modules/luci-base/htdocs/luci-static/resources/xhr.js

   1 /*
   2  * xhr.js - XMLHttpRequest helper class
   3  * (c) 2008-2010 Jo-Philipp Wich
   4  */
   5
   6 XHR = function()
   7 {
   8         this.reinit = function()
   9         {
  10                 if (window.XMLHttpRequest) {
  11                         this._xmlHttp = new XMLHttpRequest();
  12                 }
  13                 else if (window.ActiveXObject) {
  14                         this._xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
  15                 }
  16                 else {
  17                         alert("xhr.js: XMLHttpRequest is not supported by this browser!");
  18                 }
  19         }
  20
  21         this.busy = function() {
  22                 if (!this._xmlHttp)
  23                         return false;
  24
  25                 switch (this._xmlHttp.readyState)
  26                 {
  27                         case 1:
  28                         case 2:
  29                         case 3:
  30                                 return true;
  31
  32                         default:
  33                                 return false;
  34                 }
  35         }
  36
  37         this.abort = function() {
  38                 if (this.busy())
  39                         this._xmlHttp.abort();
  40         }
  41
  42         this.get = function(url,data,callback,timeout)
  43         {
  44                 this.reinit();
  45
  46                 var xhr  = this._xmlHttp;
  47                 var code = this._encode(data);
  48
  49                 url = location.protocol + '//' + location.host + url;
  50
  51                 if (code)
  52                         if (url.substr(url.length-1,1) == '&')
  53                                 url += code;
  54                         else
  55                                 url += '?' + code;
  56
  57                 if (!isNaN(timeout))
  58                         xhr.timeout = timeout;
  59
  60                 xhr.open('GET', url, true);
  61
  62                 xhr.onreadystatechange = function()
  63                 {
  64                         if (xhr.readyState == 4) {
  65                                 var json = null;
  66                                 if (xhr.getResponseHeader("Content-Type") == "application/json") {
  67                                         try {
  68                                                 json = eval('(' + xhr.responseText + ')');
  69                                         }
  70                                         catch(e) {
  71                                                 json = null;
  72                                         }
  73                                 }
  74
  75                                 callback(xhr, json);
  76                         }
  77                 }
  78
  79                 xhr.send(null);
  80         }
  81
  82         this.post = function(url,data,callback,timeout)
  83         {
  84                 this.reinit();
  85
  86                 var xhr  = this._xmlHttp;
  87                 var code = this._encode(data);
  88
  89                 xhr.onreadystatechange = function()
  90                 {
  91                         if (xhr.readyState == 4)
  92                                 callback(xhr);
  93                 }
  94
  95                 if (!isNaN(timeout))
  96                         xhr.timeout = timeout;
  97
  98                 xhr.open('POST', url, true);
  99                 xhr.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
 100                 xhr.send(code);
 101         }
 102
 103         this.cancel = function()
 104         {
 105                 this._xmlHttp.onreadystatechange = function(){};
 106                 this._xmlHttp.abort();
 107         }
 108
 109         this.send_form = function(form,callback,extra_values)
 110         {
 111                 var code = '';
 112
 113                 for (var i = 0; i < form.elements.length; i++)
 114                 {
 115                         var e = form.elements[i];
 116
 117                         if (e.options)
 118                         {
 119                                 code += (code ? '&' : '') +
 120                                         form.elements[i].name + '=' + encodeURIComponent(
 121                                                 e.options[e.selectedIndex].value
 122                                         );
 123                         }
 124                         else if (e.length)
 125                         {
 126                                 for (var j = 0; j < e.length; j++)
 127                                         if (e[j].name) {
 128                                                 code += (code ? '&' : '') +
 129                                                         e[j].name + '=' + encodeURIComponent(e[j].value);
 130                                         }
 131                         }
 132                         else
 133                         {
 134                                 code += (code ? '&' : '') +
 135                                         e.name + '=' + encodeURIComponent(e.value);
 136                         }
 137                 }
 138
 139                 if (typeof extra_values == 'object')
 140                         for (var key in extra_values)
 141                                 code += (code ? '&' : '') +
 142                                         key + '=' + encodeURIComponent(extra_values[key]);
 143
 144                 return(
 145                         (form.method == 'get')
 146                                 ? this.get(form.getAttribute('action'), code, callback)
 147                                 : this.post(form.getAttribute('action'), code, callback)
 148                 );
 149         }
 150
 151         this._encode = function(obj)
 152         {
 153                 obj = obj ? obj : { };
 154                 obj['_'] = Math.random();
 155
 156                 if (typeof obj == 'object')
 157                 {
 158                         var code = '';
 159                         var self = this;
 160
 161                         for (var k in obj)
 162                                 code += (code ? '&' : '') +
 163                                         k + '=' + encodeURIComponent(obj[k]);
 164
 165                         return code;
 166                 }
 167
 168                 return obj;
 169         }
 170 }
 171
 172 XHR.get = function(url, data, callback)
 173 {
 174         (new XHR()).get(url, data, callback);
 175 }
 176
 177 XHR.poll = function(interval, url, data, callback, post)
 178 {
 179         if (isNaN(interval) || interval < 1)
 180                 interval = 5;
 181
 182         if (!XHR._q)
 183         {
 184                 XHR._t = 0;
 185                 XHR._q = [ ];
 186                 XHR._r = function() {
 187                         for (var i = 0, e = XHR._q[0]; i < XHR._q.length; e = XHR._q[++i])
 188                         {
 189                                 if (!(XHR._t % e.interval) && !e.xhr.busy())
 190                                         e.xhr[post ? 'post' : 'get'](e.url, e.data, e.callback, e.interval * 1000 - 5);
 191                         }
 192
 193                         XHR._t++;
 194                 };
 195         }
 196
 197         var e = {
 198                 interval: interval,
 199                 callback: callback,
 200                 url:      url,
 201                 data:     data,
 202                 xhr:      new XHR()
 203         };
 204
 205         XHR._q.push(e);
 206         XHR.run();
 207
 208         return e;
 209 }
 210
 211 XHR.stop = function(e)
 212 {
 213         for (var i = 0; XHR._q && XHR._q[i]; i++) {
 214                 if (XHR._q[i] === e) {
 215                         e.xhr.cancel();
 216                         XHR._q.splice(i, 1);
 217                         return true;
 218                 }
 219         }
 220
 221         return false;
 222 }
 223
 224 XHR.halt = function()
 225 {
 226         if (XHR._i)
 227         {
 228                 /* show & set poll indicator */
 229                 try {
 230                         document.getElementById('xhr_poll_status').style.display = '';
 231                         document.getElementById('xhr_poll_status_on').style.display = 'none';
 232                         document.getElementById('xhr_poll_status_off').style.display = '';
 233                 } catch(e) { }
 234
 235                 window.clearInterval(XHR._i);
 236                 XHR._i = null;
 237         }
 238 }
 239
 240 XHR.run = function()
 241 {
 242         if (XHR._r && !XHR._i)
 243         {
 244                 /* show & set poll indicator */
 245                 try {
 246                         document.getElementById('xhr_poll_status').style.display = '';
 247                         document.getElementById('xhr_poll_status_on').style.display = '';
 248                         document.getElementById('xhr_poll_status_off').style.display = 'none';
 249                 } catch(e) { }
 250
 251                 /* kick first round manually to prevent one second lag when setting up
 252                  * the poll interval */
 253                 XHR._r();
 254                 XHR._i = window.setInterval(XHR._r, 1000);
 255         }
 256 }
 257
 258 XHR.running = function()
 259 {
 260         return !!(XHR._r && XHR._i);
 261 }