A", "IMG"])
  # "&lt;BR&gt;<A HREF="url"></A>"
Also aliased as: unescape_element
unescapeHTML(string) Show source
# File lib/cgi/util.rb, line 65
def unescapeHTML(string)
  enc = string.encoding
  unless enc.ascii_compatible?
    if enc.dummy?
      origenc = enc
      enc = Encoding::Converter.asciicompat_encoding(enc)
      string = enc ? string.encode(enc) : string.b
    end
    string = string.gsub(Regexp.new('&(apos|amp|quot|gt|lt|#[0-9]+|#x[0-9A-Fa-f]+);'.encode(enc))) do
      case $1.encode(Encoding::US_ASCII)
      when 'apos'                then "'".encode(enc)
      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
    string.encode!(origenc) if origenc
    return string
  end
  return string unless string.include? '&'
  charlimit = case enc
              when Encoding::UTF_8; 0x10ffff
              when Encoding::ISO_8859_1; 256
              else 128
              end
  string.gsub(/&(apos|amp|quot|gt|lt|\#[0-9]+|\#[xX][0-9A-Fa-f]+);/) do
    match = $1.dup
    case match
    when 'apos'                then "'"
    when 'amp'                 then '&'
    when 'quot'                then '"'
    when 'gt'                  then '>'
    when 'lt'                  then '<'
    when /\A#0*(\d+)\z/
      n = $1.to_i
      if n < charlimit
        n.chr(enc)
      else
        "&##{$1};"
      end
    when /\A#x([0-9a-f]+)\z/i
      n = $1.hex
      if n < charlimit
        n.chr(enc)
      else
        "&#x#{$1};"
      end
    else
      "&#{match};"
    end
  end
end

Unescape a string that has been HTML-escaped

CGI.unescapeHTML("Usage: foo &quot;bar&quot; &lt;baz&gt;")
   # => "Usage: foo \"bar\" <baz>"
Also aliased as: unescape_html
unescape_element(string, *elements)
Alias for: unescapeElement
unescape_html(string)

Synonym for CGI.unescapeHTML(str)

Alias for: unescapeHTML

Ruby Core © 1993–2020 Yukihiro Matsumoto
Licensed under the Ruby License.
Ruby Standard Library © contributors
Licensed under their own licenses.