| 1 | <?php |
| 2 | // $Id: path.inc,v 1.44 2009/08/02 06:48:24 webchick Exp $ |
| 3 | |
| 4 | /** |
| 5 | * @file |
| 6 | * Functions to handle paths in Drupal, including path aliasing. |
| 7 | * |
| 8 | * These functions are not loaded for cached pages, but modules that need |
| 9 | * to use them in hook_init() or hook exit() can make them available, by |
| 10 | * executing "drupal_bootstrap(DRUPAL_BOOTSTRAP_PATH);". |
| 11 | */ |
| 12 | |
| 13 | /** |
| 14 | * Initialize the $_GET['q'] variable to the proper normal path. |
| 15 | */ |
| 16 | function drupal_path_initialize() { |
| 17 | if (!empty($_GET['q'])) { |
| 18 | $_GET['q'] = drupal_get_normal_path(trim($_GET['q'], '/')); |
| 19 | } |
| 20 | else { |
| 21 | $_GET['q'] = drupal_get_normal_path(variable_get('site_frontpage', 'node')); |
| 22 | } |
| 23 | } |
| 24 | |
| 25 | /** |
| 26 | * Given an alias, return its Drupal system URL if one exists. Given a Drupal |
| 27 | * system URL return one of its aliases if such a one exists. Otherwise, |
| 28 | * return FALSE. |
| 29 | * |
| 30 | * @param $action |
| 31 | * One of the following values: |
| 32 | * - wipe: delete the alias cache. |
| 33 | * - alias: return an alias for a given Drupal system path (if one exists). |
| 34 | * - source: return the Drupal system URL for a path alias (if one exists). |
| 35 | * @param $path |
| 36 | * The path to investigate for corresponding aliases or system URLs. |
| 37 | * @param $path_language |
| 38 | * Optional language code to search the path with. Defaults to the page language. |
| 39 | * If there's no path defined for that language it will search paths without |
| 40 | * language. |
| 41 | * |
| 42 | * @return |
| 43 | * Either a Drupal system path, an aliased path, or FALSE if no path was |
| 44 | * found. |
| 45 | */ |
| 46 | function drupal_lookup_path($action, $path = '', $path_language = '') { |
| 47 | global $language; |
| 48 | $cache = &drupal_static(__FUNCTION__, array( |
| 49 | 'map' => array(), |
| 50 | 'no_src' => array(), |
| 51 | 'whitelist' => NULL, |
| 52 | 'system_paths' => array(), |
| 53 | 'no_aliases' => array(), |
| 54 | 'first_call' => TRUE, |
| 55 | )); |
| 56 | |
| 57 | // Retrieve the path alias whitelist. |
| 58 | if (!isset($cache['whitelist'])) { |
| 59 | $cache['whitelist'] = variable_get('path_alias_whitelist', NULL); |
| 60 | if (!isset($cache['whitelist'])) { |
| 61 | $cache['whitelist'] = drupal_path_alias_whitelist_rebuild(); |
| 62 | } |
| 63 | } |
| 64 | |
| 65 | $path_language = $path_language ? $path_language : $language->language; |
| 66 | |
| 67 | if ($action == 'wipe') { |
| 68 | $cache = array(); |
| 69 | $cache['whitelist'] = drupal_path_alias_whitelist_rebuild(); |
| 70 | } |
| 71 | elseif ($cache['whitelist'] && $path != '') { |
| 72 | if ($action == 'alias') { |
| 73 | // During the first call to drupal_lookup_path() per language, load the |
| 74 | // expected system paths for the page from cache. |
| 75 | if (!empty($cache['first_call'])) { |
| 76 | $cache['first_call'] = FALSE; |
| 77 | |
| 78 | $cache['map'][$path_language] = array(); |
| 79 | // Load system paths from cache. |
| 80 | $cid = current_path(); |
| 81 | if ($cached = cache_get($cid, 'cache_path')) { |
| 82 | $cache['system_paths'] = $cached->data; |
| 83 | // Now fetch the aliases corresponding to these system paths. |
| 84 | // We order by ASC and overwrite array keys to ensure the correct |
| 85 | // alias is used when there are multiple aliases per path. |
| 86 | $cache['map'][$path_language] = db_query("SELECT src, dst FROM {url_alias} WHERE src IN (:system) AND language IN (:language, '') ORDER BY language ASC, pid ASC", array( |
| 87 | ':system' => $cache['system_paths'], |
| 88 | ':language' => $path_language |
| 89 | ))->fetchAllKeyed(); |
| 90 | // Keep a record of paths with no alias to avoid querying twice. |
| 91 | $cache['no_aliases'][$path_language] = array_flip(array_diff_key($cache['system_paths'], array_keys($cache['map'][$path_language]))); |
| 92 | } |
| 93 | } |
| 94 | // If the alias has already been loaded, return it. |
| 95 | if (isset($cache['map'][$path_language][$path])) { |
| 96 | return $cache['map'][$path_language][$path]; |
| 97 | } |
| 98 | // Check the path whitelist, if the top_level part before the first / |
| 99 | // is not in the list, then there is no need to do anything further, |
| 100 | // it is not in the database. |
| 101 | elseif (!isset($cache['whitelist'][strtok($path, '/')])) { |
| 102 | return FALSE; |
| 103 | } |
| 104 | // For system paths which were not cached, query aliases individually. |
| 105 | else if (!isset($cache['no_aliases'][$path_language][$path])) { |
| 106 | // Get the most fitting result falling back with alias without language |
| 107 | $alias = db_query("SELECT dst FROM {url_alias} WHERE src = :src AND language IN (:language, '') ORDER BY language DESC, pid DESC", array( |
| 108 | ':src' => $path, |
| 109 | ':language' => $path_language |
| 110 | ))->fetchField(); |
| 111 | $cache['map'][$path_language][$path] = $alias; |
| 112 | return $alias; |
| 113 | } |
| 114 | } |
| 115 | // Check $no_src for this $path in case we've already determined that there |
| 116 | // isn't a path that has this alias |
| 117 | elseif ($action == 'source' && !isset($cache['no_src'][$path_language][$path])) { |
| 118 | // Look for the value $path within the cached $map |
| 119 | $src = ''; |
| 120 | if (!isset($cache['map'][$path_language]) || !($src = array_search($path, $cache['map'][$path_language]))) { |
| 121 | // Get the most fitting result falling back with alias without language |
| 122 | if ($src = db_query("SELECT src FROM {url_alias} WHERE dst = :dst AND language IN (:language, '') ORDER BY language DESC, pid DESC", array( |
| 123 | ':dst' => $path, |
| 124 | ':language' => $path_language)) |
| 125 | ->fetchField()) { |
| 126 | $cache['map'][$path_language][$src] = $path; |
| 127 | } |
| 128 | else { |
| 129 | // We can't record anything into $map because we do not have a valid |
| 130 | // index and there is no need because we have not learned anything |
| 131 | // about any Drupal path. Thus cache to $no_src. |
| 132 | $cache['no_src'][$path_language][$path] = TRUE; |
| 133 | } |
| 134 | } |
| 135 | return $src; |
| 136 | } |
| 137 | } |
| 138 | |
| 139 | return FALSE; |
| 140 | } |
| 141 | |
| 142 | /** |
| 143 | * Cache system paths for a page. |
| 144 | * |
| 145 | * Cache an array of the system paths available on each page. We assume |
| 146 | * that aiases will be needed for the majority of these paths during |
| 147 | * subsequent requests, and load them in a single query during |
| 148 | * drupal_lookup_path(). |
| 149 | */ |
| 150 | function drupal_cache_system_paths() { |
| 151 | // Check if the system paths for this page were loaded from cache in this |
| 152 | // request to avoid writing to cache on every request. |
| 153 | $cache = &drupal_static('drupal_lookup_path', array()); |
| 154 | if (!$cache['system_paths']) { |
| 155 | // Generate a cache ID (cid) specifically for this page. |
| 156 | $cid = current_path(); |
| 157 | // The static $map array used by drupal_lookup_path() includes all |
| 158 | // system paths for the page request. |
| 159 | if ($paths = current($cache['map'])) { |
| 160 | $data = array_keys($paths); |
| 161 | $expire = REQUEST_TIME + (60 * 60 * 24); |
| 162 | cache_set($cid, $data, 'cache_path', $expire); |
| 163 | } |
| 164 | } |
| 165 | } |
| 166 | |
| 167 | /** |
| 168 | * Given an internal Drupal path, return the alias set by the administrator. |
| 169 | * |
| 170 | * If no path is provided, the function will return the alias of the current |
| 171 | * page. |
| 172 | * |
| 173 | * @param $path |
| 174 | * An internal Drupal path. |
| 175 | * @param $path_language |
| 176 | * An optional language code to look up the path in. |
| 177 | * |
| 178 | * @return |
| 179 | * An aliased path if one was found, or the original path if no alias was |
| 180 | * found. |
| 181 | */ |
| 182 | function drupal_get_path_alias($path = NULL, $path_language = '') { |
| 183 | // If no path is specified, use the current page's path. |
| 184 | if ($path == NULL) { |
| 185 | $path = $_GET['q']; |
| 186 | } |
| 187 | $result = $path; |
| 188 | if ($alias = drupal_lookup_path('alias', $path, $path_language)) { |
| 189 | $result = $alias; |
| 190 | } |
| 191 | return $result; |
| 192 | } |
| 193 | |
| 194 | /** |
| 195 | * Given a path alias, return the internal path it represents. |
| 196 | * |
| 197 | * @param $path |
| 198 | * A Drupal path alias. |
| 199 | * @param $path_language |
| 200 | * An optional language code to look up the path in. |
| 201 | * |
| 202 | * @return |
| 203 | * The internal path represented by the alias, or the original alias if no |
| 204 | * internal path was found. |
| 205 | */ |
| 206 | function drupal_get_normal_path($path, $path_language = '') { |
| 207 | $result = $path; |
| 208 | if ($src = drupal_lookup_path('source', $path, $path_language)) { |
| 209 | $result = $src; |
| 210 | } |
| 211 | if (function_exists('custom_url_rewrite_inbound')) { |
| 212 | // Modules may alter the inbound request path by reference. |
| 213 | custom_url_rewrite_inbound($result, $path, $path_language); |
| 214 | } |
| 215 | return $result; |
| 216 | } |
| 217 | |
| 218 | /** |
| 219 | * Return a component of the current Drupal path. |
| 220 | * |
| 221 | * When viewing a page at the path "admin/structure/types", for example, arg(0) |
| 222 | * returns "admin", arg(1) returns "content", and arg(2) returns "types". |
| 223 | * |
| 224 | * Avoid use of this function where possible, as resulting code is hard to read. |
| 225 | * In menu callback functions, attempt to use named arguments. See the explanation |
| 226 | * in menu.inc for how to construct callbacks that take arguments. When attempting |
| 227 | * to use this function to load an element from the current path, e.g. loading the |
| 228 | * node on a node page, please use menu_get_object() instead. |
| 229 | * |
| 230 | * @param $index |
| 231 | * The index of the component, where each component is separated by a '/' |
| 232 | * (forward-slash), and where the first component has an index of 0 (zero). |
| 233 | * @param $path |
| 234 | * A path to break into components. Defaults to the path of the current page. |
| 235 | * |
| 236 | * @return |
| 237 | * The component specified by $index, or NULL if the specified component was |
| 238 | * not found. |
| 239 | */ |
| 240 | function arg($index = NULL, $path = NULL) { |
| 241 | $arguments = &drupal_static(__FUNCTION__); |
| 242 | |
| 243 | if (!isset($path)) { |
| 244 | $path = $_GET['q']; |
| 245 | } |
| 246 | if (!isset($arguments[$path])) { |
| 247 | $arguments[$path] = explode('/', $path); |
| 248 | } |
| 249 | if (!isset($index)) { |
| 250 | return $arguments[$path]; |
| 251 | } |
| 252 | if (isset($arguments[$path][$index])) { |
| 253 | return $arguments[$path][$index]; |
| 254 | } |
| 255 | } |
| 256 | |
| 257 | /** |
| 258 | * Get the title of the current page, for display on the page and in the title bar. |
| 259 | * |
| 260 | * @return |
| 261 | * The current page's title. |
| 262 | */ |
| 263 | function drupal_get_title() { |
| 264 | $title = drupal_set_title(); |
| 265 | |
| 266 | // During a bootstrap, menu.inc is not included and thus we cannot provide a title. |
| 267 | if (!isset($title) && function_exists('menu_get_active_title')) { |
| 268 | $title = check_plain(menu_get_active_title()); |
| 269 | } |
| 270 | |
| 271 | return $title; |
| 272 | } |
| 273 | |
| 274 | /** |
| 275 | * Set the title of the current page, for display on the page and in the title bar. |
| 276 | * |
| 277 | * @param $title |
| 278 | * Optional string value to assign to the page title; or if set to NULL |
| 279 | * (default), leaves the current title unchanged. |
| 280 | * @param $output |
| 281 | * Optional flag - normally should be left as CHECK_PLAIN. Only set to |
| 282 | * PASS_THROUGH if you have already removed any possibly dangerous code |
| 283 | * from $title using a function like check_plain() or filter_xss(). With this |
| 284 | * flag the string will be passed through unchanged. |
| 285 | * |
| 286 | * @return |
| 287 | * The updated title of the current page. |
| 288 | */ |
| 289 | function drupal_set_title($title = NULL, $output = CHECK_PLAIN) { |
| 290 | $stored_title = &drupal_static(__FUNCTION__); |
| 291 | |
| 292 | if (isset($title)) { |
| 293 | $stored_title = ($output == PASS_THROUGH) ? $title : check_plain($title); |
| 294 | } |
| 295 | |
| 296 | return $stored_title; |
| 297 | } |
| 298 | |
| 299 | /** |
| 300 | * Check if the current page is the front page. |
| 301 | * |
| 302 | * @return |
| 303 | * Boolean value: TRUE if the current page is the front page; FALSE if otherwise. |
| 304 | */ |
| 305 | function drupal_is_front_page() { |
| 306 | $is_front_page = &drupal_static(__FUNCTION__); |
| 307 | |
| 308 | if (!isset($is_front_page)) { |
| 309 | // As drupal_path_initialize updates $_GET['q'] with the 'site_frontpage' path, |
| 310 | // we can check it against the 'site_frontpage' variable. |
| 311 | $is_front_page = ($_GET['q'] == drupal_get_normal_path(variable_get('site_frontpage', 'node'))); |
| 312 | } |
| 313 | |
| 314 | return $is_front_page; |
| 315 | } |
| 316 | |
| 317 | /** |
| 318 | * Check if a path matches any pattern in a set of patterns. |
| 319 | * |
| 320 | * @param $path |
| 321 | * The path to match. |
| 322 | * @param $patterns |
| 323 | * String containing a set of patterns separated by \n, \r or \r\n. |
| 324 | * |
| 325 | * @return |
| 326 | * Boolean value: TRUE if the path matches a pattern, FALSE otherwise. |
| 327 | */ |
| 328 | function drupal_match_path($path, $patterns) { |
| 329 | $regexps = &drupal_static(__FUNCTION__); |
| 330 | |
| 331 | if (!isset($regexps[$patterns])) { |
| 332 | $regexps[$patterns] = '/^(' . preg_replace(array('/(\r\n?|\n)/', '/\\\\\*/', '/(^|\|)\\\\<front\\\\>($|\|)/'), array('|', '.*', '\1' . preg_quote(variable_get('site_frontpage', 'node'), '/') . '\2'), preg_quote($patterns, '/')) . ')$/'; |
| 333 | } |
| 334 | return (bool)preg_match($regexps[$patterns], $path); |
| 335 | } |
| 336 | |
| 337 | /** |
| 338 | * Return the current URL path of the page being viewed. |
| 339 | * |
| 340 | * Examples: |
| 341 | * - http://example.com/node/306 returns "node/306". |
| 342 | * - http://example.com/drupalfolder/node/306 returns "node/306" while |
| 343 | * base_path() returns "/drupalfolder/". |
| 344 | * - http://example.com/path/alias (which is a path alias for node/306) returns |
| 345 | * "node/306" as opposed to the path alias. |
| 346 | * |
| 347 | * This function is not available in hook_boot() so use $_GET['q'] instead. |
| 348 | * However, be careful when doing that because in the case of Example #3 |
| 349 | * $_GET['q'] will contain "path/alias". If "node/306" is needed, calling |
| 350 | * drupal_bootstrap(DRUPAL_BOOTSTRAP_PATH) makes this function available. |
| 351 | * |
| 352 | * @return |
| 353 | * The current Drupal URL path. |
| 354 | */ |
| 355 | function current_path() { |
| 356 | return $_GET['q']; |
| 357 | } |
| 358 | |
| 359 | /** |
| 360 | * Rebuild the path alias white list. |
| 361 | * |
| 362 | * @return |
| 363 | * An array containing a white list of path aliases. |
| 364 | */ |
| 365 | function drupal_path_alias_whitelist_rebuild() { |
| 366 | // For each alias in the database, get the top level component of the system |
| 367 | // path it corresponds to. This is the portion of the path before the first / |
| 368 | // if present, otherwise the whole path itself. |
| 369 | $whitelist = array(); |
| 370 | $result = db_query("SELECT SUBSTRING_INDEX(src, '/', 1) AS path FROM {url_alias} GROUP BY path"); |
| 371 | foreach ($result as $row) { |
| 372 | $whitelist[$row->path] = TRUE; |
| 373 | } |
| 374 | variable_set('path_alias_whitelist', $whitelist); |
| 375 | return $whitelist; |
| 376 | } |
| 377 |