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  1. <?php
  2. /**
  3. * Generates HTML from tokens.
  4. * @todo Refactor interface so that configuration/context is determined
  5. * upon instantiation, no need for messy generateFromTokens() calls
  6. * @todo Make some of the more internal functions protected, and have
  7. * unit tests work around that
  8. */
  9. class HTMLPurifier_Generator
  10. {
  11. /**
  12. * Whether or not generator should produce XML output.
  13. * @type bool
  14. */
  15. private $_xhtml = true;
  16. /**
  17. * :HACK: Whether or not generator should comment the insides of <script> tags.
  18. * @type bool
  19. */
  20. private $_scriptFix = false;
  21. /**
  22. * Cache of HTMLDefinition during HTML output to determine whether or
  23. * not attributes should be minimized.
  24. * @type HTMLPurifier_HTMLDefinition
  25. */
  26. private $_def;
  27. /**
  28. * Cache of %Output.SortAttr.
  29. * @type bool
  30. */
  31. private $_sortAttr;
  32. /**
  33. * Cache of %Output.FlashCompat.
  34. * @type bool
  35. */
  36. private $_flashCompat;
  37. /**
  38. * Cache of %Output.FixInnerHTML.
  39. * @type bool
  40. */
  41. private $_innerHTMLFix;
  42. /**
  43. * Stack for keeping track of object information when outputting IE
  44. * compatibility code.
  45. * @type array
  46. */
  47. private $_flashStack = array();
  48. /**
  49. * Configuration for the generator
  50. * @type HTMLPurifier_Config
  51. */
  52. protected $config;
  53. /**
  54. * @param HTMLPurifier_Config $config
  55. * @param HTMLPurifier_Context $context
  56. */
  57. public function __construct($config, $context)
  58. {
  59. $this->config = $config;
  60. $this->_scriptFix = $config->get('Output.CommentScriptContents');
  61. $this->_innerHTMLFix = $config->get('Output.FixInnerHTML');
  62. $this->_sortAttr = $config->get('Output.SortAttr');
  63. $this->_flashCompat = $config->get('Output.FlashCompat');
  64. $this->_def = $config->getHTMLDefinition();
  65. $this->_xhtml = $this->_def->doctype->xml;
  66. }
  67. /**
  68. * Generates HTML from an array of tokens.
  69. * @param HTMLPurifier_Token[] $tokens Array of HTMLPurifier_Token
  70. * @return string Generated HTML
  71. */
  72. public function generateFromTokens($tokens)
  73. {
  74. if (!$tokens) {
  75. return '';
  76. }
  77. // Basic algorithm
  78. $html = '';
  79. for ($i = 0, $size = count($tokens); $i < $size; $i++) {
  80. if ($this->_scriptFix && $tokens[$i]->name === 'script'
  81. && $i + 2 < $size && $tokens[$i+2] instanceof HTMLPurifier_Token_End) {
  82. // script special case
  83. // the contents of the script block must be ONE token
  84. // for this to work.
  85. $html .= $this->generateFromToken($tokens[$i++]);
  86. $html .= $this->generateScriptFromToken($tokens[$i++]);
  87. }
  88. $html .= $this->generateFromToken($tokens[$i]);
  89. }
  90. // Tidy cleanup
  91. if (extension_loaded('tidy') && $this->config->get('Output.TidyFormat')) {
  92. $tidy = new Tidy;
  93. $tidy->parseString(
  94. $html,
  95. array(
  96. 'indent'=> true,
  97. 'output-xhtml' => $this->_xhtml,
  98. 'show-body-only' => true,
  99. 'indent-spaces' => 2,
  100. 'wrap' => 68,
  101. ),
  102. 'utf8'
  103. );
  104. $tidy->cleanRepair();
  105. $html = (string) $tidy; // explicit cast necessary
  106. }
  107. // Normalize newlines to system defined value
  108. if ($this->config->get('Core.NormalizeNewlines')) {
  109. $nl = $this->config->get('Output.Newline');
  110. if ($nl === null) {
  111. $nl = PHP_EOL;
  112. }
  113. if ($nl !== "\n") {
  114. $html = str_replace("\n", $nl, $html);
  115. }
  116. }
  117. return $html;
  118. }
  119. /**
  120. * Generates HTML from a single token.
  121. * @param HTMLPurifier_Token $token HTMLPurifier_Token object.
  122. * @return string Generated HTML
  123. */
  124. public function generateFromToken($token)
  125. {
  126. if (!$token instanceof HTMLPurifier_Token) {
  127. trigger_error('Cannot generate HTML from non-HTMLPurifier_Token object', E_USER_WARNING);
  128. return '';
  129. } elseif ($token instanceof HTMLPurifier_Token_Start) {
  130. $attr = $this->generateAttributes($token->attr, $token->name);
  131. if ($this->_flashCompat) {
  132. if ($token->name == "object") {
  133. $flash = new stdclass();
  134. $flash->attr = $token->attr;
  135. $flash->param = array();
  136. $this->_flashStack[] = $flash;
  137. }
  138. }
  139. return '<' . $token->name . ($attr ? ' ' : '') . $attr . '>';
  140. } elseif ($token instanceof HTMLPurifier_Token_End) {
  141. $_extra = '';
  142. if ($this->_flashCompat) {
  143. if ($token->name == "object" && !empty($this->_flashStack)) {
  144. // doesn't do anything for now
  145. }
  146. }
  147. return $_extra . '</' . $token->name . '>';
  148. } elseif ($token instanceof HTMLPurifier_Token_Empty) {
  149. if ($this->_flashCompat && $token->name == "param" && !empty($this->_flashStack)) {
  150. $this->_flashStack[count($this->_flashStack)-1]->param[$token->attr['name']] = $token->attr['value'];
  151. }
  152. $attr = $this->generateAttributes($token->attr, $token->name);
  153. return '<' . $token->name . ($attr ? ' ' : '') . $attr .
  154. ( $this->_xhtml ? ' /': '' ) // <br /> v. <br>
  155. . '>';
  156. } elseif ($token instanceof HTMLPurifier_Token_Text) {
  157. return $this->escape($token->data, ENT_NOQUOTES);
  158. } elseif ($token instanceof HTMLPurifier_Token_Comment) {
  159. return '<!--' . $token->data . '-->';
  160. } else {
  161. return '';
  162. }
  163. }
  164. /**
  165. * Special case processor for the contents of script tags
  166. * @param HTMLPurifier_Token $token HTMLPurifier_Token object.
  167. * @return string
  168. * @warning This runs into problems if there's already a literal
  169. * --> somewhere inside the script contents.
  170. */
  171. public function generateScriptFromToken($token)
  172. {
  173. if (!$token instanceof HTMLPurifier_Token_Text) {
  174. return $this->generateFromToken($token);
  175. }
  176. // Thanks <http://lachy.id.au/log/2005/05/script-comments>
  177. $data = preg_replace('#//\s*$#', '', $token->data);
  178. return '<!--//--><![CDATA[//><!--' . "\n" . trim($data) . "\n" . '//--><!]]>';
  179. }
  180. /**
  181. * Generates attribute declarations from attribute array.
  182. * @note This does not include the leading or trailing space.
  183. * @param array $assoc_array_of_attributes Attribute array
  184. * @param string $element Name of element attributes are for, used to check
  185. * attribute minimization.
  186. * @return string Generated HTML fragment for insertion.
  187. */
  188. public function generateAttributes($assoc_array_of_attributes, $element = '')
  189. {
  190. $html = '';
  191. if ($this->_sortAttr) {
  192. ksort($assoc_array_of_attributes);
  193. }
  194. foreach ($assoc_array_of_attributes as $key => $value) {
  195. if (!$this->_xhtml) {
  196. // Remove namespaced attributes
  197. if (strpos($key, ':') !== false) {
  198. continue;
  199. }
  200. // Check if we should minimize the attribute: val="val" -> val
  201. if ($element && !empty($this->_def->info[$element]->attr[$key]->minimized)) {
  202. $html .= $key . ' ';
  203. continue;
  204. }
  205. }
  206. // Workaround for Internet Explorer innerHTML bug.
  207. // Essentially, Internet Explorer, when calculating
  208. // innerHTML, omits quotes if there are no instances of
  209. // angled brackets, quotes or spaces. However, when parsing
  210. // HTML (for example, when you assign to innerHTML), it
  211. // treats backticks as quotes. Thus,
  212. // <img alt="``" />
  213. // becomes
  214. // <img alt=`` />
  215. // becomes
  216. // <img alt='' />
  217. // Fortunately, all we need to do is trigger an appropriate
  218. // quoting style, which we do by adding an extra space.
  219. // This also is consistent with the W3C spec, which states
  220. // that user agents may ignore leading or trailing
  221. // whitespace (in fact, most don't, at least for attributes
  222. // like alt, but an extra space at the end is barely
  223. // noticeable). Still, we have a configuration knob for
  224. // this, since this transformation is not necesary if you
  225. // don't process user input with innerHTML or you don't plan
  226. // on supporting Internet Explorer.
  227. if ($this->_innerHTMLFix) {
  228. if (strpos($value, '`') !== false) {
  229. // check if correct quoting style would not already be
  230. // triggered
  231. if (strcspn($value, '"\' <>') === strlen($value)) {
  232. // protect!
  233. $value .= ' ';
  234. }
  235. }
  236. }
  237. $html .= $key.'="'.$this->escape($value).'" ';
  238. }
  239. return rtrim($html);
  240. }
  241. /**
  242. * Escapes raw text data.
  243. * @todo This really ought to be protected, but until we have a facility
  244. * for properly generating HTML here w/o using tokens, it stays
  245. * public.
  246. * @param string $string String data to escape for HTML.
  247. * @param int $quote Quoting style, like htmlspecialchars. ENT_NOQUOTES is
  248. * permissible for non-attribute output.
  249. * @return string escaped data.
  250. */
  251. public function escape($string, $quote = null)
  252. {
  253. // Workaround for APC bug on Mac Leopard reported by sidepodcast
  254. // http://htmlpurifier.org/phorum/read.php?3,4823,4846
  255. if ($quote === null) {
  256. $quote = ENT_COMPAT;
  257. }
  258. return htmlspecialchars($string, $quote, 'UTF-8');
  259. }
  260. }
  261. // vim: et sw=4 sts=4