plovr: Lowering the Barrier to Entry for Closure

In drafting Closure: The Definitive Guide, it became pretty obvious that it was not easy to get up and running with Closure. Currently, using the full suite of Closure Tools requires checking out three projects from code.google.com via Subversion, and a combination of Python and Java to compile JavaScript code.

Over the past month, I have been working on a build tool that integrates the Closure Compiler, Closure Library, and Closure Templates into a single download. It is named plovr, and can be downloaded as a single jar file that can be run with the JRE.

In creating plovr, I tried to address problems that frequently appeared in the discussion groups, such as:

• having access to an open-source version of the Closure Compiler service
  
• help in using the Compiler to break a large JavaScript file into modules that can be dynamically loaded
  
• avoiding long lists of command line arguments
  

To this end, plovr can be run both as a server during development that dynamically recompiles Soy and JavaScript files when you reload a web application that depends on them. It can also be used as a command line build tool to generate compiled JavaScript. Because there are so many configurable options when using Closure, options are specified in a JSON config file rather than on the command line.

Like many open-source projects, the documentation is still under development, though hopefully it is enough to get you started. I am also reluctant to commit to official documentation before getting feedback from more developers, so please download it and try it out! I have found plovr to be particularly effective in facilitating my Closure development, but I would like to hear whether it is meeting your needs before I promote it from alpha to beta software.

And if you are planning on entering the contest to see what you can build with 1K of JavaScript, I strongly urge you to use plovr to help you stay under the 1K limit. I am planning to release a new feature of plovr in the next week or two that will expose more features of the Compiler that will help you minify your code for the contest. Stay tuned!