http://www.archiefleeuwardercourant.nl/resources/scripts/net.js

1/*
2url-loading object and a request queue built on top of it
3*/
4
5/* namespacing object */
6var net=new Object();
7
8net.READY_STATE_UNINITIALIZED=0;
9net.READY_STATE_LOADING=1;
10net.READY_STATE_LOADED=2;
11net.READY_STATE_INTERACTIVE=3;
12net.READY_STATE_COMPLETE=4;
13
14
15/*--- content loader object for cross-browser requests ---*/
16net.ContentLoader=function(url,onload,onerror,method,params,contentType){
17  this.req=null;
18  this.onload=onload;
19  this.onerror=(onerror) ? onerror : this.defaultError;
20  this.loadXMLDoc(url,method,params,contentType);
21}
22
23net.ContentLoader.prototype.loadXMLDoc=function(url,method,params,contentType){
24  if (!method){
25    method="GET";
26  }
27  if (!contentType && method=="POST"){
28    contentType='application/x-www-form-urlencoded';
29  }
30  if (window.XMLHttpRequest){
31    this.req=new XMLHttpRequest();
32  } else if (window.ActiveXObject){
33    this.req=new ActiveXObject("Microsoft.XMLHTTP");
34  }
35  if (this.req){
36    try{
37      var loader=this;
38      this.req.onreadystatechange=function(){
39        net.ContentLoader.onReadyState.call(loader);
40      }
41      this.req.open(method,url,true);
42      if (contentType){
43        this.req.setRequestHeader('Content-Type', contentType);
44      }
45      this.req.send(params);
46    }catch (err){
47      this.onerror.call(this);
48    }
49  }
50}
51
52
53net.ContentLoader.onReadyState=function(){
54  var req=this.req;
55  var ready=req.readyState;
56  if (ready==net.READY_STATE_COMPLETE){
57    var httpStatus=req.status;
58    if (httpStatus==200 || httpStatus==0){
59      this.onload.call(this);
60    }else{
61      this.onerror.call(this);
62    }
63  }
64}
65
66net.ContentLoader.prototype.defaultError=function(){
67  alert("error fetching data!"
68    +"\n\nreadyState:"+this.req.readyState
69    +"\nstatus: "+this.req.status
70    +"\nheaders: "+this.req.getAllResponseHeaders());
71}