Tag Archives: JavaScript

JQuery Plugin: Polling with timeouts

Leave a reply

Polls a server resource at specified timeout interval until abortTimeOut is reached with options for testing responses for success.

This was useful for allowing a machine a certain amount of time to wake from hibernate before aborting.

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

 /** 
 * PollingWithTimeouts - Polls a server resource at specified timeout 
 * interval until abortTimeOut is reached
 *
 * Settings -:
 * url -          the url to ajax call
 * method -       get/post (defaults to get)
 * sendData -     array of values to be passed in - 
 *                e.g. {name: "foo", something: "else"}
 * timeout -      timeout in ms between each poll (default 1000)
 * type -         json/text/xml what you are expecting as a 
 *                response (default json)
 * abortTimeOut - how long in total before we completely give up in 
 *                milliseconds (default 60000) to have no abort 
 *                timeout dont pass in abortCallBack or testCallBack
 *
 *
 * Usage -:
 *
 * 1) As a never ending poll
 * $(document).ready(function(){
 *       $.PollingWithTimeouts({
 *              url : '/foo/',
 *              sendData:  {foo: 'foo', etc: 'etc'}
 *       });
 * })
 *
 * 2) As a never ending poll with a pollCallBack (stock ticker for example)
 * $(document).ready(function(){
 *       $.PollingWithTimeouts({
 *              url : '/foo/',
 *              sendData:  {foo: 'foo', etc: 'etc'}
 *       },
 *       function(pollCallBackData) { alert(pollCallBackData); }
 *   );
 * })
 *
 * 3) As a poll with an (optional) pollCallBack that aborts after the 
 * specified time calling back to the (optional) abortCallBack
 * 
 * $(document).ready(function(){
 *       $.PollingWithTimeouts({
 *              url : '/foo/',
 *              sendData:  {foo: 'foo', etc: 'etc'},
 *              abortTimeOut: 60000
 *       },
 *       function(pollCallBackData) { alert(pollCallBackData); },
 *       function(abortCallBackData) { alert(abortCallBackData); },
 *   );
 * })
 *
 * 4) As a poll with a call back that aborts after the specified time 
 * calling back to the abort function isCompletedCallBackData allows the 
 * caller to test response data and return true if polling is complete
 *    If isCompletedCallBack is true it calls the successCallBack
 *    e.g. (and the reason I wrote it) after doing WOL on 
 * machine poll the server to ping and determine if the machine is awake. 
 * This needs to abort after a period of time.
 * $(document).ready(function(){
 *     $.PollingWithTimeouts({
 *              url : '/foo/',
 *              sendData:  {foo: 'foo', etc: 'etc'},
 *              abortTimeOut: 60000
 *     },
 *     function(pollCallBackData) { alert(pollCallBackData); },
 *     function(abortCallBackData) { alert(abortCallBackData); },
 *     function(isCompletedCallBackData) {alert(isCompletedCallBackData);},
 *     function(successCallBackData) { alert(successCallBackData); },
 *   );
 * })
 *
 * Copyright (c) 2011 UKOLN (http://www.ukoln.ac.uk)
 * Mark Dewey
 * Licensed under GPL:
 * http://www.gnu.org/licenses/gpl.html
 *
 * Version: 0.9
 */
 
(function($) {
    $.PollingWithTimeouts = function(options, pollCallBack, 
                      abortCallBack, isCompletedCallBack, successCallBack) {
 
            settings = jQuery.extend({
                url: '',        // URL of ajax request
                method: 'get', // get or post
                sendData: '',   // array of values to be passed in 
                                //e.g. {name: "foo", something: "else"}
                timeout: 1000,   // timeout in milliseconds - 1 sec
                type: 'json', //or whatever else you like
                abortTimeOut: 60000  //1 min
            }, options);
 
                f = settings.method == 'post' 
                     || settings.method == 'POST' ? $.post : $.get;
 
                var abort = new Date().getTime() + settings.abortTimeOut;
                getdata();
 
                function getdata()
        {
 
                        f(settings.url, settings.sendData, function(d){
 
                if (abortCallBack && 
                          new Date().getTime() > abort) {
                        clearTimeout(PollingWithTimeouts);
                        abortCallBack(d);
                }
                else {
                        if (isCompletedCallBack) {
                                if (isCompletedCallBack(d)) {
                                        clearTimeout(PollingWithTimeouts);
                                        if (successCallBack) {
                                                successCallBack(d);
                                        }
                                } else {
                                        if (pollCallBack) {
                                                pollCallBack(d);
                                        }
                                        PollingWithTimeouts 
                                           = setTimeout(getdata, 
                                               settings.timeout);
                                }
                        } else {
                                if (pollCallBack) {
                                        pollCallBack(d);
                                }
                                PollingWithTimeouts = setTimeout(getdata, 
                                                         settings.timeout);
                        }
                }
            }, settings.type)
        }
 
        };
})(jQuery);