Add new Core\Hook class

diff --git a/src/Core/Hook.php b/src/Core/Hook.php
new file mode 100644 (file)
index 0000000..3053db7
--- /dev/null
+++ b/src/Core/Hook.php
@@ -0,0 +1,189 @@
+<?php
+/**
+ * @file src/Core/Hook.php
+ */
+namespace Friendica\Core;
+
+use Friendica\App;
+use Friendica\BaseObject;
+use Friendica\Database\DBA;
+
+require_once 'include/dba.php';
+
+/**
+ * Some functions to handle hooks
+ */
+class Hook extends BaseObject
+{
+       /**
+        * Array of registered hooks
+        *
+        * Format:
+        * [
+        *              ["<hook name>"] => [
+        *                      0 => "<hook file>",
+        *                      1 => "<hook function name>"
+        *              ],
+        *              ...
+        * ]
+        *
+        * @var array
+        */
+       private static $hooks = [];
+
+       /**
+        * Load hooks
+        */
+       public static function loadHooks()
+       {
+               self::$hooks = [];
+               $stmt = DBA::select('hook', ['hook', 'file', 'function'], [], ['order' => ['priority' => 'desc', 'file']]);
+
+               while ($hook = DBA::fetch($stmt)) {
+                       if (!array_key_exists($hook['hook'], self::$hooks)) {
+                               self::$hooks[$hook['hook']] = [];
+                       }
+                       self::$hooks[$hook['hook']][] = [$hook['file'], $hook['function']];
+               }
+               DBA::close($stmt);
+       }
+
+       /**
+        * Registers a hook.
+        *
+        * @param string $hook     the name of the hook
+        * @param string $file     the name of the file that hooks into
+        * @param string $function the name of the function that the hook will call
+        * @param int    $priority A priority (defaults to 0)
+        * @return mixed|bool
+        */
+       public static function register($hook, $file, $function, $priority = 0)
+       {
+               $file = str_replace(self::getApp()->getBasePath() . DIRECTORY_SEPARATOR, '', $file);
+
+               $condition = ['hook' => $hook, 'file' => $file, 'function' => $function];
+               if (DBA::exists('hook', $condition)) {
+                       return true;
+               }
+
+               $result = DBA::insert('hook', ['hook' => $hook, 'file' => $file, 'function' => $function, 'priority' => $priority]);
+
+               return $result;
+       }
+
+       /**
+        * Unregisters a hook.
+        *
+        * @param string $hook     the name of the hook
+        * @param string $file     the name of the file that hooks into
+        * @param string $function the name of the function that the hook called
+        * @return boolean
+        */
+       public static function unregister($hook, $file, $function)
+       {
+               $relative_file = str_replace(self::getApp()->getBasePath() . DIRECTORY_SEPARATOR, '', $file);
+
+               // This here is only needed for fixing a problem that existed on the develop branch
+               $condition = ['hook' => $hook, 'file' => $file, 'function' => $function];
+               DBA::delete('hook', $condition);
+
+               $condition = ['hook' => $hook, 'file' => $relative_file, 'function' => $function];
+               $result = DBA::delete('hook', $condition);
+               return $result;
+       }
+
+       /**
+        * Returns the list of callbacks for a single hook
+        *
+        * @param  string $name
+        * @return array
+        */
+       public static function getByName($name)
+       {
+               $return = [];
+
+               if (isset(self::$hooks[$name])) {
+                       $return = self::$hooks[$name];
+               }
+
+               return $return;
+       }
+
+       /**
+        * @brief Forks a hook.
+        *
+        * Use this function when you want to fork a hook via the worker.
+        *
+        * @param string       $name of the hook to call
+        * @param string|array $data to transmit to the callback handler
+        */
+       public static function fork($priority, $name, $data = null)
+       {
+               if (array_key_exists($name, self::$hooks)) {
+                       foreach (self::$hooks[$name] as $hook) {
+                               Worker::add($priority, 'ForkHook', $name, $hook, $data);
+                       }
+               }
+       }
+
+       /**
+        * @brief Calls a hook.
+        *
+        * Use this function when you want to be able to allow a hook to manipulate
+        * the provided data.
+        *
+        * @param string       $name  of the hook to call
+        * @param string|array &$data to transmit to the callback handler
+        */
+       public static function callAll($name, &$data = null)
+       {
+               if (array_key_exists($name, self::$hooks)) {
+                       foreach (self::$hooks[$name] as $hook) {
+                               self::callSingle(self::getApp(), $name, $hook, $data);
+                       }
+               }
+       }
+
+       /**
+        * @brief Calls a single hook.
+        *
+        * @param App $a
+        * @param string         $name of the hook to call
+        * @param array          $hook Hook data
+        * @param string|array   &$data to transmit to the callback handler
+        */
+       public static function callSingle(App $a, $name, $hook, &$data = null)
+       {
+               // Don't run a theme's hook if the user isn't using the theme
+               if (strpos($hook[0], 'view/theme/') !== false && strpos($hook[0], 'view/theme/' . $a->getCurrentTheme()) === false) {
+                       return;
+               }
+
+               @include_once($hook[0]);
+               if (function_exists($hook[1])) {
+                       $func = $hook[1];
+                       $func($a, $data);
+               } else {
+                       // remove orphan hooks
+                       $condition = ['hook' => $name, 'file' => $hook[0], 'function' => $hook[1]];
+                       DBA::delete('hook', $condition, ['cascade' => false]);
+               }
+       }
+
+       /**
+        * check if an app_menu hook exist for addon $name.
+        * Return true if the addon is an app
+        */
+       public static function isAddonApp($name)
+       {
+               if (array_key_exists('app_menu', self::$hooks)) {
+                       foreach (self::$hooks['app_menu'] as $hook) {
+                               if ($hook[0] == 'addon/' . $name . '/' . $name . '.php') {
+                                       return true;
+                               }
+                       }
+               }
+
+               return false;
+       }
+}