Plugin hooks

git-svn-id: https://code.elgg.org/elgg/trunk@276 36083f99-b078-4883-b0ff-0f9b5a30f544

1 files changed, 81 insertions, 15 deletions

diff --git a/engine/lib/elgglib.php b/engine/lib/elgglib.php
index 69ea20138..63de9d1b5 100644
--- a/engine/lib/elgglib.php
+++ b/engine/lib/elgglib.php
@@ -306,7 +306,6 @@
 	 * @param array $children_array Optionally, an array of children

 	 * @return false|stdClass Depending on success

 	 */

-		

 		function make_register_object($register_name, $register_value, $children_array = array()) {

 			

 			if (empty($register_name) || empty($subregister_name) || empty($register_array))

@@ -534,14 +533,14 @@
 		

 		function events($event = "", $object_type = "", $function = "", $priority = 500, $call = false, $object = null) {

 			

-			static $events;

+			global $CONFIG;

 			

-			if (!isset($events)) {

-				$events = array();

-			} else if (!isset($events[$event]) && !empty($event)) {

-				$events[$event] = array();

-			} else if (!isset($events[$event][$object_type]) && !empty($event) && !empty($object_type)) {

-				$events[$event][$object_type] = array();

+			if (!isset($CONFIG->events)) {

+				$CONFIG->events = array();

+			} else if (!isset($CONFIG->events[$event]) && !empty($event)) {

+				$CONFIG->events[$event] = array();

+			} else if (!isset($CONFIG->events[$event][$object_type]) && !empty($event) && !empty($object_type)) {

+				$CONFIG->events[$event][$object_type] = array();

 			}

 			

 			if (!$call) {

@@ -549,11 +548,11 @@
 				if (!empty($event) && !empty($object_type) && is_callable($function)) {

 					$priority = (int) $priority;

 					if ($priority < 0) $priority = 0;

-					while (isset($events[$event][$object_type][$priority])) {

+					while (isset($CONFIG->events[$event][$object_type][$priority])) {

 						$priority++;

 					}

-					$events[$event][$object_type][$priority] = $function;

-					ksort($events[$event][$object_type]);

+					$CONFIG->events[$event][$object_type][$priority] = $function;

+					ksort($CONFIG->events[$event][$object_type]);

 					return true;

 				} else {

 					return false;

@@ -561,8 +560,8 @@
 			

 			} else {

 			

-				if (!empty($events[$event][$object_type]) && is_array($events[$event][$object_type])) {

-					foreach($events[$event][$object_type] as $eventfunction) {

+				if (!empty($CONFIG->events[$event][$object_type]) && is_array($CONFIG->events[$event][$object_type])) {

+					foreach($CONFIG->events[$event][$object_type] as $eventfunction) {

 						if ($eventfunction($event, $object_type, $object) === false) {

 							return false;

 						}

@@ -583,8 +582,7 @@
 	 * @param string $object_type The object type

 	 * @param string $function The function name

 	 * @return true|false Depending on success 

-	 */

-		

+	 */	

 		function register_event_handler($event, $object_type, $function, $priority = 500) {

 			return events($event, $object_type, $function, $priority);

 		}

@@ -608,6 +606,74 @@
 		}

 		

 	/**

+	 * Register a function to a plugin hook for a particular entity type, with a given priority.

+	 * 

+	 * eg if you want the function "export_user" to be called when the hook "export" for "user" entities 

+	 * is run, use:

+	 * 

+	 * 		register_plugin_hook("export", "user", "export_user");

+	 * 

+	 * "all" is a valid value for both $hook and $entity_type. "none" is a valid value for $entity_type.

+	 *

+	 * @param string $hook The name of the hook

+	 * @param string $entity_type The name of the type of entity (eg "user", "object" etc)

+	 * @param string $function The name of a valid function to be run

+	 * @param string $priority The priority - 0 is first, 1000 last, default is 500

+	 * @return true|false Depending on success

+	 */

+		function register_plugin_hook($hook, $entity_type, $function, $priority = 500) {

+			global $CONFIG;

+			

+			if (!isset($CONFIG->hooks)) {

+				$CONFIG->hooks = array();

+			} else if (!isset($CONFIG->hooks[$hook]) && !empty($hook)) {

+				$CONFIG->hooks[$hook] = array();

+			}

+			

+			if (!empty($hook) && is_callable($function)) {

+				$priority = (int) $priority;

+				if ($priority < 0) $priority = 0;

+				while (isset($CONFIG->hooks[$hook][$priority])) {

+					$priority++;

+				}

+				$CONFIG->hooks[$hook][$priority] = $function;

+				ksort($CONFIG->hooks[$hook]);

+				return true;

+			} else {

+				return false;

+			}

+			

+		}

+		

+	/**

+	 * Triggers a plugin hook, with various parameters as an array. For example, if you're 

+	 *

+	 * @param string $hook The name of the hook to trigger

+	 * @param string $entity_type The name of the entity type to trigger it for (or "all", or "none")

+	 * @param array $params Any parameters. It's good practice to name the keys, i.e. by using array('name' => 'value', 'name2' => 'value2')

+	 * @return mixed|null The cumulative return value for the plugin hook functions

+	 */

+		function trigger_plugin_hook($hook, $entity_type, $params = null) {

+			global $CONFIG;

+			

+			$returnvalue = null;

+			

+			if (!empty($CONFIG->hooks[$hook][$entity_type]) && is_array($CONFIG->hooks[$hook][$entity_type])) {

+				foreach($CONFIG->hooks[$hook][$entity_type] as $hookfunction) {

+					$temp_return_value = $hookfunction($hook, $entity_type, $returnvalue, $params);

+					if (!is_null($temp_return_value)) $returnvalue = $temp_return_value;

+				}

+			}

+			if (!empty($CONFIG->hooks['all'][$entity_type]) && is_array($CONFIG->hooks['all'][$entity_type])) {

+				foreach($CONFIG->hooks['all'][$entity_type] as $hookfunction) {

+					$temp_return_value = $hookfunction('all', $entity_type, $returnvalue, $params);

+					if (!is_null($temp_return_value)) $returnvalue = $temp_return_value;

+				}

+			}

+			return $returnvalue;

+		}

+		

+	/**

 	 * Error handling

 	 */