XMLHttpRequest in Internet Explorer without ActiveX Controls

Wednesday, August 24, 2005 12:18:00 AM

While working on my new library I was looking on the JavaScript code to support more browsers. My first job was to create a XMLHttpRequest wrapper for the Internet Explorer if the "Enable safe ActiveX Controls" settings is disabled. I have done a first example (download script at http://ajax.schwarz-interactive.de/download/xmlhttpifr.js):

var XMLHttpRequest = function()
{
 this.method = "POST";
 this.url = null;
 this.async = true;
 this.iframe = null;
 this.responseText = null;
 this.header = new Object();
 this.id = "_xmlhttp_" + new Date().getTime();
 this.container = document.body;
}

XMLHttpRequest.prototype.open = function(method, url, async)
{
 this.method = method;
 this.url = url;
 this.async = async;
 this.readyState = 0;
 
 this.iframe = document.createElement("IFRAME");
 this.iframe.style.visibility = "hidden";
 this.iframe.id = this.id;
 
 if(document.getElementById(this.id) == null)
  this.container.appendChild(this.iframe);
  
 this.setRequestHeader("___xmlhttp", "iframe");
}

XMLHttpRequest.prototype.setRequestHeader = function(name, value)
{
 // if(typeof(this.header[name]) == "undefined")
  this.header[name] = value;
}

XMLHttpRequest.prototype.send = function(data)
{
 var html = [];
 
 html[html.length] = '<html><body><form method="' + this.method + '" action="' + this.url + '">';
 
 for(name in this.header)
  html[html.length] = '<textarea name="' + name + '">' + this.header[name] + '</textarea>';
 
 if(data != null && data.length > 0)
  html[html.length] = '<textarea name="_data">' + data + '</textarea>';

 html[html.length] = '<s'+'cript>document.forms[0].submit();</s'+'cript>';
 // html[html.length] = '<input type="submit">';
 
 html[html.length] = '</form></body></html>';

 this.iframe._xmlhttp = this;
 this.iframe._xmlhttp._fix = -1;
 this.iframe._xmlhttp.responseText = null;
 this.iframe.onreadystatechange = this._onreadystatechange;
 this.iframe.src = "javascript:document.write('" + html.join('').replace(/\'/g,"\\'").replace(/\r\n/g, "\\r\\n") + "');void(0);";
}

XMLHttpRequest.prototype._onreadystatechange = function()
{
 this._xmlhttp._fix++;
 
 if(this._xmlhttp._fix < 1)
  return;
 
 if(this._xmlhttp._fix == 1)
 {
  this._xmlhttp.readyState = 1;
 }
 else if(this._xmlhttp._fix > 1)
 {
  switch(this.readyState.toString())
  {
   case "loading":
    this._xmlhttp.readyState = 2;
    break;

   case "interactive":
    this._xmlhttp.readyState = 3;
    break;

   case "complete":
    this._xmlhttp.responseText = window.frames[this.id].document.childNodes[0].childNodes[1].innerHTML;
    this.onreadystatechange = function(){}
    this._xmlhttp.readyState = 4;
    break;
  } 
 }
 
 if(typeof(this._xmlhttp.onreadystatechange) == "function")
   this._xmlhttp.onreadystatechange();
}

 

Because using this object the browsers history will be wrong I am changing some parts to use SCRIPT tags instead of IFRAMEs. If you have time it would be great to get any feedback of this script.

3 Comments

  • Maud-Dib said

    Awesome! I had just asked Wally McClure in a voice-mail, and then found this searching with: &quot;AJAX will not work with ActiveX disabled&quot;
    I was translating your page with bablefish from German to English and Wally called to tell me to look at your Wed blog... I was like a few lines from having read your Wed entry! Excellent work Mr Schwarz.

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