js/CXGN/Request.js

   1 /**
   2
   3 =head1 NAME
   4
   5 Class: Request
   6
   7 =head1 SYNOPSIS
   8
   9 A simple handler for Async Requests
  10
  11 The returned XML file should contain all information needed to cause a page effect,
  12 rather than creating a custom response for each request, which is not possible due
  13 to the security issues that prevent the creation of instances of XMLHttpRequest()
  14 with unique properties.  It's better this way, anyhow :-/
  15
  16 See XMLRoute.js to write handlers for async responses.
  17
  18 =head1 USAGE
  19
  20 var req = new Request();
  21 if(req.isValid()){
  22         req.send("scraps/add.pl", "?first=3&second=2", "POST");
  23 }
  24
  25 =head1 AUTHOR
  26
  27 Chris Carpita <csc32@cornell.edu>
  28
  29 =cut
  30
  31 */
  32
  33 JSAN.use("CXGN.Base");
  34 JSAN.use("CXGN.XMLroute");
  35
  36 function Request() {
  37
  38         var req = null;
  39         this.valid = false;
  40         var loader = this;
  41
  42         this.isValid = function() { return this.valid }
  43         this._onReadyState = function() {
  44                 if(req.readyState==4){
  45 //                      document.write(req.responseText);
  46                         XMLroute.call(this, req.responseXML);
  47                 }
  48         }
  49         this.send = function(url, parameters, method) {
  50                 if(!method) { method = "POST" }
  51                 if(method == "POST") {
  52                         req.open("POST", url, true);
  53                         req.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
  54                 req.setRequestHeader("Content-length", parameters.length);
  55                 req.setRequestHeader("Connection", "close");
  56                         req.send(parameters);
  57                 }
  58                 else if(method == "GET") {
  59                         req.open("GET", url + parameters, true);
  60                         req.send(null);
  61                 }
  62         }
  63         if(window.XMLHttpRequest) {
  64                 req = new XMLHttpRequest();
  65         }
  66         else if (window.ActiveXObject) {
  67                 try { req = new ActiveXObject("Msxml2.XMLHTTP");}
  68                 catch(e) {
  69                         try { req = new ActiveXObject ("Microsoft.XMLHTTP");}
  70                         catch (e) { return false }
  71                 }
  72         }
  73         if(req) {
  74                 this.valid = true;
  75                 req.onreadystatechange = function() { loader._onReadyState.call() }
  76                 return true;
  77         }
  78         else { return false }
  79 }
  80