Helma NG serverside Javascript framework on appengine

Helma is one of the few Javascript server-side web frameworks, and it's next generation version runs right out-of-the-box on Google appengine. I followed the tutorial and easily got my own Helma NG demo running on appengine. Because Helma NG is a complete rewrite of standard Helma (which doesn't run on appengine), it is very simple, no persistence yet, mostly just request wrapping and routing and a simple template engine (no template inheritance and other fancy feature you find e.g. in django). If this is all one needs then Helma NG on appengine is now probably the easiest way to run javascript at client and server side. So let's hope that those who need a bit more, will contribute to Helma NG development to make it competitive with PHP, django and RubyOnRails, or come up with a new framework (RhinoOnRails ???).

And for those who need less than Helma NG, this article might be helpful.

Update: I was wrong about template inheritance, Helma NG does support it, via the "extends" tag. And the development branch has now also appengine persistence support (demo).

Javascript on appengine

Was offline yesterday, therefore missed to be among the first 10K to try it out, but a bit of web research revealed that it should work right out of the box:

• Dynamic languages on appengine - summary
• Rhino Javascript on appengine - first working example
• JRuby

Update: already got my invitation, now just need time to experiment with it !

Experimenting with lexical auto-indentation for bespin

While the basic features of the codemirror syntaxengine now are part of bespin (and that is just syntax highlighting), I started today to experiment to add an advanced feature: Auto indenting of current line or a selection based on lexical analysis. The user just has to press CTRL + TAB (but could be any other key binding of course). The information about what codemirror thinks is the correct indentation is already internally stored for each line of the source document, all I had to do was to add some code which inserts or deletes some whitespace at the begin of those lines the user marked for auto-indentation. That is at least what I thought. Unfortunately it doesn't work yet reliable (and that is my fault, because the original codemirror editor does perfectly auto-indent) and also is not yet integrated into bespins undo/redo system, so it needs another iteration, before I can submit a patch, but if anybody wants to help working on it, take a look at the auto-indent code I added.