# File lib/amrita/format.rb, line 21
    def sanitize_text(text)
      s = text.dup
      s.gsub!(AMP_WITHOUT_REFRENCE, '&')
      s.gsub!("<", '<')
      s.gsub!(">", '>')
      s
    end
| sanitize_attribute_value(text) | 
# File lib/amrita/format.rb, line 30
    def sanitize_attribute_value(text)
      s = text.dup
      s.gsub!(AMP_WITHOUT_REFRENCE, '&')
      s.gsub!("<", '<')
      s.gsub!(">", '>')
      s.gsub!('"', '"')
      s.gsub!("'", ''')
      s
    end
| sanitize_url(text, allowd_scheme = DefaultAllowedScheme) | 
sanitize_url accepts only
these characters
    --- http://www.ietf.org/rfc/rfc2396.txt ---
    uric = reserved | unreserved | escaped
    reserved = ";" | "/" | "?" | ":" | "@" | "&" | "=" | "+" | "$" | ","
    unreserved = alphanum | mark
    mark = "-" | "_" | "." | "!" | "~" | "*" | "'" | "(" | ")"
    escaped = "%" hex hex
sanitize_url accepts only
schems specified by allowd_scheme
The default is http: https: ftp: mailt:
 
# File lib/amrita/format.rb, line 62
    def  sanitize_url(text, allowd_scheme = DefaultAllowedScheme)
      # return nil if text has characters not allowd for URL
      return nil if text =~ UrlInvalidChar
      # return '' if text has an unknown scheme
      # --- http://www.ietf.org/rfc/rfc2396.txt ---
      # scheme = alpha *( alpha | digit | "+" | "-" | "." )
      if text =~ |^([A-Za-z][A-Za-z0-9+\-.]*):| 
        return nil unless allowd_scheme[$1]
      end
  
      # escape HTML
      # special = "&" | "<" | ">" | '"' | "'"
      # But I checked  "<" | ">" | '"' before.
      s = text.dup
      #s.gsub!("&", '&')
      s.gsub!("'", ''')
      s
    end