modules/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)
  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                 xhr.onreadystatechange = function()
  60                 {
  61                         if (xhr.readyState == 4) {
  62                                 var json = null;
  63                                 if (xhr.getResponseHeader("Content-Type") == "application/json") {
  64                                         try {
  65                                                 json = eval('(' + xhr.responseText + ')');
  66                                         }
  67                                         catch(e) {
  68                                                 json = null;
  69                                         }
  70                                 }
  71
  72                                 callback(xhr, json);
  73                         }
  74                 }
  75
  76                 xhr.send(null);
  77         }
  78
  79         this.post = function(url,data,callback)
  80         {
  81                 this.reinit();
  82
  83                 var xhr  = this._xmlHttp;
  84                 var code = this._encode(data);
  85
  86                 xhr.onreadystatechange = function()
  87                 {
  88                         if (xhr.readyState == 4)
  89                                 callback(xhr);
  90                 }
  91
  92                 xhr.open('POST', url, true);
  93                 xhr.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
  94                 xhr.setRequestHeader('Content-length', code.length);
  95                 xhr.setRequestHeader('Connection', 'close');
  96                 xhr.send(code);
  97         }
  98
  99         this.cancel = function()
 100         {
 101                 this._xmlHttp.onreadystatechange = function(){};
 102                 this._xmlHttp.abort();
 103         }
 104
 105         this.send_form = function(form,callback,extra_values)
 106         {
 107                 var code = '';
 108
 109                 for (var i = 0; i < form.elements.length; i++)
 110                 {
 111                         var e = form.elements[i];
 112
 113                         if (e.options)
 114                         {
 115                                 code += (code ? '&' : '') +
 116                                         form.elements[i].name + '=' + encodeURIComponent(
 117                                                 e.options[e.selectedIndex].value
 118                                         );
 119                         }
 120                         else if (e.length)
 121                         {
 122                                 for (var j = 0; j < e.length; j++)
 123                                         if (e[j].name) {
 124                                                 code += (code ? '&' : '') +
 125                                                         e[j].name + '=' + encodeURIComponent(e[j].value);
 126                                         }
 127                         }
 128                         else
 129                         {
 130                                 code += (code ? '&' : '') +
 131                                         e.name + '=' + encodeURIComponent(e.value);
 132                         }
 133                 }
 134
 135                 if (typeof extra_values == 'object')
 136                         for (var key in extra_values)
 137                                 code += (code ? '&' : '') +
 138                                         key + '=' + encodeURIComponent(extra_values[key]);
 139
 140                 return(
 141                         (form.method == 'get')
 142                                 ? this.get(form.getAttribute('action'), code, callback)
 143                                 : this.post(form.getAttribute('action'), code, callback)
 144                 );
 145         }
 146
 147         this._encode = function(obj)
 148         {
 149                 obj = obj ? obj : { };
 150                 obj['_'] = Math.random();
 151
 152                 if (typeof obj == 'object')
 153                 {
 154                         var code = '';
 155                         var self = this;
 156
 157                         for (var k in obj)
 158                                 code += (code ? '&' : '') +
 159                                         k + '=' + encodeURIComponent(obj[k]);
 160
 161                         return code;
 162                 }
 163
 164                 return obj;
 165         }
 166 }
 167
 168 XHR.get = function(url, data, callback)
 169 {
 170         (new XHR()).get(url, data, callback);
 171 }
 172
 173 XHR.poll = function(interval, url, data, callback)
 174 {
 175         if (isNaN(interval) || interval < 1)
 176                 interval = 5;
 177
 178         if (!XHR._q)
 179         {
 180                 XHR._t = 0;
 181                 XHR._q = [ ];
 182                 XHR._r = function() {
 183                         for (var i = 0, e = XHR._q[0]; i < XHR._q.length; e = XHR._q[++i])
 184                         {
 185                                 if (!(XHR._t % e.interval) && !e.xhr.busy())
 186                                         e.xhr.get(e.url, e.data, e.callback);
 187                         }
 188
 189                         XHR._t++;
 190                 };
 191         }
 192
 193         XHR._q.push({
 194                 interval: interval,
 195                 callback: callback,
 196                 url:      url,
 197                 data:     data,
 198                 xhr:      new XHR()
 199         });
 200
 201         XHR.run();
 202 }
 203
 204 XHR.halt = function()
 205 {
 206         if (XHR._i)
 207         {
 208                 /* show & set poll indicator */
 209                 try {
 210                         document.getElementById('xhr_poll_status').style.display = '';
 211                         document.getElementById('xhr_poll_status_on').style.display = 'none';
 212                         document.getElementById('xhr_poll_status_off').style.display = '';
 213                 } catch(e) { }
 214
 215                 window.clearInterval(XHR._i);
 216                 XHR._i = null;
 217         }
 218 }
 219
 220 XHR.run = function()
 221 {
 222         if (XHR._r && !XHR._i)
 223         {
 224                 /* show & set poll indicator */
 225                 try {
 226                         document.getElementById('xhr_poll_status').style.display = '';
 227                         document.getElementById('xhr_poll_status_on').style.display = '';
 228                         document.getElementById('xhr_poll_status_off').style.display = 'none';
 229                 } catch(e) { }
 230
 231                 /* kick first round manually to prevent one second lag when setting up
 232                  * the poll interval */
 233                 XHR._r();
 234                 XHR._i = window.setInterval(XHR._r, 1000);
 235         }
 236 }
 237
 238 XHR.running = function()
 239 {
 240         return !!(XHR._r && XHR._i);
 241 }