Moving From Ruby-in-XPages to Polyglot
Wed Dec 12 14:47:28 EST 2012
I've tweeted about this a couple times, but in some of my spare time lately I've put together a new, cleaner implementation of the generic-scripting-language support I first created back when I did my original work with Ruby. I named the new project "Polyglot" and it has two facets:
- The aforementioned generic-scripting-language support, done more cleanly and with better capabilities.
- A method for storing standalone page-generating scripts as documents in the database that are executed in the context of an XPage.
Generic Scripting Languages
With the usual when-I-get-around-to-it caveat, I plan to use Polyglot to entirely supplant Ruby-in-XPages, since its JSR-223-based features cover JRuby as well. The main thing I need to check on is proper memory usage - the embedding mechanism I originally used provides clear control over the lifetime of the scripting runtime, while JSR 223 does not. That may be fine, since it may properly manage itself, but it makes me a bit nervous.
I'll also have to work out proper context variable access (e.g. "database", "currentDocument", etc.). Some languages (Ruby, namely) seem to have gained a magic power since last I checked to access those variables without having to add special support, but I need to figure out if others work the same way or if I need to try an idea for an adapter I had.
In addition to the JSR 223 languages, I also just today added support for formula language via #{formula: ... } bindings, since I realized that that was exceedingly easy to do. For that one, I didn't bother binding it to the contextual variables, but instead just have it look for "currentDocument" - if it's present, it passes the lotus.domino.Document
from that to the session.evaluate(...)
call; if it's not, it forgoes the second parameter. I don't expect I'll use that binding much, but it was fun to add.
Standalone Scripts
The standalone script support is a little different - the idea is that, rather than working another language into an XPage, you write a script entirely in the other language, much like you might do with, say, PHP (don't use PHP). You can write a script using a basic editor, it's stored in a document in the database, and then you can execute it in the context of a ScriptRunner XPage, meaning you have the same Java environment as usual (with the same caveat as above that I need to sort out variable access).
Besides the usual suite of JSR 223 languages, I've also started working on integrating the XSP parser from the XPages Bazaar, both as a way to familiarize myself with the Bazaar and to see if there's any use in a setup where your XSP markup is stored in documents and evaluated at runtime rather than design elements compiled in Designer. Maybe, maybe not, but it's a fun test.
For now, it's still in an "experimental" state, but eventually I hope to cobble it into a proper releasable state and have it supersede Ruby-in-XPages entirely.