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 generic xc 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, $manager);
  41
  42     /**
  43      * Performs common initialization of DOM and XPath
  44      * @note This must be called before you can use any of the convenience
  45      *       functions.
  46      */
  47     public function setup($dom) {
  48         $this->dom = $dom;
  49         $this->xpath = new DOMXPath($dom);
  50         // defaults
  51         $ns['html'] = "http://www.w3.org/1999/xhtml";
  52         $this->ns = $ns['xc'] = "urn:xhtml-compiler";
  53         if (isset($this->prefix)) {
  54             if ($this->prefix == 'html' || $this->prefix == 'xc') {
  55                 throw new Exception('Prefix for ' . get_class($this) .
  56                     'may not be the reserved ' . $this->prefix);
  57             }
  58             $this->ns = $ns[$this->prefix] = "urn:xhtml-compiler:" . $this->name;
  59         }
  60         foreach ($ns as $prefix => $uri) {
  61             $this->xpath->registerNamespace($prefix, $uri);
  62         }
  63     }
  64
  65     /**
  66      * XPath object for the current DOM (private: use query() to use it)
  67      * @todo Implement all member functions for this
  68      */
  69     private $xpath;
  70
  71     /**
  72      * Current DOMDocument (private: use the instance passed to you via parameter)
  73      */
  74     private $dom;
  75
  76     /**
  77      * Querys a DOM with an XPath expression
  78      * @param $expr XPath expression to evaluate
  79      * @param $context Context node
  80      */
  81     protected function query($expr, $context = false) {
  82         if (!$this->dom) throw new Exception('Filter must be setup before using convenience functions');
  83         if (!$context) return $this->xpath->query($expr);
  84         return $this->xpath->query($expr, $context);
  85     }
  86
  87     /**
  88      * Retrieves a namespaced attribute from an element, and then deletes it.
  89      * @note This is best for proprietary attributes that, once you grab
  90      *       their data, they should be removed from the DOM for validation's
  91      *       sake.
  92      * @param $node Node to remove attribute from
  93      * @param $ns Namespace of attribute
  94      * @param $name Name of attribute
  95      */
  96     protected function confiscateAttr($node, $ns, $name) {
  97         $value = $node->getAttributeNS($ns, $name);
  98         $node->removeAttributeNS($ns, $name);
  99         return $value;
 100     }
 101 }
 102
 103 ?>