File indexing completed on 2024-05-05 06:02:15

 <?php
 
 /**
  * Base class for all validating attribute definitions.
  *
  * This family of classes forms the core for not only HTML attribute validation,
  * but also any sort of string that needs to be validated or cleaned (which
  * means CSS properties and composite definitions are defined here too).
  * Besides defining (through code) what precisely makes the string valid,
  * subclasses are also responsible for cleaning the code if possible.
  */
 
 abstract class HTMLPurifier_AttrDef
 {
 
     /**
      * Tells us whether or not an HTML attribute is minimized.
      * Has no meaning in other contexts.
      * @type bool
      */
     public $minimized = false;
 
     /**
      * Tells us whether or not an HTML attribute is required.
      * Has no meaning in other contexts
      * @type bool
      */
     public $required = false;
 
     /**
      * Validates and cleans passed string according to a definition.
      *
      * @param string $string String to be validated and cleaned.
      * @param HTMLPurifier_Config $config Mandatory HTMLPurifier_Config object.
      * @param HTMLPurifier_Context $context Mandatory HTMLPurifier_Context object.
      */
     abstract public function validate($string, $config, $context);
 
     /**
      * Convenience method that parses a string as if it were CDATA.
      *
      * This method process a string in the manner specified at
      * <http://www.w3.org/TR/html4/types.html#h-6.2> by removing
      * leading and trailing whitespace, ignoring line feeds, and replacing
      * carriage returns and tabs with spaces.  While most useful for HTML
      * attributes specified as CDATA, it can also be applied to most CSS
      * values.
      *
      * @note This method is not entirely standards compliant, as trim() removes
      *       more types of whitespace than specified in the spec. In practice,
      *       this is rarely a problem, as those extra characters usually have
      *       already been removed by HTMLPurifier_Encoder.
      *
      * @warning This processing is inconsistent with XML's whitespace handling
      *          as specified by section 3.3.3 and referenced XHTML 1.0 section
      *          4.7.  However, note that we are NOT necessarily
      *          parsing XML, thus, this behavior may still be correct. We
      *          assume that newlines have been normalized.
      */
     public function parseCDATA($string)
     {
         $string = trim($string);
         $string = str_replace(array("\n", "\t", "\r"), ' ', $string);
         return $string;
     }
 
     /**
      * Factory method for creating this class from a string.
      * @param string $string String construction info
      * @return HTMLPurifier_AttrDef Created AttrDef object corresponding to $string
      */
     public function make($string)
     {
         // default implementation, return a flyweight of this object.
         // If $string has an effect on the returned object (i.e. you
         // need to overload this method), it is best
         // to clone or instantiate new copies. (Instantiation is safer.)
         return $this;
     }
 
     /**
      * Removes spaces from rgb(0, 0, 0) so that shorthand CSS properties work
      * properly. THIS IS A HACK!
      * @param string $string a CSS colour definition
      * @return string
      */
     protected function mungeRgb($string)
     {
         $p = '\s*(\d+(\.\d+)?([%]?))\s*';
 
         if (preg_match('/(rgba|hsla)\(/', $string)) {
             return preg_replace('/(rgba|hsla)\('.$p.','.$p.','.$p.','.$p.'\)/', '\1(\2,\5,\8,\11)', $string);
         }
 
         return preg_replace('/(rgb|hsl)\('.$p.','.$p.','.$p.'\)/', '\1(\2,\5,\8)', $string);
     }
 
     /**
      * Parses a possibly escaped CSS string and returns the "pure"
      * version of it.
      */
     protected function expandCSSEscape($string)
     {
         // flexibly parse it
         $ret = '';
         for ($i = 0, $c = strlen($string); $i < $c; $i++) {
             if ($string[$i] === '\\') {
                 $i++;
                 if ($i >= $c) {
                     $ret .= '\\';
                     break;
                 }
                 if (ctype_xdigit($string[$i])) {
                     $code = $string[$i];
                     for ($a = 1, $i++; $i < $c && $a < 6; $i++, $a++) {
                         if (!ctype_xdigit($string[$i])) {
                             break;
                         }
                         $code .= $string[$i];
                     }
                     // We have to be extremely careful when adding
                     // new characters, to make sure we're not breaking
                     // the encoding.
                     $char = HTMLPurifier_Encoder::unichr(hexdec($code));
                     if (HTMLPurifier_Encoder::cleanUTF8($char) === '') {
                         continue;
                     }
                     $ret .= $char;
                     if ($i < $c && trim($string[$i]) !== '') {
                         $i--;
                     }
                     continue;
                 }
                 if ($string[$i] === "\n") {
                     continue;
                 }
             }
             $ret .= $string[$i];
         }
         return $ret;
     }
 }
 
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