/library/History.py
Python | 112 lines | 64 code | 4 blank | 44 comment | 3 complexity | a0ef06f908b066b3d1a13edf4fcca577 MD5 | raw file
Possible License(s): LGPL-2.1, Apache-2.0
1from __pyjamas__ import JS
2
3def init():
4 JS("""
5 $wnd.__historyToken = '';
6
7 // Get the initial token from the url's hash component.
8 var hash = $wnd.location.hash;
9 if (hash.length > 0)
10 $wnd.__historyToken = decodeURIComponent(hash.substring(1));
11
12 // Create the timer that checks the browser's url hash every 1/4 s.
13 $wnd.__checkHistory = function() {
14 var token = '', hash = $wnd.location.hash;
15 if (hash.length > 0)
16 token = decodeURIComponent(hash.substring(1));
17
18 if (token != $wnd.__historyToken) {
19 $wnd.__historyToken = token;
20 // TODO - move init back into History
21 // this.onHistoryChanged(token);
22 var h = new __History_History();
23 h.onHistoryChanged(token);
24 }
25
26 $wnd.setTimeout('__checkHistory()', 250);
27 };
28
29 // Kick off the timer.
30 $wnd.__checkHistory();
31
32 return true;
33 """)
34
35historyListeners = []
36init()
37
38
39class History:
40 """
41 Simple History management class for back/forward button support.
42
43 This class allows your AJAX application to use a history. Each time you
44 call newItem(), a new item is added to the history and the history
45 listeners are notified. If the user clicks the browser's forward or back
46 buttons, the appropriate item (a string passed to newItem) is fetched
47 from the history and the history listeners are notified.
48
49 The address bar of the browser contains the current token, using
50 the "#" seperator (for implementation reasons, not because we love
51 the # mark).
52
53 You may want to check whether the hash already contains a history
54 token when the page loads and use that to show appropriate content;
55 this allows users of the site to store direct links in their
56 bookmarks or send them in emails.
57
58 To make this work properly in all browsers, you must add a specially
59 named iframe to your html page, like this:
60
61 <iframe id='__pygwt_historyFrame' style='width:0;height:0;border:0'></iframe>
62 """
63
64 def addHistoryListener(self, listener):
65 global historyListeners
66 historyListeners.append(listener)
67
68 def back(self):
69 JS("""
70 $wnd.history.back();
71 """)
72
73 def forward(self):
74 JS("""
75 $wnd.history.forward();
76 """)
77
78 def getToken(self):
79 JS("""
80 return $wnd.__historyToken;
81 """)
82
83 def newItem(self, historyToken):
84 JS("""
85 if(historyToken == "" || historyToken == null){
86 historyToken = "#";
87 }
88 $wnd.location.hash = encodeURIComponent(historyToken);
89 """)
90
91 # TODO - fireHistoryChangedAndCatch not implemented
92 def onHistoryChanged(self, historyToken):
93 #UncaughtExceptionHandler handler = GWT.getUncaughtExceptionHandler();
94 #if (handler != null)
95 # fireHistoryChangedAndCatch(historyToken, handler);
96 #else
97 self.fireHistoryChangedImpl(historyToken)
98
99 # TODO
100 def fireHistoryChangedAndCatch(self):
101 pass
102
103 def fireHistoryChangedImpl(self, historyToken):
104 global historyListeners
105
106 for listener in historyListeners:
107 listener.onHistoryChanged(historyToken)
108
109 def removeHistoryListener(self, listener):
110 global historyListeners
111 historyListeners.remove(listener)
112