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vendor/ezyang/htmlpurifier/library/HTMLPurifier/AttrDef/CSS.php 3.38 KB
abf1649b   andryeyev   Чистая установка ...
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  <?php
  
  /**
   * Validates the HTML attribute style, otherwise known as CSS.
   * @note We don't implement the whole CSS specification, so it might be
   *       difficult to reuse this component in the context of validating
   *       actual stylesheet declarations.
   * @note If we were really serious about validating the CSS, we would
   *       tokenize the styles and then parse the tokens. Obviously, we
   *       are not doing that. Doing that could seriously harm performance,
   *       but would make these components a lot more viable for a CSS
   *       filtering solution.
   */
  class HTMLPurifier_AttrDef_CSS extends HTMLPurifier_AttrDef
  {
  
      /**
       * @param string $css
       * @param HTMLPurifier_Config $config
       * @param HTMLPurifier_Context $context
       * @return bool|string
       */
      public function validate($css, $config, $context)
      {
          $css = $this->parseCDATA($css);
  
          $definition = $config->getCSSDefinition();
  
          // we're going to break the spec and explode by semicolons.
          // This is because semicolon rarely appears in escaped form
          // Doing this is generally flaky but fast
          // IT MIGHT APPEAR IN URIs, see HTMLPurifier_AttrDef_CSSURI
          // for details
  
          $declarations = explode(';', $css);
          $propvalues = array();
  
          /**
           * Name of the current CSS property being validated.
           */
          $property = false;
          $context->register('CurrentCSSProperty', $property);
  
          foreach ($declarations as $declaration) {
              if (!$declaration) {
                  continue;
              }
              if (!strpos($declaration, ':')) {
                  continue;
              }
              list($property, $value) = explode(':', $declaration, 2);
              $property = trim($property);
              $value = trim($value);
              $ok = false;
              do {
                  if (isset($definition->info[$property])) {
                      $ok = true;
                      break;
                  }
                  if (ctype_lower($property)) {
                      break;
                  }
                  $property = strtolower($property);
                  if (isset($definition->info[$property])) {
                      $ok = true;
                      break;
                  }
              } while (0);
              if (!$ok) {
                  continue;
              }
              // inefficient call, since the validator will do this again
              if (strtolower(trim($value)) !== 'inherit') {
                  // inherit works for everything (but only on the base property)
                  $result = $definition->info[$property]->validate(
                      $value,
                      $config,
                      $context
                  );
              } else {
                  $result = 'inherit';
              }
              if ($result === false) {
                  continue;
              }
              $propvalues[$property] = $result;
          }
  
          $context->destroy('CurrentCSSProperty');
  
          // procedure does not write the new CSS simultaneously, so it's
          // slightly inefficient, but it's the only way of getting rid of
          // duplicates. Perhaps config to optimize it, but not now.
  
          $new_declarations = '';
          foreach ($propvalues as $prop => $value) {
              $new_declarations .= "$prop:$value;";
          }
  
          return $new_declarations ? $new_declarations : false;
  
      }
  
  }
  
  // vim: et sw=4 sts=4