Rational Application Developer allows custom JSP tag writers to have a visual representation of their tags at design time. This helps in developing JSPs by showing you how the page will look once it is published. You do not need to make any changes in developing JSPs to take advantage of this feature.

To provide this functionality for toolkit JSP developers, there is a WebSphere Studio plug-in project that contains the API with the Java classes that implement the visualizers. Each toolkit custom JSP tag has a corresponding visualizer, and each visualizer has its own Java class implementation.

To take advantage of this feature when developing JSPs, create a Web Project in the Page Designer in Rational Application Developer. When you click the Design tab, the Page Designer design view will read the visualizer of each custom tag used in the JSP, and you will see the visual representation.

Each JSP custom tag has a corresponding visual custom tag. Each of these visualizers has a Java class with the same name, contained in the com.ibm.btt.gui.jsptags.vct package. The following is the list of visual custom tags:

Most of these classes extend com.ibm.etools.webedit.vct.CustomTagVisualizer (imported with the Page Designer plug-in). SelectableTableTagVisualizer and EditableTableTagVisualizer extend TableTagVisualizer, which extends CustomTagVisualizer.

If you are creating your own visual custom tags, each class must implement the doEnd() method, which renders the visual representations. They must also implement the isReadOnlyVisual() method, which must return false. The Java classes use XERCES DOM to build the HTML structure that is rendered at design time.