VelocityBuilder is a plugin for Eclipse to generate output files from input files using Velocity. An Eclipse Builder will provide for regeneration of the output files if the input file changes.

It uses a very flexible concept called Template Mappings. A 'Template Mapping' specifies how a Velocity Template is matched to an input file, how the velocity context is provided from the input file and where the output file should go.

Once this is set up, VelocityBuilder watches for changes in participant files and updates the generated output automatically.

Generated files could include Java Source Code, HTML, JSPs, XML, Reports, whatever fits in a file.

For an Input Source Velocity provides the concept of a 'ContextAdapter'. A Context Adapter takes a generation source file, parses it and provides a Java Object representing this source file. The resulting Java Object is set into the velocity context.

Currently there are not many context adapters available, actually there is only one to demonstrate/test the Eclipse extension point, but I can imagine quite a lot (and *you* can contribute your context adapter as Eclipse Plugin):

• EMF Model Context Adapter: loads an emf model file and sets the corresponding model into the velocity context
• XML Context Adapter: loads an XML file and sets the DOM into the velocity context
• QDox Context Adapter: parses a Java Source File and sets the resulting QDox model into the velocity context
• Slime UML Context Adapter: parses a Slime UML diagram and makes the diagram items available in the Velocity context

You can download the current version at SourceForge, I have set up a demo project in the SourceForge CVS to see how it works using a very primitive Context Adapter for specifying value Objects.

The Demo Project is an Eclipse 3.1 Project called BuilderTest.