1 : <?php
2 :
3 : /**
4 : * Takes tokens makes them well-formed (balance end tags, etc.)
5 : */
6 1 : class HTMLPurifier_Strategy_MakeWellFormed extends HTMLPurifier_Strategy
7 : {
8 :
9 : /**
10 : * Locally shared variable references
11 : */
12 : protected $inputTokens, $inputIndex, $outputTokens, $currentNesting,
13 : $currentInjector, $injectors;
14 :
15 : public function execute($tokens, $config, $context) {
16 :
17 2 : $definition = $config->getHTMLDefinition();
18 :
19 : // local variables
20 2 : $result = array();
21 2 : $generator = new HTMLPurifier_Generator($config, $context);
22 2 : $escape_invalid_tags = $config->get('Core', 'EscapeInvalidTags');
23 2 : $e = $context->get('ErrorCollector', true);
24 :
25 : // member variables
26 2 : $this->currentNesting = array();
27 2 : $this->inputIndex = false;
28 2 : $this->inputTokens =& $tokens;
29 2 : $this->outputTokens =& $result;
30 :
31 : // context variables
32 2 : $context->register('CurrentNesting', $this->currentNesting);
33 2 : $context->register('InputIndex', $this->inputIndex);
34 2 : $context->register('InputTokens', $tokens);
35 :
36 : // -- begin INJECTOR --
37 :
38 2 : $this->injectors = array();
39 :
40 2 : $injectors = $config->getBatch('AutoFormat');
41 2 : $def_injectors = $definition->info_injector;
42 2 : $custom_injectors = $injectors['Custom'];
43 2 : unset($injectors['Custom']); // special case
44 2 : foreach ($injectors as $injector => $b) {
45 2 : $injector = "HTMLPurifier_Injector_$injector";
46 2 : if (!$b) continue;
47 : $this->injectors[] = new $injector;
48 : }
49 2 : foreach ($def_injectors as $injector) {
50 : // assumed to be objects
51 : $this->injectors[] = $injector;
52 : }
53 2 : foreach ($custom_injectors as $injector) {
54 : if (is_string($injector)) {
55 : $injector = "HTMLPurifier_Injector_$injector";
56 : $injector = new $injector;
57 : }
58 : $this->injectors[] = $injector;
59 : }
60 :
61 : // array index of the injector that resulted in an array
62 : // substitution. This enables processTokens() to know which
63 : // injectors are affected by the added tokens and which are
64 : // not (namely, the ones after the current injector are not
65 : // affected)
66 2 : $this->currentInjector = false;
67 :
68 : // give the injectors references to the definition and context
69 : // variables for performance reasons
70 2 : foreach ($this->injectors as $i => $injector) {
71 : $error = $injector->prepare($config, $context);
72 : if (!$error) continue;
73 : array_splice($this->injectors, $i, 1); // rm the injector
74 : trigger_error("Cannot enable {$injector->name} injector because $error is not allowed", E_USER_WARNING);
75 : }
76 :
77 : // warning: most foreach loops follow the convention $i => $injector.
78 : // Don't define these as loop-wide variables, please!
79 :
80 : // -- end INJECTOR --
81 :
82 2 : $token = false;
83 2 : $context->register('CurrentToken', $token);
84 :
85 : // isset is in loop because $tokens size changes during loop exec
86 2 : for ($this->inputIndex = 0; isset($tokens[$this->inputIndex]); $this->inputIndex++) {
87 :
88 : // if all goes well, this token will be passed through unharmed
89 2 : $token = $tokens[$this->inputIndex];
90 :
91 : //printTokens($tokens, $this->inputIndex);
92 :
93 2 : foreach ($this->injectors as $injector) {
94 : if ($injector->skip > 0) $injector->skip--;
95 : }
96 :
97 : // quick-check: if it's not a tag, no need to process
98 2 : if (empty( $token->is_tag )) {
99 2 : if ($token instanceof HTMLPurifier_Token_Text) {
100 : // injector handler code; duplicated for performance reasons
101 2 : foreach ($this->injectors as $i => $injector) {
102 : if (!$injector->skip) $injector->handleText($token);
103 : if (is_array($token)) {
104 : $this->currentInjector = $i;
105 : break;
106 : }
107 : }
108 2 : }
109 2 : $this->processToken($token, $config, $context);
110 2 : continue;
111 : }
112 :
113 2 : $info = $definition->info[$token->name]->child;
114 :
115 : // quick tag checks: anything that's *not* an end tag
116 2 : $ok = false;
117 2 : if ($info->type === 'empty' && $token instanceof HTMLPurifier_Token_Start) {
118 : // test if it claims to be a start tag but is empty
119 : $token = new HTMLPurifier_Token_Empty($token->name, $token->attr);
120 : $ok = true;
121 2 : } elseif ($info->type !== 'empty' && $token instanceof HTMLPurifier_Token_Empty) {
122 : // claims to be empty but really is a start tag
123 : $token = array(
124 1 : new HTMLPurifier_Token_Start($token->name, $token->attr),
125 1 : new HTMLPurifier_Token_End($token->name)
126 1 : );
127 1 : $ok = true;
128 2 : } elseif ($token instanceof HTMLPurifier_Token_Empty) {
129 : // real empty token
130 2 : $ok = true;
131 2 : } elseif ($token instanceof HTMLPurifier_Token_Start) {
132 : // start tag
133 :
134 : // ...unless they also have to close their parent
135 2 : if (!empty($this->currentNesting)) {
136 :
137 2 : $parent = array_pop($this->currentNesting);
138 2 : $parent_info = $definition->info[$parent->name];
139 :
140 : // this can be replaced with a more general algorithm:
141 : // if the token is not allowed by the parent, auto-close
142 : // the parent
143 2 : if (!isset($parent_info->child->elements[$token->name])) {
144 : if ($e) $e->send(E_NOTICE, 'Strategy_MakeWellFormed: Tag auto closed', $parent);
145 : // close the parent, then re-loop to reprocess token
146 : $result[] = new HTMLPurifier_Token_End($parent->name);
147 : $this->inputIndex--;
148 : continue;
149 : }
150 :
151 2 : $this->currentNesting[] = $parent; // undo the pop
152 2 : }
153 2 : $ok = true;
154 2 : }
155 :
156 : // injector handler code; duplicated for performance reasons
157 2 : if ($ok) {
158 2 : foreach ($this->injectors as $i => $injector) {
159 : if (!$injector->skip) $injector->handleElement($token);
160 : if (is_array($token)) {
161 : $this->currentInjector = $i;
162 : break;
163 : }
164 : }
165 2 : $this->processToken($token, $config, $context);
166 2 : continue;
167 : }
168 :
169 : // sanity check: we should be dealing with a closing tag
170 2 : if (!$token instanceof HTMLPurifier_Token_End) continue;
171 :
172 : // make sure that we have something open
173 2 : if (empty($this->currentNesting)) {
174 : if ($escape_invalid_tags) {
175 : if ($e) $e->send(E_WARNING, 'Strategy_MakeWellFormed: Unnecessary end tag to text');
176 : $result[] = new HTMLPurifier_Token_Text(
177 : $generator->generateFromToken($token)
178 : );
179 : } elseif ($e) {
180 : $e->send(E_WARNING, 'Strategy_MakeWellFormed: Unnecessary end tag removed');
181 : }
182 : continue;
183 : }
184 :
185 : // first, check for the simplest case: everything closes neatly
186 2 : $current_parent = array_pop($this->currentNesting);
187 2 : if ($current_parent->name == $token->name) {
188 2 : $result[] = $token;
189 2 : foreach ($this->injectors as $i => $injector) {
190 : $injector->notifyEnd($token);
191 : }
192 2 : continue;
193 : }
194 :
195 : // okay, so we're trying to close the wrong tag
196 :
197 : // undo the pop previous pop
198 : $this->currentNesting[] = $current_parent;
199 :
200 : // scroll back the entire nest, trying to find our tag.
201 : // (feature could be to specify how far you'd like to go)
202 : $size = count($this->currentNesting);
203 : // -2 because -1 is the last element, but we already checked that
204 : $skipped_tags = false;
205 : for ($i = $size - 2; $i >= 0; $i--) {
206 : if ($this->currentNesting[$i]->name == $token->name) {
207 : // current nesting is modified
208 : $skipped_tags = array_splice($this->currentNesting, $i);
209 : break;
210 : }
211 : }
212 :
213 : // we still didn't find the tag, so remove
214 : if ($skipped_tags === false) {
215 : if ($escape_invalid_tags) {
216 : $result[] = new HTMLPurifier_Token_Text(
217 : $generator->generateFromToken($token)
218 : );
219 : if ($e) $e->send(E_WARNING, 'Strategy_MakeWellFormed: Stray end tag to text');
220 : } elseif ($e) {
221 : $e->send(E_WARNING, 'Strategy_MakeWellFormed: Stray end tag removed');
222 : }
223 : continue;
224 : }
225 :
226 : // okay, we found it, close all the skipped tags
227 : // note that skipped tags contains the element we need closed
228 : for ($i = count($skipped_tags) - 1; $i >= 0; $i--) {
229 : // please don't redefine $i!
230 : if ($i && $e && !isset($skipped_tags[$i]->armor['MakeWellFormed_TagClosedError'])) {
231 : $e->send(E_NOTICE, 'Strategy_MakeWellFormed: Tag closed by element end', $skipped_tags[$i]);
232 : }
233 : $result[] = $new_token = new HTMLPurifier_Token_End($skipped_tags[$i]->name);
234 : foreach ($this->injectors as $injector) {
235 : $injector->notifyEnd($new_token);
236 : }
237 : }
238 :
239 : }
240 :
241 2 : $context->destroy('CurrentNesting');
242 2 : $context->destroy('InputTokens');
243 2 : $context->destroy('InputIndex');
244 2 : $context->destroy('CurrentToken');
245 :
246 : // we're at the end now, fix all still unclosed tags (this is
247 : // duplicated from the end of the loop with some slight modifications)
248 : // not using $skipped_tags since it would invariably be all of them
249 2 : if (!empty($this->currentNesting)) {
250 : for ($i = count($this->currentNesting) - 1; $i >= 0; $i--) {
251 : // please don't redefine $i!
252 : if ($e && !isset($this->currentNesting[$i]->armor['MakeWellFormed_TagClosedError'])) {
253 : $e->send(E_NOTICE, 'Strategy_MakeWellFormed: Tag closed by document end', $this->currentNesting[$i]);
254 : }
255 : $result[] = $new_token = new HTMLPurifier_Token_End($this->currentNesting[$i]->name);
256 : foreach ($this->injectors as $injector) {
257 : $injector->notifyEnd($new_token);
258 : }
259 : }
260 : }
261 :
262 2 : unset($this->outputTokens, $this->injectors, $this->currentInjector,
263 : $this->currentNesting, $this->inputTokens, $this->inputIndex);
264 :
265 2 : return $result;
266 : }
267 :
268 : function processToken($token, $config, $context) {
269 2 : if (is_array($token)) {
270 : // the original token was overloaded by an injector, time
271 : // to some fancy acrobatics
272 :
273 : // $this->inputIndex is decremented so that the entire set gets
274 : // re-processed
275 1 : array_splice($this->inputTokens, $this->inputIndex--, 1, $token);
276 :
277 : // adjust the injector skips based on the array substitution
278 1 : if ($this->injectors) {
279 0 : $offset = count($token);
280 0 : for ($i = 0; $i <= $this->currentInjector; $i++) {
281 : // because of the skip back, we need to add one more
282 : // for uninitialized injectors. I'm not exactly
283 : // sure why this is the case, but I think it has to
284 : // do with the fact that we're decrementing skips
285 : // before re-checking text
286 0 : if (!$this->injectors[$i]->skip) $this->injectors[$i]->skip++;
287 0 : $this->injectors[$i]->skip += $offset;
288 0 : }
289 0 : }
290 2 : } elseif ($token) {
291 : // regular case
292 2 : $this->outputTokens[] = $token;
293 2 : if ($token instanceof HTMLPurifier_Token_Start) {
294 2 : $this->currentNesting[] = $token;
295 2 : } elseif ($token instanceof HTMLPurifier_Token_End) {
296 0 : array_pop($this->currentNesting); // not actually used
297 0 : }
298 2 : }
299 2 : }
300 :
301 : }
302 :
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