tailieunhanh - JavaScript Bible, Gold Edition part 134

JavaScript Bible, Gold Edition part 134. This book will bring programmers and non-technical professionals, including casual programmers and scripters, painlessly up to speed on all aspects of mastering JavaScript. Key topics include programming fundamentals, JavaScript language elements and how to use them effectively, and how to easily and efficiently add powerful new functionality to HTML documents and Java applets. | 1178 Part V Putting JavaScript to Work Such a broad swath of browsers not supporting the feature especially the IE for Macintosh which has been factory-installed as the default browser on millions of Macs makes it difficult to design a public Web application that relies on LiveConnect features. Design your pages accordingly. The internal mechanisms that allow scripts to communicate with applets and plug-ins are quite different for NN and IE. NN3 and NN4 relied exclusively on the Java virtual machine JVM that shipped with most OS platform versions of the browsers. In NN4 the JVM doesn t load until it is needed sometimes causing a brief delay in initial execution. For the most part though the underlying Java engine is invisible to the scripter you and certainly to the visitors of your sites. At most visitors see statusbar messages about applets loading and running. IE Windows on the other hand has its own internal architecture for communicating between processes. To Windows most processes are treated as components that have properties and methods accessible to other components. Whether you use the technology to communicate with a Java applet or an ActiveX control the advantage to you as an author is that LiveConnect extends the document object model to include objects and data types that are not a part of the HTML world. HTML for instance does not have a form element that displays realtime stock ticker data nor does HTML have the capability to treat a sound file like anything more than a URL to be handed off to a helper application. With LiveConnect however your scripts can treat the applet that displays the stock ticker as an object whose properties and methods can be modified after the applet loads scripts can also tell the sound when to play or pause by controlling the plugin that manages the incoming sound file. Why Control Java Applets A question I often hear from experienced Java programmers is Why bother controlling an applet via a script when you can build .