# Developing Tag Library Extensions

A tag library extension integrates a custom JSP tag library with the WebLogic Workshop development environment. JSP developers use tags in your library for declarative access to Java-based logic; your corresponding library extension connects the tags in the library to IDE support that makes using them easier. This support includes:

- Visibility on the Palette and Data Palette.
- Error checking in Source View.
- Custom tag rendering in the JSP designer.
- A custom property builder accessible through the Property Editor.

## TLDX File and Extension Classes

A tag library includes a Tag Library Descriptor (TLD) file to describe the library's tags and their handlers. When you extend the tag library to include IDE support, you add a Tag Library Descriptor Extension (TLDX) file to describe the IDE functionality supported and to point to the Java classes that contain the extension logic. You implement the TLD and tag handlers just as you ordinarily would; the TLDX and supporting classes simply provide IDE support.

To compare a TLD and TLDX file, see the examples in the ExtensionDevKit set of sample applications. Open the TaglibExtDevKit sample application. There, under TaglibWebProject/WEB-INF, compare the TLD and TLDX files, including tdk-tags.tldx and tdk-tags.tld, which accompany sample extensions. You'll see that the TLDX format mirrors and extends the corresponding TLD file with extra properties. For more information about the specific properties available in a TLDX file, see TLDX File Contents.

See Tag Library Extension Samples for more information on building and running the sample tag library extension included in this kit.

## Integrating Custom Tag Library Documentation

You can integrate documentation for your custom tags so that those topics are visible in the WebLogick Workshop help browser. The file at TaglibExtDevKit/TldxHandlers/resources/META-INF/extension.xml specifies a directory that the IDE should look for help files. As noted in the sample build instructions in Tag Library Extension Samples, the help index must be recreated for the extension help to be recognized. Once you have done this, select Help Topics from the Help menu. The TDK help files will appear under the "Custom Controls" topic

Note: In the GA release of WebLogic Platform 8.1, custom tag libraries will not have their own topic heading in the table of contents.

Related Topics

None.