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Domino Applets

Ian Tree  20 March 2006 13:10:56

Domino Applets

Applets are a much misunderstood and too seldom used component in the Notes/Domino developers armoury.

The following is from the Notes Designer Help -

Applets are self-contained Java programs that can run in your Domino application. Java applets are often used to add animation to Web applications. Although Java applets are mostly used for Web applications, you can also include them in the following elements of a Domino application:
  • Form -- The applet is included in each document created with that form.
  • Document -- The applet is available only in the document.
  • Page -- The applet is available only in the page.  

A Java applet usually consists of a collection of files, with one file that contains the main class, or the starting point for the applet. There can also be image files, archive files, and Java source files. You can store Java applet files as follows:
  • When you import an applet, the files are attached as hidden files to the form, document, or page where you include the Java applet.
  • When you link to an applet, files are stored on the Web and a URL reference to those files is stored in the form, document, or page where you include the Java applet.
  • When you set up shared applet resources, the files are stored in the database where you include the Java applets that use those files.

Requirements and restrictions for Java applets

Java applets are supported for most releases of Internet Explorer 4.x and 5.x and Netscape Navigator 4.x. Browser support is platform dependent. For the latest information on supported browsers, see the topic "Supported Web browsers" in the Release Notes.
Java applets created with Notes 4.6 and later will not work with previous releases of Notes, unless the applet is stored on the Web and it has no parameters.
Notes 6.0 and later support Java Virtual Machine (JVM) version 1.3.

Notice the use of the word "Animation" in the first paragraph, this immediately conjours the idea of moving images, which may seem a slightly trivial topic to deserve much attention. However "Animation" in it's wider context includes any display elements that change over time. Also, the use of Applets allow the use of any "exotic" AWT, Swing or other Java display components as a part of a static or dynamic display in a Notes application.

In the first example below we shall look at the creation of dynamic display components in a Notes Application.


Example #1  - Dynamic Display