4 * Injects tokens into the document while parsing for well-formedness.
5 * This enables "formatter-like" functionality such as auto-paragraphing,
6 * smiley-ification and linkification to take place.
8 * A note on how handlers create changes; this is done by assigning a new
9 * value to the $token reference. These values can take a variety of forms and
10 * are best described HTMLPurifier_Strategy_MakeWellFormed->processToken()
13 * @todo Allow injectors to request a re-run on their output. This
14 * would help if an operation is recursive.
16 abstract class HTMLPurifier_Injector
20 * Advisory name of injector, this is for friendly error messages
25 * Instance of HTMLPurifier_HTMLDefinition
27 protected $htmlDefinition;
30 * Reference to CurrentNesting variable in Context. This is an array
31 * list of tokens that we are currently "inside"
33 protected $currentNesting;
36 * Reference to InputTokens variable in Context. This is an array
37 * list of the input tokens that are being processed.
39 protected $inputTokens;
42 * Reference to InputIndex variable in Context. This is an integer
43 * array index for $this->inputTokens that indicates what token
44 * is currently being processed.
46 protected $inputIndex;
49 * Array of elements and attributes this injector creates and therefore
50 * need to be allowed by the definition. Takes form of
51 * array('element' => array('attr', 'attr2'), 'element2')
53 public $needed = array();
56 * Index of inputTokens to rewind to.
58 protected $rewind = false;
61 * Rewind to a spot to re-perform processing. This is useful if you
62 * deleted a node, and now need to see if this change affected any
63 * earlier nodes. Rewinding does not affect other injectors, and can
64 * result in infinite loops if not used carefully.
65 * @warning HTML Purifier will prevent you from fast-forwarding with this
68 public function rewind($index) {
69 $this->rewind
= $index;
73 * Retrieves rewind, and then unsets it.
75 public function getRewind() {
77 $this->rewind
= false;
82 * Prepares the injector by giving it the config and context objects:
83 * this allows references to important variables to be made within
84 * the injector. This function also checks if the HTML environment
85 * will work with the Injector (see checkNeeded()).
86 * @param $config Instance of HTMLPurifier_Config
87 * @param $context Instance of HTMLPurifier_Context
88 * @return Boolean false if success, string of missing needed element/attribute if failure
90 public function prepare($config, $context) {
91 $this->htmlDefinition
= $config->getHTMLDefinition();
92 // Even though this might fail, some unit tests ignore this and
93 // still test checkNeeded, so be careful. Maybe get rid of that
95 $result = $this->checkNeeded($config);
96 if ($result !== false) return $result;
97 $this->currentNesting
=& $context->get('CurrentNesting');
98 $this->inputTokens
=& $context->get('InputTokens');
99 $this->inputIndex
=& $context->get('InputIndex');
104 * This function checks if the HTML environment
105 * will work with the Injector: if p tags are not allowed, the
106 * Auto-Paragraphing injector should not be enabled.
107 * @param $config Instance of HTMLPurifier_Config
108 * @param $context Instance of HTMLPurifier_Context
109 * @return Boolean false if success, string of missing needed element/attribute if failure
111 public function checkNeeded($config) {
112 $def = $config->getHTMLDefinition();
113 foreach ($this->needed
as $element => $attributes) {
114 if (is_int($element)) $element = $attributes;
115 if (!isset($def->info
[$element])) return $element;
116 if (!is_array($attributes)) continue;
117 foreach ($attributes as $name) {
118 if (!isset($def->info
[$element]->attr
[$name])) return "$element.$name";
125 * Tests if the context node allows a certain element
126 * @param $name Name of element to test for
127 * @return True if element is allowed, false if it is not
129 public function allowsElement($name) {
130 if (!empty($this->currentNesting
)) {
131 $parent_token = array_pop($this->currentNesting
);
132 $this->currentNesting
[] = $parent_token;
133 $parent = $this->htmlDefinition
->info
[$parent_token->name
];
135 $parent = $this->htmlDefinition
->info_parent_def
;
137 if (!isset($parent->child
->elements
[$name]) ||
isset($parent->excludes
[$name])) {
144 * Iterator function, which starts with the next token and continues until
145 * you reach the end of the input tokens.
146 * @warning Please prevent previous references from interfering with this
147 * functions by setting $i = null beforehand!
148 * @param &$i Current integer index variable for inputTokens
149 * @param &$current Current token variable. Do NOT use $token, as that variable is also a reference
151 protected function forward(&$i, &$current) {
152 if ($i === null) $i = $this->inputIndex +
1;
154 if (!isset($this->inputTokens
[$i])) return false;
155 $current = $this->inputTokens
[$i];
160 * Similar to _forward, but accepts a third parameter $nesting (which
161 * should be initialized at 0) and stops when we hit the end tag
162 * for the node $this->inputIndex starts in.
164 protected function forwardUntilEndToken(&$i, &$current, &$nesting) {
165 $result = $this->forward($i, $current);
166 if (!$result) return false;
167 if ($nesting === null) $nesting = 0;
168 if ($current instanceof HTMLPurifier_Token_Start
) $nesting++
;
169 elseif ($current instanceof HTMLPurifier_Token_End
) {
170 if ($nesting <= 0) return false;
177 * Iterator function, starts with the previous token and continues until
178 * you reach the beginning of input tokens.
179 * @warning Please prevent previous references from interfering with this
180 * functions by setting $i = null beforehand!
181 * @param &$i Current integer index variable for inputTokens
182 * @param &$current Current token variable. Do NOT use $token, as that variable is also a reference
184 protected function backward(&$i, &$current) {
185 if ($i === null) $i = $this->inputIndex
- 1;
187 if ($i < 0) return false;
188 $current = $this->inputTokens
[$i];
193 * Initializes the iterator at the current position. Use in a do {} while;
194 * loop to force the _forward and _backward functions to start at the
196 * @warning Please prevent previous references from interfering with this
197 * functions by setting $i = null beforehand!
198 * @param &$i Current integer index variable for inputTokens
199 * @param &$current Current token variable. Do NOT use $token, as that variable is also a reference
201 protected function current(&$i, &$current) {
202 if ($i === null) $i = $this->inputIndex
;
203 $current = $this->inputTokens
[$i];
207 * Handler that is called when a text token is processed
209 public function handleText(&$token) {}
212 * Handler that is called when a start or empty token is processed
214 public function handleElement(&$token) {}
217 * Handler that is called when an end token is processed
219 public function handleEnd(&$token) {
220 $this->notifyEnd($token);
224 * Notifier that is called when an end token is processed
225 * @note This differs from handlers in that the token is read-only
228 public function notifyEnd($token) {}