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