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      * Lookup of namespace shortcuts to full namespace names.
  24      */
  25     protected $nsLookup;
  26
  27     /**
  28      * List of attributes the extension adds to the generic xc namespace,
  29      * helps prevent naming conflicts.
  30      */
  31     protected $xcAttr = array();
  32     public function getXCAttributesDefined() {
  33         return $this->xcAttr;
  34     }
  35
  36
  37     /**
  38      * Defines a filter that processes a DOMDocument.
  39      * @note Return is not used as objects are passed "by reference", and
  40      *       thus edits we make will be globally reflected.
  41      * @param $dom DOMDocument to process
  42      * @param $page XHTMLCompiler_Page object representing the context
  43      * @param $manager Currently running XHTMLCompiler_FilterManager
  44      */
  45     abstract public function process(DOMDocument $dom, $page, $manager);
  46
  47     /**
  48      * Performs common initialization of DOM and XPath
  49      * @note This must be called before you can use any of the convenience
  50      *       functions.
  51      */
  52     public function setup($dom) {
  53         $this->dom = $dom;
  54         $this->xpath = new DOMXPath($dom);
  55         // defaults
  56         $ns['html'] = "http://www.w3.org/1999/xhtml";
  57         $ns['xml']  = "http://www.w3.org/XML/1998/namespace";
  58         $this->ns = $ns['xc'] = "urn:xhtml-compiler";
  59         if (isset($this->prefix)) {
  60             if ($this->prefix == 'html' || $this->prefix == 'xc') {
  61                 throw new Exception('Prefix for ' . get_class($this) .
  62                     'may not be the reserved ' . $this->prefix);
  63             }
  64             $this->ns = $ns[$this->prefix] = "urn:xhtml-compiler:" . $this->name;
  65         }
  66         foreach ($ns as $prefix => $uri) {
  67             $this->xpath->registerNamespace($prefix, $uri);
  68         }
  69         $this->nsLookup = $ns;
  70     }
  71
  72     /**
  73      * XPath object for the current DOM (private: use query() to use it)
  74      * @todo Implement all member functions for this
  75      */
  76     private $xpath;
  77
  78     /**
  79      * Current DOMDocument (private: use the instance passed to you via parameter)
  80      */
  81     private $dom;
  82
  83     /**
  84      * Querys a DOM with an XPath expression
  85      * @param $expr XPath expression to evaluate
  86      * @param $context Context node
  87      */
  88     protected function query($expr, $context = false) {
  89         if (!$this->dom) throw new Exception('Filter must be setup before using convenience functions');
  90         if (!$context) return $this->xpath->query($expr);
  91         return $this->xpath->query($expr, $context);
  92     }
  93
  94     /**
  95      * Retrieves a namespaced attribute from an element, and then deletes it.
  96      * @note This is best for proprietary attributes that, once you grab
  97      *       their data, they should be removed from the DOM for validation's
  98      *       sake.
  99      * @param $node Node to remove attribute from
 100      * @param $ns Namespace of attribute
 101      * @param $name Name of attribute
 102      * or
 103      * @param $node Node to remove attribute from
 104      * @param $name Name of attribute
 105      */
 106     protected function confiscateAttr($node, $ns_or_name, $name = null) {
 107         if (is_null($name)) {
 108             $name = $ns_or_name;
 109             $value = $node->getAttribute($name);
 110             $node->removeAttribute($name);
 111         } else {
 112             $ns = $ns_or_name;
 113             if (isset($this->nsLookup[$ns])) $ns = $this->nsLookup[$ns];
 114             $value = $node->getAttributeNS($ns, $name);
 115             $node->removeAttributeNS($ns, $name);
 116         }
 117         return $value;
 118     }
 119 }