WHAT’S IN THIS CHAPTER?
- Understanding event flow
- Working with event handlers
- Examining the different types of events
Events first appeared in Internet Explorer 3 and Netscape Navigator 2 as a way to offload some form processing from the server onto the browser. By the time Internet Explorer 4 and Netscape 4 were released, each browser delivered similar but different APIs that continued for several generations. DOM Level 2 was the first attempt to standardize the DOM events API in a logical way. Internet Explorer 9, Firefox, Opera, Safari, and Chrome all have implemented the core parts of DOM Level 2 Events. Internet Explorer 8 was the last major browser to use a purely proprietary event system.
The browser event system is a complex one. Even though all major browsers have implemented DOM Level 2 Events, the specification doesn’t cover all event types. The BOM also supports events, and the relationship between these and the DOM events is often confusing because of a longtime lack of documentation ...