how ext maintains its cross-browser compatibility

 

Spacer image

Before we proceed any further, we should provide Ext with something it needs—a

spacer image. Ext needs a 1 pixel by 1 pixel, transparent, GIF image to stretch in

different ways, giving a fixed width to its widgets. We need to set the location of this

spacer image using the following line:

Ext.onReady(function(){

Ext.BLANK_IMAGE_URL = 'images/s.gif';

});

You're probably wondering why we need a spacer image at all. The user interface of

Ext is created using CSS, but the CSS needs underlying HTML elements to style so

that it can create the look and feel of Ext components. The one HTML element that

is an exact, predictable size across all browsers is an image. So an image is used

to define how an Ext component is drawn. This is a part of how Ext maintains its

cross-browser compatibility.