Extending Eclipse with Helpful Views

s a developer, one of the most important tools at your disposal is your IDE. As a Java developer, there are several IDEs available—both commercial and open source—that are each interesting in their own way and generally extendable. IDE extensions are so valuable because they allow you to create new functionality not offered by the base IDE.

In this article, I will explain how to extend one such IDE, Eclipse, using its plugin architecture. The Eclipse API is vast and can hardly be covered in a single book much less an article, so this article will focus on one specific concept known as views. I will cover creating two views that enable a developer to evaluate expressions in real time. The first view will evaluate a regular expression (RegEx) against arbitrary text and display the results. The second view will evaluate an XPath against an XML document and display the results.

In Eclipse, your main window is known as the workbench. The workbench provides a menu bar, tool bar, and a specialized view known as a perspective. A perspective is simply a collection of views organized in a layout. Each of these views provides a unique set of functionality, e.g. the Navigator view provides a tree-based view of a project's directory allowing manipulation of files. There are many different perspectives in Eclipse, each with a different set of views associated with them. However, any perspective can be customized by the user through the addition and removal of views. The views that you create in this article will simply be added to the choice of views provided to the user.