1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
|
<?php
/**
* StatusNet, the distributed open-source microblogging tool
*
* utilities for defining and running event handlers
*
* PHP version 5
*
* LICENCE: This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* @category Event
* @package StatusNet
* @author Evan Prodromou <evan@status.net>
* @copyright 2008 StatusNet, Inc.
* @license http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
* @link http://status.net/
*/
if (!defined('STATUSNET') && !defined('LACONICA')) {
exit(1);
}
/**
* Class for events
*
* This "class" two static functions for managing events in the StatusNet code.
*
* @category Event
* @package StatusNet
* @author Evan Prodromou <evan@status.net>
* @license http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
* @link http://status.net/
*
* @todo Define a system for using Event instances
*/
class Event {
/* Global array of hooks, mapping eventname => array of callables */
protected static $_handlers = array();
/**
* Add an event handler
*
* To run some code at a particular point in StatusNet processing.
* Named events include receiving an XMPP message, adding a new notice,
* or showing part of an HTML page.
*
* The arguments to the handler vary by the event. Handlers can return
* two possible values: false means that the event has been replaced by
* the handler completely, and no default processing should be done.
* Non-false means successful handling, and that the default processing
* should succeed. (Note that this only makes sense for some events.)
*
* Handlers can also abort processing by throwing an exception; these will
* be caught by the closest code and displayed as errors.
*
* @param string $name Name of the event
* @param callable $handler Code to run
*
* @return void
*/
public static function addHandler($name, $handler) {
if (array_key_exists($name, Event::$_handlers)) {
Event::$_handlers[$name][] = $handler;
} else {
Event::$_handlers[$name] = array($handler);
}
}
/**
* Handle an event
*
* Events are any point in the code that we want to expose for admins
* or third-party developers to use.
*
* We pass in an array of arguments (including references, for stuff
* that can be changed), and each assigned handler gets run with those
* arguments. Exceptions can be thrown to indicate an error.
*
* @param string $name Name of the event that's happening
* @param array $args Arguments for handlers
*
* @return boolean flag saying whether to continue processing, based
* on results of handlers.
*/
public static function handle($name, $args=array()) {
$result = null;
if (array_key_exists($name, Event::$_handlers)) {
foreach (Event::$_handlers[$name] as $handler) {
$result = call_user_func_array($handler, $args);
if ($result === false) {
break;
}
}
}
return ($result !== false);
}
/**
* Check to see if an event handler exists
*
* Look to see if there's any handler for a given event, or narrow
* by providing the name of a specific plugin class.
*
* @param string $name Name of the event to look for
* @param string $plugin Optional name of the plugin class to look for
*
* @return boolean flag saying whether such a handler exists
*
*/
public static function hasHandler($name, $plugin=null) {
if (array_key_exists($name, Event::$_handlers)) {
if (isset($plugin)) {
foreach (Event::$_handlers[$name] as $handler) {
if (get_class($handler[0]) == $plugin) {
return true;
}
}
} else {
return true;
}
}
return false;
}
/**
* Disables any and all handlers that have been set up so far;
* use only if you know it's safe to reinitialize all plugins.
*/
public static function clearHandlers() {
Event::$_handlers = array();
}
}
|
