XHTMLCompiler/DOMFilter.php

   1 <?php
   2
   3 /**
   4  * Represents a filter that performs processing on documents. Read-only.
   5  */
   6 abstract class XHTMLCompiler_DOMFilter extends XHTMLCompiler_Filter
   7 {
   8
   9     /**
  10      * If set, DOMFilter will allocate a namespace for the filter
  11      * and assign it to this prefix.
  12      * @warning May not be 'html' or 'xc', because these are already
  13      *          allocated for the core namespaces.
  14      */
  15     protected $prefix;
  16
  17     /**
  18      * Allocated namespace for the filter, or default 'xc' one.
  19      */
  20     protected $ns;
  21
  22     /**
  23      * List of attributes the extension adds to the namespace,
  24      * helps prevent naming conflicts.
  25      */
  26     protected $xcAttr = array();
  27     public function getXCAttributesDefined() {
  28         return $this->xcAttr;
  29     }
  30
  31
  32     /**
  33      * Defines a filter that processes a DOMDocument.
  34      * @note Return is not used as objects are passed "by reference", and
  35      *       thus edits we make will be globally reflected.
  36      * @param $dom DOMDocument to process
  37      * @param $page XHTMLCompiler_Page object representing the context
  38      * @param $manager Currently running XHTMLCompiler_FilterManager
  39      */
  40     abstract public function process(DOMDocument $dom, $page, $manager);
  41
  42     /**
  43      * Performs common initialization of DOM and XPath
  44      */
  45     public function setup($dom) {
  46         $this->dom = $dom;
  47         $this->xpath = new DOMXPath($dom);
  48         // defaults
  49         $ns['html'] = "http://www.w3.org/1999/xhtml";
  50         $this->ns = $ns['xc'] = "urn:xhtml-compiler";
  51         if (isset($this->prefix)) {
  52             if ($this->prefix == 'html' || $this->prefix == 'xc') {
  53                 throw new Exception('Prefix for ' . get_class($this) .
  54                     'may not be the reserved ' . $this->prefix);
  55             }
  56             $this->ns = $ns[$this->prefix] = "urn:xhtml-compiler:" . $this->name;
  57         }
  58         foreach ($ns as $prefix => $uri) {
  59             $this->xpath->registerNamespace($prefix, $uri);
  60         }
  61     }
  62
  63     /**
  64      * XPath object for the current DOM
  65      */
  66     private $xpath;
  67
  68     /**
  69      * Current DOMDocument
  70      */
  71     private $dom;
  72
  73     /**
  74      * Querys a DOM with an XPath expression
  75      * @param $expr XPath expression to evaluate
  76      * @param $context Context node
  77      */
  78     protected function query($expr, $context = false) {
  79         if (!$this->dom) throw new Exception('Filter must be setup before using convenience functions');
  80         if (!$context) return $this->xpath->query($expr);
  81         return $this->xpath->query($expr, $context);
  82     }
  83
  84     /**
  85      * Retrieves a namespaced attribute from an element, and then deletes it.
  86      * @note This is best for proprietary attributes that, once you grab
  87      *       their data, they should be removed from the DOM for validation's
  88      *       sake.
  89      * @param $node Node to remove attribute from
  90      * @param $ns Namespace of attribute
  91      * @param $name Name of attribute
  92      */
  93     protected function confiscateAttr($node, $ns, $name) {
  94         $value = $node->getAttributeNS($ns, $name);
  95         $node->removeAttributeNS($ns, $name);
  96         return $value;
  97     }
  98 }
  99
 100 ?>