library/HTMLPurifier/ElementDef.php

   1 <?php
   2
   3 /**
   4  * Structure that stores an HTML element definition. Used by
   5  * HTMLPurifier_HTMLDefinition and HTMLPurifier_HTMLModule.
   6  * @note This class is inspected by HTMLPurifier_Printer_HTMLDefinition.
   7  *       Please update that class too.
   8  * @warning If you add new properties to this class, you MUST update
   9  *          the mergeIn() method.
  10  */
  11 class HTMLPurifier_ElementDef
  12 {
  13
  14     /**
  15      * Does the definition work by itself, or is it created solely
  16      * for the purpose of merging into another definition?
  17      */
  18     public $standalone = true;
  19
  20     /**
  21      * Associative array of attribute name to HTMLPurifier_AttrDef
  22      * @note Before being processed by HTMLPurifier_AttrCollections
  23      *       when modules are finalized during
  24      *       HTMLPurifier_HTMLDefinition->setup(), this array may also
  25      *       contain an array at index 0 that indicates which attribute
  26      *       collections to load into the full array. It may also
  27      *       contain string indentifiers in lieu of HTMLPurifier_AttrDef,
  28      *       see HTMLPurifier_AttrTypes on how they are expanded during
  29      *       HTMLPurifier_HTMLDefinition->setup() processing.
  30      */
  31     public $attr = array();
  32
  33     /**
  34      * Indexed list of tag's HTMLPurifier_AttrTransform to be done before validation
  35      */
  36     public $attr_transform_pre = array();
  37
  38     /**
  39      * Indexed list of tag's HTMLPurifier_AttrTransform to be done after validation
  40      */
  41     public $attr_transform_post = array();
  42
  43     /**
  44      * HTMLPurifier_ChildDef of this tag.
  45      */
  46     public $child;
  47
  48     /**
  49      * Abstract string representation of internal ChildDef rules. See
  50      * HTMLPurifier_ContentSets for how this is parsed and then transformed
  51      * into an HTMLPurifier_ChildDef.
  52      * @warning This is a temporary variable that is not available after
  53      *      being processed by HTMLDefinition
  54      */
  55     public $content_model;
  56
  57     /**
  58      * Value of $child->type, used to determine which ChildDef to use,
  59      * used in combination with $content_model.
  60      * @warning This must be lowercase
  61      * @warning This is a temporary variable that is not available after
  62      *      being processed by HTMLDefinition
  63      */
  64     public $content_model_type;
  65
  66
  67
  68     /**
  69      * Does the element have a content model (#PCDATA | Inline)*? This
  70      * is important for chameleon ins and del processing in
  71      * HTMLPurifier_ChildDef_Chameleon. Dynamically set: modules don't
  72      * have to worry about this one.
  73      */
  74     public $descendants_are_inline = false;
  75
  76     /**
  77      * List of the names of required attributes this element has. Dynamically
  78      * populated by HTMLPurifier_HTMLDefinition::getElement
  79      */
  80     public $required_attr = array();
  81
  82     /**
  83      * Lookup table of tags excluded from all descendants of this tag.
  84      * @note SGML permits exclusions for all descendants, but this is
  85      *       not possible with DTDs or XML Schemas. W3C has elected to
  86      *       use complicated compositions of content_models to simulate
  87      *       exclusion for children, but we go the simpler, SGML-style
  88      *       route of flat-out exclusions, which correctly apply to
  89      *       all descendants and not just children. Note that the XHTML
  90      *       Modularization Abstract Modules are blithely unaware of such
  91      *       distinctions.
  92      */
  93     public $excludes = array();
  94
  95     /**
  96      * This tag is explicitly auto-closed by the following tags.
  97      */
  98     public $autoclose = array();
  99
 100     /**
 101      * Whether or not this is a formatting element affected by the
 102      * "Active Formatting Elements" algorithm.
 103      */
 104     public $formatting;
 105
 106     /**
 107      * Low-level factory constructor for creating new standalone element defs
 108      */
 109     public static function create($content_model, $content_model_type, $attr) {
 110         $def = new HTMLPurifier_ElementDef();
 111         $def->content_model = $content_model;
 112         $def->content_model_type = $content_model_type;
 113         $def->attr = $attr;
 114         return $def;
 115     }
 116
 117     /**
 118      * Merges the values of another element definition into this one.
 119      * Values from the new element def take precedence if a value is
 120      * not mergeable.
 121      */
 122     public function mergeIn($def) {
 123
 124         // later keys takes precedence
 125         foreach($def->attr as $k => $v) {
 126             if ($k === 0) {
 127                 // merge in the includes
 128                 // sorry, no way to override an include
 129                 foreach ($v as $v2) {
 130                     $this->attr[0][] = $v2;
 131                 }
 132                 continue;
 133             }
 134             if ($v === false) {
 135                 if (isset($this->attr[$k])) unset($this->attr[$k]);
 136                 continue;
 137             }
 138             $this->attr[$k] = $v;
 139         }
 140         $this->_mergeAssocArray($this->attr_transform_pre, $def->attr_transform_pre);
 141         $this->_mergeAssocArray($this->attr_transform_post, $def->attr_transform_post);
 142         $this->_mergeAssocArray($this->excludes, $def->excludes);
 143
 144         if(!empty($def->content_model)) {
 145             $this->content_model .= ' | ' . $def->content_model;
 146             $this->child = false;
 147         }
 148         if(!empty($def->content_model_type)) {
 149             $this->content_model_type = $def->content_model_type;
 150             $this->child = false;
 151         }
 152         if(!is_null($def->child)) $this->child = $def->child;
 153         if(!is_null($def->formatting)) $this->formatting = $def->formatting;
 154         if($def->descendants_are_inline) $this->descendants_are_inline = $def->descendants_are_inline;
 155
 156     }
 157
 158     /**
 159      * Merges one array into another, removes values which equal false
 160      * @param $a1 Array by reference that is merged into
 161      * @param $a2 Array that merges into $a1
 162      */
 163     private function _mergeAssocArray(&$a1, $a2) {
 164         foreach ($a2 as $k => $v) {
 165             if ($v === false) {
 166                 if (isset($a1[$k])) unset($a1[$k]);
 167                 continue;
 168             }
 169             $a1[$k] = $v;
 170         }
 171     }
 172
 173 }
 174
 175 // vim: et sw=4 sts=4