ExtJS is also more than just a widget library because many of the underlying components
to these widgets can be used on their own as application conveniences such as the built-in
DOM tools, the event handling, the state management classes, or the data format classes for
XML or JSON handling.
CHAPTER 4 n LIBRARIES 95
Figure 4-6. A photo album using the ExtJS TreePanel
New Libraries
Of course, nobody is ever content to leave well enough alone??”and probably for good reason.
Libraries are continually tweaked and added upon to meet the needs of the ever-growing
number of people using these libraries. Inevitably, some will attempt to make their own
library to address the needs that libraries before them haven??™t met.
Base2.DOM
Dean Edwards, a man who has contributed heavily to the popularity of JavaScript (including
his IE7Scripts that aim to fix CSS issues in IE 6 and IE 7), has come up with his own DOM tools
(http://dean.edwards.name/weblog/2007/03/yet-another).
Dean takes a different approach to developing a library: build an API that matches that
of the World Wide Web Consortium (W3C) and JavaScript 1.5 (http://developer.mozilla.
org/en/docs/Core_JavaScript_1.5_Reference), the idea being to support features such as
addEventListener() or Array.forEach() that some browsers don??™t yet support (but hopefully
will). As new browsers come online that support these features, that portion of the library
becomes no longer necessary, yet no code that depended on the library has to change.
Pages:
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160