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 string $hook
  52          * @param string $file
  53          * @param string $function
  54          */
  55         public static function add($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    $priority A priority (defaults to 0)
  72          * @return mixed|bool
  73          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
  74          */
  75         public static function register($hook, $file, $function, $priority = 0)
  76         {
  77                 $file = str_replace(self::getApp()->getBasePath() . DIRECTORY_SEPARATOR, '', $file);
  78
  79                 $condition = ['hook' => $hook, 'file' => $file, 'function' => $function];
  80                 if (DBA::exists('hook', $condition)) {
  81                         return true;
  82                 }
  83
  84                 $result = DBA::insert('hook', ['hook' => $hook, 'file' => $file, 'function' => $function, 'priority' => $priority]);
  85
  86                 return $result;
  87         }
  88
  89         /**
  90          * Unregisters a hook.
  91          *
  92          * @param string $hook     the name of the hook
  93          * @param string $file     the name of the file that hooks into
  94          * @param string $function the name of the function that the hook called
  95          * @return boolean
  96          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
  97          */
  98         public static function unregister($hook, $file, $function)
  99         {
 100                 $relative_file = str_replace(self::getApp()->getBasePath() . DIRECTORY_SEPARATOR, '', $file);
 101
 102                 // This here is only needed for fixing a problem that existed on the develop branch
 103                 $condition = ['hook' => $hook, 'file' => $file, 'function' => $function];
 104                 DBA::delete('hook', $condition);
 105
 106                 $condition = ['hook' => $hook, 'file' => $relative_file, 'function' => $function];
 107                 $result = DBA::delete('hook', $condition);
 108                 return $result;
 109         }
 110
 111         /**
 112          * Returns the list of callbacks for a single hook
 113          *
 114          * @param  string $name Name of the hook
 115          * @return array
 116          */
 117         public static function getByName($name)
 118         {
 119                 $return = [];
 120
 121                 if (isset(self::$hooks[$name])) {
 122                         $return = self::$hooks[$name];
 123                 }
 124
 125                 return $return;
 126         }
 127
 128         /**
 129          * @brief Forks a hook.
 130          *
 131          * Use this function when you want to fork a hook via the worker.
 132          *
 133          * @param integer $priority of the hook
 134          * @param string  $name     of the hook to call
 135          * @param mixed   $data     to transmit to the callback handler
 136          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 137          */
 138         public static function fork($priority, $name, $data = null)
 139         {
 140                 if (array_key_exists($name, self::$hooks)) {
 141                         foreach (self::$hooks[$name] as $hook) {
 142                                 // Call a hook to check if this hook call needs to be forked
 143                                 if (array_key_exists('hook_fork', self::$hooks)) {
 144                                         $hookdata = ['name' => $name, 'data' => $data, 'execute' => true];
 145
 146                                         foreach (self::$hooks['hook_fork'] as $fork_hook) {
 147                                                 if ($hook[0] != $fork_hook[0]) {
 148                                                         continue;
 149                                                 }
 150                                                 self::callSingle(self::getApp(), 'hook_fork', $fork_hook, $hookdata);
 151                                         }
 152
 153                                         if (!$hookdata['execute']) {
 154                                                 continue;
 155                                         }
 156                                 }
 157
 158                                 Worker::add($priority, 'ForkHook', $name, $hook, $data);
 159                         }
 160                 }
 161         }
 162
 163         /**
 164          * @brief Calls a hook.
 165          *
 166          * Use this function when you want to be able to allow a hook to manipulate
 167          * the provided data.
 168          *
 169          * @param string        $name of the hook to call
 170          * @param string|array &$data to transmit to the callback handler
 171          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 172          */
 173         public static function callAll($name, &$data = null)
 174         {
 175                 if (array_key_exists($name, self::$hooks)) {
 176                         foreach (self::$hooks[$name] as $hook) {
 177                                 self::callSingle(self::getApp(), $name, $hook, $data);
 178                         }
 179                 }
 180         }
 181
 182         /**
 183          * @brief Calls a single hook.
 184          *
 185          * @param App             $a
 186          * @param string          $name of the hook to call
 187          * @param array           $hook Hook data
 188          * @param string|array   &$data to transmit to the callback handler
 189          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 190          */
 191         public static function callSingle(App $a, $name, $hook, &$data = null)
 192         {
 193                 // Don't run a theme's hook if the user isn't using the theme
 194                 if (strpos($hook[0], 'view/theme/') !== false && strpos($hook[0], 'view/theme/' . $a->getCurrentTheme()) === false) {
 195                         return;
 196                 }
 197
 198                 @include_once($hook[0]);
 199                 if (function_exists($hook[1])) {
 200                         $func = $hook[1];
 201                         $func($a, $data);
 202                 } else {
 203                         // remove orphan hooks
 204                         $condition = ['hook' => $name, 'file' => $hook[0], 'function' => $hook[1]];
 205                         DBA::delete('hook', $condition, ['cascade' => false]);
 206                 }
 207         }
 208
 209         /**
 210          * Checks if an app_menu hook exist for the provided addon name.
 211          * Return true if the addon is an app
 212          *
 213          * @param string $name Name of the addon
 214          * @return boolean
 215          */
 216         public static function isAddonApp($name)
 217         {
 218                 if (array_key_exists('app_menu', self::$hooks)) {
 219                         foreach (self::$hooks['app_menu'] as $hook) {
 220                                 if ($hook[0] == 'addon/' . $name . '/' . $name . '.php') {
 221                                         return true;
 222                                 }
 223                         }
 224                 }
 225
 226                 return false;
 227         }
 228 }