IE7: 'null' is null or not an object

Hi,

I have some very simple code: An autoload tab inside a tabpanel inside a window.

On IE7 it's throwing a 'null' is null or not an object error.

This seems to be a bug. The code works fine in Fx and Chrome.

Code:

---

Ext.onReady(function () {
    var myWindow = new Ext.Window({
        id: "MyWindow",
        hidden: false,
        height: 550,
        width: 750,
        layout: "fit",
        items: new Ext.TabPanel({
            id: "IBMTabPanel",
            activeTab: 0,
            items: [{
                id: "IBMTab2",
                title: "IBM Tab",
                xtype: "panel",
                autoLoad: {
                    url: "http://www.ibm.com"
                }
            }]
        })
    });
});

---

I'm using Windows XP, IE7, ExtJS 3.2.0 to simulate this error.

You can't autoLoad from a different domain, it uses an Ajax request: https://developer.mozilla.org/En/Sam...for_JavaScript

The exception occurs even if I use the same domain. The www.ibm.com was only for demo purposes. Anyway, the XHR exception would be something totally else, like 'Access Denied'.

If I change the url to some local page it works fine for me. Follow the stack trace and see what's causing it.

Ok, sorry, maybe I should have given more detail upfront, but I wanted to keep it simple.

I'm using Ext.NET v1, and the code I posted above was a reduced test case of the problem I'm experiencing.

I see only now that Ext.NET is overriding Panel so that you can load content in an iframe inside a Panel (e.g. it adds a isIFrame method).

It's when I use iframed content that I experience the problem. So I'm not sure whether the bug itself is in ExtJS or Ext.NET.

In any case, this is the part which bombs out in IE7:

Code:

---

// private
    layout : function(){
        var ct = this.container, target = ct.getLayoutTarget();
        if(!(this.hasLayout || Ext.isEmpty(this.targetCls))){
            target.addClass(this.targetCls);
        }
        this.onLayout(ct, target);
        ct.fireEvent('afterlayout', ct, this);
    },

---

The problem is that this.container == null

Is this an ExtJS or Ext.NET bug?