HTML5 Guidelines for Web Developers

278 Chapter 12—Finishing Touches:Some Global Attributes

Figure 12.1 Static basic layout of the 1-2-3-4! game

As you can see in the title bar in Figure 12.1, the screen shot was created

with a beta version of Firefox 4, because only that browser version meets the

requirements of the game. With the exception of data-*, for which we use Remy

Sharp’s JavaScript shim as mentioned earlier, all necessary attributes and

methods are implemented in this version.

12.5 Drag and Drop with the “draggable” Attribute

Drag and drop in the browser is really nothing new. This function has been pres-

ent in Internet Explorer (IE) since 1999, in version 5.0 at that time. Based on the

IE implementation, drag and drop was then included in the specification in 2005

and is now available in all common browsers, with the exception of Opera.

The checklist for the implementation of a classic drag-and-drop operation, as

used in the game for sorting the cities by number of inhabitants, involves the

following tasks:

1. Selecting elements that can be dragged


2. Determining data to be dragged along in the background as soon as the
   drag-and-drop operation is started

NOTE