Add new Core\Hook class

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;
+	}
+}