src/Core/Hook.php

   1 <?php
   2 /**
   3  * @file src/Core/Hook.php
   4  */
   5 namespace Friendica\Core;
   6
   7 use Friendica\App;
   8 use Friendica\BaseObject;
   9 use Friendica\Database\DBA;
  10
  11 /**
  12  * Some functions to handle hooks
  13  */
  14 class Hook extends BaseObject
  15 {
  16         /**
  17          * Array of registered hooks
  18          *
  19          * Format:
  20          * [
  21          *              ["<hook name>"] => [
  22          *                      0 => "<hook file>",
  23          *                      1 => "<hook function name>"
  24          *              ],
  25          *              ...
  26          * ]
  27          *
  28          * @var array
  29          */
  30         private static $hooks = [];
  31
  32         /**
  33          * Load hooks
  34          */
  35         public static function loadHooks()
  36         {
  37                 self::$hooks = [];
  38                 $stmt = DBA::select('hook', ['hook', 'file', 'function'], [], ['order' => ['priority' => 'desc', 'file']]);
  39
  40                 while ($hook = DBA::fetch($stmt)) {
  41                         self::add($hook['hook'], $hook['file'], $hook['function']);
  42                 }
  43                 DBA::close($stmt);
  44         }
  45
  46         /**
  47          * @brief Adds a new hook to the hooks array.
  48          *
  49          * This function is meant to be called by modules on each page load as it works after loadHooks has been called.
  50          *
  51          * @param type $hook
  52          * @param type $file
  53          * @param type $function
  54          */
  55         public static function add($hook, $file, $function)
  56         {
  57                 if (!array_key_exists($hook, self::$hooks)) {
  58                         self::$hooks[$hook] = [];
  59                 }
  60                 self::$hooks[$hook][] = [$file, $function];
  61         }
  62
  63         /**
  64          * @brief Registers a hook.
  65          *
  66          * This function is meant to be called once when an addon is enabled for example as it doesn't add to the current hooks.
  67          *
  68          * @param string $hook     the name of the hook
  69          * @param string $file     the name of the file that hooks into
  70          * @param string $function the name of the function that the hook will call
  71          * @param int    $priority A priority (defaults to 0)
  72          * @return mixed|bool
  73          */
  74         public static function register($hook, $file, $function, $priority = 0)
  75         {
  76                 $file = str_replace(self::getApp()->getBasePath() . DIRECTORY_SEPARATOR, '', $file);
  77
  78                 $condition = ['hook' => $hook, 'file' => $file, 'function' => $function];
  79                 if (DBA::exists('hook', $condition)) {
  80                         return true;
  81                 }
  82
  83                 $result = DBA::insert('hook', ['hook' => $hook, 'file' => $file, 'function' => $function, 'priority' => $priority]);
  84
  85                 return $result;
  86         }
  87
  88         /**
  89          * Unregisters a hook.
  90          *
  91          * @param string $hook     the name of the hook
  92          * @param string $file     the name of the file that hooks into
  93          * @param string $function the name of the function that the hook called
  94          * @return boolean
  95          */
  96         public static function unregister($hook, $file, $function)
  97         {
  98                 $relative_file = str_replace(self::getApp()->getBasePath() . DIRECTORY_SEPARATOR, '', $file);
  99
 100                 // This here is only needed for fixing a problem that existed on the develop branch
 101                 $condition = ['hook' => $hook, 'file' => $file, 'function' => $function];
 102                 DBA::delete('hook', $condition);
 103
 104                 $condition = ['hook' => $hook, 'file' => $relative_file, 'function' => $function];
 105                 $result = DBA::delete('hook', $condition);
 106                 return $result;
 107         }
 108
 109         /**
 110          * Returns the list of callbacks for a single hook
 111          *
 112          * @param  string $name Name of the hook
 113          * @return array
 114          */
 115         public static function getByName($name)
 116         {
 117                 $return = [];
 118
 119                 if (isset(self::$hooks[$name])) {
 120                         $return = self::$hooks[$name];
 121                 }
 122
 123                 return $return;
 124         }
 125
 126         /**
 127          * @brief Forks a hook.
 128          *
 129          * Use this function when you want to fork a hook via the worker.
 130          *
 131          * @param integer $priority of the hook
 132          * @param string  $name     of the hook to call
 133          * @param mixed   $data     to transmit to the callback handler
 134          */
 135         public static function fork($priority, $name, $data = null)
 136         {
 137                 if (array_key_exists($name, self::$hooks)) {
 138                         foreach (self::$hooks[$name] as $hook) {
 139                                 // Call a hook to check if this hook call needs to be forked
 140                                 if (array_key_exists('hook_fork', self::$hooks)) {
 141                                         $hookdata = ['name' => $name, 'data' => $data, 'execute' => true];
 142
 143                                         foreach (self::$hooks['hook_fork'] as $fork_hook) {
 144                                                 if ($hook[0] != $fork_hook[0]) {
 145                                                         continue;
 146                                                 }
 147                                                 self::callSingle(self::getApp(), 'hook_fork', $fork_hook, $hookdata);
 148                                         }
 149
 150                                         if (!$hookdata['execute']) {
 151                                                 continue;
 152                                         }
 153                                 }
 154
 155                                 Worker::add($priority, 'ForkHook', $name, $hook, $data);
 156                         }
 157                 }
 158         }
 159
 160         /**
 161          * @brief Calls a hook.
 162          *
 163          * Use this function when you want to be able to allow a hook to manipulate
 164          * the provided data.
 165          *
 166          * @param string       $name  of the hook to call
 167          * @param string|array &$data to transmit to the callback handler
 168          */
 169         public static function callAll($name, &$data = null)
 170         {
 171                 if (array_key_exists($name, self::$hooks)) {
 172                         foreach (self::$hooks[$name] as $hook) {
 173                                 self::callSingle(self::getApp(), $name, $hook, $data);
 174                         }
 175                 }
 176         }
 177
 178         /**
 179          * @brief Calls a single hook.
 180          *
 181          * @param App $a
 182          * @param string         $name of the hook to call
 183          * @param array          $hook Hook data
 184          * @param string|array   &$data to transmit to the callback handler
 185          */
 186         public static function callSingle(App $a, $name, $hook, &$data = null)
 187         {
 188                 // Don't run a theme's hook if the user isn't using the theme
 189                 if (strpos($hook[0], 'view/theme/') !== false && strpos($hook[0], 'view/theme/' . $a->getCurrentTheme()) === false) {
 190                         return;
 191                 }
 192
 193                 @include_once($hook[0]);
 194                 if (function_exists($hook[1])) {
 195                         $func = $hook[1];
 196                         $func($a, $data);
 197                 } else {
 198                         // remove orphan hooks
 199                         $condition = ['hook' => $name, 'file' => $hook[0], 'function' => $hook[1]];
 200                         DBA::delete('hook', $condition, ['cascade' => false]);
 201                 }
 202         }
 203
 204         /**
 205          * Checks if an app_menu hook exist for the provided addon name.
 206          * Return true if the addon is an app
 207          *
 208          * @param string $name Name of the addon
 209          * @return boolean
 210          */
 211         public static function isAddonApp($name)
 212         {
 213                 if (array_key_exists('app_menu', self::$hooks)) {
 214                         foreach (self::$hooks['app_menu'] as $hook) {
 215                                 if ($hook[0] == 'addon/' . $name . '/' . $name . '.php') {
 216                                         return true;
 217                                 }
 218                         }
 219                 }
 220
 221                 return false;
 222         }
 223 }