1 <?php

     2 // $Id: path.inc,v 1.19.2.1 2008/10/13 21:06:41 dries 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_init_path() {

    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   // $map is an array with language keys, holding arrays of Drupal paths to alias relations

    49   static $map = array(), $no_src = array(), $count;

    50 

    51   $path_language = $path_language ? $path_language : $language->language;

    52 

    53   // Use $count to avoid looking up paths in subsequent calls if there simply are no aliases

    54   if (!isset($count)) {

    55     $count = db_result(db_query('SELECT COUNT(pid) FROM {url_alias}'));

    56   }

    57 

    58   if ($action == 'wipe') {

    59     $map = array();

    60     $no_src = array();

    61     $count = NULL;

    62   }

    63   elseif ($count > 0 && $path != '') {

    64     if ($action == 'alias') {

    65       if (isset($map[$path_language][$path])) {

    66         return $map[$path_language][$path];

    67       }

    68       // Get the most fitting result falling back with alias without language

    69       $alias = db_result(db_query("SELECT dst FROM {url_alias} WHERE src = '%s' AND language IN('%s', '') ORDER BY language DESC", $path, $path_language));

    70       $map[$path_language][$path] = $alias;

    71       return $alias;

    72     }

    73     // Check $no_src for this $path in case we've already determined that there

    74     // isn't a path that has this alias

    75     elseif ($action == 'source' && !isset($no_src[$path_language][$path])) {

    76       // Look for the value $path within the cached $map

    77       $src = '';

    78       if (!isset($map[$path_language]) || !($src = array_search($path, $map[$path_language]))) {

    79         // Get the most fitting result falling back with alias without language

    80         if ($src = db_result(db_query("SELECT src FROM {url_alias} WHERE dst = '%s' AND language IN('%s', '') ORDER BY language DESC", $path, $path_language))) {

    81           $map[$path_language][$src] = $path;

    82         }

    83         else {

    84           // We can't record anything into $map because we do not have a valid

    85           // index and there is no need because we have not learned anything

    86           // about any Drupal path. Thus cache to $no_src.

    87           $no_src[$path_language][$path] = TRUE;

    88         }

    89       }

    90       return $src;

    91     }

    92   }

    93 

    94   return FALSE;

    95 }

    96 

    97 /**

    98  * Given an internal Drupal path, return the alias set by the administrator.

    99  *

   100  * @param $path

   101  *   An internal Drupal path.

   102  * @param $path_language

   103  *   An optional language code to look up the path in.

   104  *

   105  * @return

   106  *   An aliased path if one was found, or the original path if no alias was

   107  *   found.

   108  */

   109 function drupal_get_path_alias($path, $path_language = '') {

   110   $result = $path;

   111   if ($alias = drupal_lookup_path('alias', $path, $path_language)) {

   112     $result = $alias;

   113   }

   114   return $result;

   115 }

   116 

   117 /**

   118  * Given a path alias, return the internal path it represents.

   119  *

   120  * @param $path

   121  *   A Drupal path alias.

   122  * @param $path_language

   123  *   An optional language code to look up the path in.

   124  *

   125  * @return

   126  *   The internal path represented by the alias, or the original alias if no

   127  *   internal path was found.

   128  */

   129 function drupal_get_normal_path($path, $path_language = '') {

   130   $result = $path;

   131   if ($src = drupal_lookup_path('source', $path, $path_language)) {

   132     $result = $src;

   133   }

   134   if (function_exists('custom_url_rewrite_inbound')) {

   135     // Modules may alter the inbound request path by reference.

   136     custom_url_rewrite_inbound($result, $path, $path_language);

   137   }

   138   return $result;

   139 }

   140 

   141 /**

   142  * Return a component of the current Drupal path.

   143  *

   144  * When viewing a page at the path "admin/content/types", for example, arg(0)

   145  * would return "admin", arg(1) would return "content", and arg(2) would return

   146  * "types".

   147  *

   148  * Avoid use of this function where possible, as resulting code is hard to read.

   149  * Instead, attempt to use named arguments in menu callback functions. See the

   150  * explanation in menu.inc for how to construct callbacks that take arguments.

   151  *

   152  * @param $index

   153  *   The index of the component, where each component is separated by a '/'

   154  *   (forward-slash), and where the first component has an index of 0 (zero).

   155  *

   156  * @return

   157  *   The component specified by $index, or NULL if the specified component was

   158  *   not found.

   159  */

   160 function arg($index = NULL, $path = NULL) {

   161   static $arguments;

   162 

   163   if (!isset($path)) {

   164     $path = $_GET['q'];

   165   }

   166   if (!isset($arguments[$path])) {

   167     $arguments[$path] = explode('/', $path);

   168   }

   169   if (!isset($index)) {

   170     return $arguments[$path];

   171   }

   172   if (isset($arguments[$path][$index])) {

   173     return $arguments[$path][$index];

   174   }

   175 }

   176 

   177 /**

   178  * Get the title of the current page, for display on the page and in the title bar.

   179  *

   180  * @return

   181  *   The current page's title.

   182  */

   183 function drupal_get_title() {

   184   $title = drupal_set_title();

   185 

   186   // during a bootstrap, menu.inc is not included and thus we cannot provide a title

   187   if (!isset($title) && function_exists('menu_get_active_title')) {

   188     $title = check_plain(menu_get_active_title());

   189   }

   190 

   191   return $title;

   192 }

   193 

   194 /**

   195  * Set the title of the current page, for display on the page and in the title bar.

   196  *

   197  * @param $title

   198  *   Optional string value to assign to the page title; or if set to NULL

   199  *   (default), leaves the current title unchanged.

   200  *

   201  * @return

   202  *   The updated title of the current page.

   203  */

   204 function drupal_set_title($title = NULL) {

   205   static $stored_title;

   206 

   207   if (isset($title)) {

   208     $stored_title = $title;

   209   }

   210   return $stored_title;

   211 }

   212 

   213 /**

   214  * Check if the current page is the front page.

   215  *

   216  * @return

   217  *   Boolean value: TRUE if the current page is the front page; FALSE if otherwise.

   218  */

   219 function drupal_is_front_page() {

   220   // As drupal_init_path updates $_GET['q'] with the 'site_frontpage' path,

   221   // we can check it against the 'site_frontpage' variable.

   222   return $_GET['q'] == drupal_get_normal_path(variable_get('site_frontpage', 'node'));

   223 }

   224 

   225 /**

   226  * Check if a path matches any pattern in a set of patterns.

   227  *

   228  * @param $path

   229  *   The path to match.

   230  * @param $patterns

   231  *   String containing a set of patterns separated by \n, \r or \r\n.

   232  *

   233  * @return

   234  *   Boolean value: TRUE if the path matches a pattern, FALSE otherwise.

   235  */

   236 function drupal_match_path($path, $patterns) {

   237   static $regexps;

   238 

   239   if (!isset($regexps[$patterns])) {

   240     $regexps[$patterns] = '/^('. preg_replace(array('/(\r\n?|\n)/', '/\\\\\*/', '/(^|\|)\\\\<front\\\\>($|\|)/'), array('|', '.*', '\1'. preg_quote(variable_get('site_frontpage', 'node'), '/') .'\2'), preg_quote($patterns, '/')) .')$/';

   241   }

   242   return preg_match($regexps[$patterns], $path);

   243 }