1 | <?php |
---|
2 | /** |
---|
3 | * Implements the Observer design pattern defining Observable |
---|
4 | * objects, when a class extends Observable Observers can be attached to |
---|
5 | * the class listening for some event. When an event is detected in any |
---|
6 | * method of the derived class the method can call notifyAll($event,$msg) |
---|
7 | * to notify all the observers listening for event $event. |
---|
8 | * The Observer objects must extend the Observer class and define the |
---|
9 | * notify($event,$msg) method |
---|
10 | * |
---|
11 | * @abstract |
---|
12 | * @package Galaxia |
---|
13 | * @license http://www.gnu.org/copyleft/gpl.html GPL |
---|
14 | */ |
---|
15 | class Observable { |
---|
16 | /** |
---|
17 | * @var array $_observers Observed subclasses |
---|
18 | * @access private |
---|
19 | */ |
---|
20 | var $_observers=Array(); |
---|
21 | |
---|
22 | /** |
---|
23 | * Empty constructor |
---|
24 | * |
---|
25 | * @access public |
---|
26 | * @return object Observable instance |
---|
27 | */ |
---|
28 | function Observable() { |
---|
29 | |
---|
30 | } |
---|
31 | |
---|
32 | /** |
---|
33 | * This method can be used to attach an object to the class listening for |
---|
34 | * some specific event. The object will be notified when the specified |
---|
35 | * event is triggered by the derived class |
---|
36 | * |
---|
37 | * @param string $event |
---|
38 | * @param object &$obj |
---|
39 | * @access public |
---|
40 | * @return mixed |
---|
41 | */ |
---|
42 | function attach($event, &$obj) |
---|
43 | { |
---|
44 | if (!is_object($obj)) { |
---|
45 | return false; |
---|
46 | } |
---|
47 | $obj->_observerId = uniqid(rand()); |
---|
48 | $this->_observers[$event][$obj->_observerId] = &$obj; |
---|
49 | } |
---|
50 | |
---|
51 | /** |
---|
52 | * Attaches an object to the class listening for any event, |
---|
53 | * The object will be notified when any event occurs in the derived class |
---|
54 | * |
---|
55 | * @param object &$obj |
---|
56 | * @return mixed |
---|
57 | * @access public |
---|
58 | */ |
---|
59 | function attach_all(&$obj) |
---|
60 | { |
---|
61 | if (!is_object($obj)) { |
---|
62 | return false; |
---|
63 | } |
---|
64 | $obj->_observerId = uniqid(rand()); |
---|
65 | $this->_observers['all'][$obj->_observerId] = &$obj; |
---|
66 | } |
---|
67 | |
---|
68 | /** |
---|
69 | * Detaches an observer from the class |
---|
70 | * |
---|
71 | * @param object &$obj |
---|
72 | * @return void |
---|
73 | * @access public |
---|
74 | */ |
---|
75 | function dettach(&$obj) |
---|
76 | { |
---|
77 | if (isset($this->_observers[$obj->_observerId])) { |
---|
78 | unset($this->_observers[$obj->_observerId]); |
---|
79 | } |
---|
80 | } |
---|
81 | |
---|
82 | /** |
---|
83 | * Notifies objects of an event. This is called in the methods of the derived class that want to notify some event |
---|
84 | * |
---|
85 | * @access protected |
---|
86 | * @param string $event |
---|
87 | * @param string $msg |
---|
88 | * @return void |
---|
89 | */ |
---|
90 | function notify_all($event, $msg) |
---|
91 | { |
---|
92 | //reset($this->_observers[$event]); |
---|
93 | if(isset($this->_observers[$event])) { |
---|
94 | foreach ($this->_observers[$event] as $observer) { |
---|
95 | $observer->notify($event,$msg); |
---|
96 | } |
---|
97 | } |
---|
98 | if(isset($this->_observers['all'])) { |
---|
99 | foreach ($this->_observers['all'] as $observer) { |
---|
100 | $observer->notify($event,$msg); |
---|
101 | } |
---|
102 | } |
---|
103 | |
---|
104 | } |
---|
105 | |
---|
106 | } |
---|
107 | ?> |
---|