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authorsembrestels <sembrestels@riseup.net>2011-10-13 15:23:11 +0200
committersembrestels <sembrestels@riseup.net>2011-10-13 15:23:11 +0200
commit74bd6999c5e5c23ebbf90dbb6bdaabbddd7594cf (patch)
tree834c120d692be288f261bcae169eedd3d6b31d74 /vendors/dokuwiki/inc/events.php
parentf8be8643f0faadb2c0ce87d553b7b9d569af5afd (diff)
downloadelgg-74bd6999c5e5c23ebbf90dbb6bdaabbddd7594cf.tar.gz
elgg-74bd6999c5e5c23ebbf90dbb6bdaabbddd7594cf.tar.bz2
Rename lib/dokuwiki to vendors/dokuwiki
Diffstat (limited to 'vendors/dokuwiki/inc/events.php')
-rw-r--r--vendors/dokuwiki/inc/events.php202
1 files changed, 202 insertions, 0 deletions
diff --git a/vendors/dokuwiki/inc/events.php b/vendors/dokuwiki/inc/events.php
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+++ b/vendors/dokuwiki/inc/events.php
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+<?php
+/**
+ * DokuWiki Events
+ *
+ * @license GPL 2 (http://www.gnu.org/licenses/gpl.html)
+ * @author Christopher Smith <chris@jalakai.co.uk>
+ */
+
+if(!defined('DOKU_INC')) die('meh.');
+require_once(DOKU_INC.'inc/pluginutils.php');
+
+class Doku_Event {
+
+ // public properties
+ var $name = ''; // READONLY event name, objects must register against this name to see the event
+ var $data = NULL; // READWRITE data relevant to the event, no standardised format (YET!)
+ var $result = NULL; // READWRITE the results of the event action, only relevant in "_AFTER" advise
+ // event handlers may modify this if they are preventing the default action
+ // to provide the after event handlers with event results
+ var $canPreventDefault = true; // READONLY if true, event handlers can prevent the events default action
+
+ // private properties, event handlers can effect these through the provided methods
+ var $_default = true; // whether or not to carry out the default action associated with the event
+ var $_continue = true; // whether or not to continue propagating the event to other handlers
+
+ /**
+ * event constructor
+ */
+ function Doku_Event($name, &$data) {
+
+ $this->name = $name;
+ $this->data =& $data;
+
+ }
+
+ /**
+ * advise functions
+ *
+ * advise all registered handlers of this event
+ *
+ * if these methods are used by functions outside of this object, they must
+ * properly handle correct processing of any default action and issue an
+ * advise_after() signal. e.g.
+ * $evt = new Doku_Event(name, data);
+ * if ($evt->advise_before(canPreventDefault) {
+ * // default action code block
+ * }
+ * $evt->advise_after();
+ * unset($evt);
+ *
+ * @return results of processing the event, usually $this->_default
+ */
+ function advise_before($enablePreventDefault=true) {
+ global $EVENT_HANDLER;
+
+ $this->canPreventDefault = $enablePreventDefault;
+ $EVENT_HANDLER->process_event($this,'BEFORE');
+
+ return (!$enablePreventDefault || $this->_default);
+ }
+
+ function advise_after() {
+ global $EVENT_HANDLER;
+
+ $this->_continue = true;
+ $EVENT_HANDLER->process_event($this,'AFTER');
+ }
+
+ /**
+ * trigger
+ *
+ * - advise all registered (<event>_BEFORE) handlers that this event is about to take place
+ * - carry out the default action using $this->data based on $enablePrevent and
+ * $this->_default, all of which may have been modified by the event handlers.
+ * - advise all registered (<event>_AFTER) handlers that the event has taken place
+ *
+ * @return $event->results
+ * the value set by any <event>_before or <event> handlers if the default action is prevented
+ * or the results of the default action (as modified by <event>_after handlers)
+ * or NULL no action took place and no handler modified the value
+ */
+ function trigger($action=NULL, $enablePrevent=true) {
+
+ if (!is_callable($action)) $enablePrevent = false;
+
+ if ($this->advise_before($enablePrevent) && is_callable($action)) {
+ if (is_array($action)) {
+ list($obj,$method) = $action;
+ $this->result = $obj->$method($this->data);
+ } else {
+ $this->result = $action($this->data);
+ }
+ }
+
+ $this->advise_after();
+
+ return $this->result;
+ }
+
+ /**
+ * stopPropagation
+ *
+ * stop any further processing of the event by event handlers
+ * this function does not prevent the default action taking place
+ */
+ function stopPropagation() { $this->_continue = false; }
+
+ /**
+ * preventDefault
+ *
+ * prevent the default action taking place
+ */
+ function preventDefault() { $this->_default = false; }
+}
+
+class Doku_Event_Handler {
+
+ // public properties: none
+
+ // private properties
+ var $_hooks = array(); // array of events and their registered handlers
+
+ /**
+ * event_handler
+ *
+ * constructor, loads all action plugins and calls their register() method giving them
+ * an opportunity to register any hooks they require
+ */
+ function Doku_Event_Handler() {
+
+ // load action plugins
+ $plugin = NULL;
+ $pluginlist = plugin_list('action');
+
+ foreach ($pluginlist as $plugin_name) {
+ $plugin =& plugin_load('action',$plugin_name);
+
+ if ($plugin !== NULL) $plugin->register($this);
+ }
+ }
+
+ /**
+ * register_hook
+ *
+ * register a hook for an event
+ *
+ * @PARAM $event (string) name used by the event, (incl '_before' or '_after' for triggers)
+ * @PARAM $obj (obj) object in whose scope method is to be executed,
+ * if NULL, method is assumed to be a globally available function
+ * @PARAM $method (function) event handler function
+ * @PARAM $param (mixed) data passed to the event handler
+ */
+ function register_hook($event, $advise, &$obj, $method, $param=NULL) {
+ $this->_hooks[$event.'_'.$advise][] = array(&$obj, $method, $param);
+ }
+
+ function process_event(&$event,$advise='') {
+
+ $evt_name = $event->name . ($advise ? '_'.$advise : '_BEFORE');
+
+ if (!empty($this->_hooks[$evt_name])) {
+ $hook = reset($this->_hooks[$evt_name]);
+ do {
+// list($obj, $method, $param) = $hook;
+ $obj =& $hook[0];
+ $method = $hook[1];
+ $param = $hook[2];
+
+ if (is_null($obj)) {
+ $method($event, $param);
+ } else {
+ $obj->$method($event, $param);
+ }
+
+ } while ($event->_continue && $hook = next($this->_hooks[$evt_name]));
+ }
+ }
+}
+
+/**
+ * trigger_event
+ *
+ * function wrapper to process (create, trigger and destroy) an event
+ *
+ * @PARAM $name (string) name for the event
+ * @PARAM $data (mixed) event data
+ * @PARAM $action (callback) (optional, default=NULL) default action, a php callback function
+ * @PARAM $canPreventDefault (bool) (optional, default=true) can hooks prevent the default action
+ *
+ * @RETURN (mixed) the event results value after all event processing is complete
+ * by default this is the return value of the default action however
+ * it can be set or modified by event handler hooks
+ */
+function trigger_event($name, &$data, $action=NULL, $canPreventDefault=true) {
+
+ $evt = new Doku_Event($name, $data);
+ return $evt->trigger($action, $canPreventDefault);
+}
+
+// create the event handler
+global $EVENT_HANDLER;
+$EVENT_HANDLER = new Doku_Event_Handler();