Linux Magazine's JVM Web Framework Smackdown article... "compares three of the most promising modern Java frameworks: JRuby on Rails (JRoR) ; Grails, powered by Groovy ; and Helma, with Rhino JavaScript "...
The article covers the fundamentals...
Helma... "uses Rhino JavaScript, the oldest language on the JVM besides Java itself. Rhino was created by Netscape and later inherited by the Mozilla Foundation. It is backed by Google, and it is the default scripting language implementation available in Java 6. It offers strong performance and a rich set of utilities, all of which Helma leverages beautifully."
"Helma was the easiest to get up and running. Once you download the package, run ./start.sh [...] and navigate to http://localhost:8080/ to find a page with links to various tools, documentation, and the Helma website."
...attempts to explain Helma concepts...
"The biggest challenge learning Helma is shifting your mode of thinking—not entirely different from first learning JavaScript’s prototype-based object system. Most frameworks are written in object-oriented languages; Helma is an object-oriented framework. It is a subtle, but critical distinction. With Helma, you build one massive object that is the web application. While confusing at first, the final organization seems very intuitive."
...finds some things to reasonably gripe about...
"Helma’s organization does lead to some weird cases. For instance, consider registering a new user. This should obviously be an action placed under the User prototype. Right? Wrong. Every User action must match up to an existing user. Therefore the registerUser action must be stored in Root. As a result, this directory can feel like a random grab-bag.
In theory, you could avoid this issue by creating a default object and cloning it. This would fit nicely with the cloning-based approach of prototype-based object systems, but it does not seem to be the standard for Helma."
...and concludes...
"[...] developing an application in Helma was a pleasure. The organization, while unusual, was also very powerful and will challenge your assumptions about how web development should be done. [...] While its libraries are decent, they pale compared to Rails and Grails. Still, it was the most fun to develop in."
6.9.2009, 17:12