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                 xhr.open('GET', url, true);
  58
  59                 if (!isNaN(timeout))
  60                         xhr.timeout = timeout;
  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                 xhr.open('POST', url, true);
  96
  97                 if (!isNaN(timeout))
  98                         xhr.timeout = timeout;
  99
 100                 xhr.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
 101                 xhr.send(code);
 102         }
 103
 104         this.cancel = function()
 105         {
 106                 this._xmlHttp.onreadystatechange = function(){};
 107                 this._xmlHttp.abort();
 108         }
 109
 110         this.send_form = function(form,callback,extra_values)
 111         {
 112                 var code = '';
 113
 114                 for (var i = 0; i < form.elements.length; i++)
 115                 {
 116                         var e = form.elements[i];
 117
 118                         if (e.options)
 119                         {
 120                                 code += (code ? '&' : '') +
 121                                         form.elements[i].name + '=' + encodeURIComponent(
 122                                                 e.options[e.selectedIndex].value
 123                                         );
 124                         }
 125                         else if (e.length)
 126                         {
 127                                 for (var j = 0; j < e.length; j++)
 128                                         if (e[j].name) {
 129                                                 code += (code ? '&' : '') +
 130                                                         e[j].name + '=' + encodeURIComponent(e[j].value);
 131                                         }
 132                         }
 133                         else
 134                         {
 135                                 code += (code ? '&' : '') +
 136                                         e.name + '=' + encodeURIComponent(e.value);
 137                         }
 138                 }
 139
 140                 if (typeof extra_values == 'object')
 141                         for (var key in extra_values)
 142                                 code += (code ? '&' : '') +
 143                                         key + '=' + encodeURIComponent(extra_values[key]);
 144
 145                 return(
 146                         (form.method == 'get')
 147                                 ? this.get(form.getAttribute('action'), code, callback)
 148                                 : this.post(form.getAttribute('action'), code, callback)
 149                 );
 150         }
 151
 152         this._encode = function(obj)
 153         {
 154                 obj = obj ? obj : { };
 155                 obj['_'] = Math.random();
 156
 157                 if (typeof obj == 'object')
 158                 {
 159                         var code = '';
 160                         var self = this;
 161
 162                         for (var k in obj)
 163                                 code += (code ? '&' : '') +
 164                                         k + '=' + encodeURIComponent(obj[k]);
 165
 166                         return code;
 167                 }
 168
 169                 return obj;
 170         }
 171 }
 172
 173 XHR.get = function(url, data, callback)
 174 {
 175         (new XHR()).get(url, data, callback);
 176 }
 177
 178 XHR.poll = function(interval, url, data, callback, post)
 179 {
 180         if (isNaN(interval) || interval < 1)
 181                 interval = 5;
 182
 183         if (!XHR._q)
 184         {
 185                 XHR._t = 0;
 186                 XHR._q = [ ];
 187                 XHR._r = function() {
 188                         for (var i = 0, e = XHR._q[0]; i < XHR._q.length; e = XHR._q[++i])
 189                         {
 190                                 if (!(XHR._t % e.interval) && !e.xhr.busy())
 191                                         e.xhr[post ? 'post' : 'get'](e.url, e.data, e.callback, e.interval * 1000 - 5);
 192                         }
 193
 194                         XHR._t++;
 195                 };
 196         }
 197
 198         var e = {
 199                 interval: interval,
 200                 callback: callback,
 201                 url:      url,
 202                 data:     data,
 203                 xhr:      new XHR()
 204         };
 205
 206         XHR._q.push(e);
 207         XHR.run();
 208
 209         return e;
 210 }
 211
 212 XHR.stop = function(e)
 213 {
 214         for (var i = 0; XHR._q && XHR._q[i]; i++) {
 215                 if (XHR._q[i] === e) {
 216                         e.xhr.cancel();
 217                         XHR._q.splice(i, 1);
 218                         return true;
 219                 }
 220         }
 221
 222         return false;
 223 }
 224
 225 XHR.halt = function()
 226 {
 227         if (XHR._i)
 228         {
 229                 /* show & set poll indicator */
 230                 try {
 231                         document.getElementById('xhr_poll_status').style.display = '';
 232                         document.getElementById('xhr_poll_status_on').style.display = 'none';
 233                         document.getElementById('xhr_poll_status_off').style.display = '';
 234                 } catch(e) { }
 235
 236                 window.clearInterval(XHR._i);
 237                 XHR._i = null;
 238         }
 239 }
 240
 241 XHR.run = function()
 242 {
 243         if (XHR._r && !XHR._i)
 244         {
 245                 /* show & set poll indicator */
 246                 try {
 247                         document.getElementById('xhr_poll_status').style.display = '';
 248                         document.getElementById('xhr_poll_status_on').style.display = '';
 249                         document.getElementById('xhr_poll_status_off').style.display = 'none';
 250                 } catch(e) { }
 251
 252                 /* kick first round manually to prevent one second lag when setting up
 253                  * the poll interval */
 254                 XHR._r();
 255                 XHR._i = window.setInterval(XHR._r, 1000);
 256         }
 257 }
 258
 259 XHR.running = function()
 260 {
 261         return !!(XHR._r && XHR._i);
 262 }