Tapestry

Agility

Developing in Tapestry is fairly agile - changing the page's template or specification (an XML file which describes the components that a page contains) requires that the user hit a "reset" link before seeing the changes, but no recompilation or restart of the appserver is necessary unless the (optional) java backing class is changed.

Support

Tapestry has been around for at least 5 years and has been slowly gaining momentum, especially since the release of 4.0 to beta.

Tapestry powers the theserverside.com and nhl.com, both fairly high-profile sites.

Lately however it seems to have had it's thunder stolen a bit by Sun's JSF - seen by some as the "official" component based web-application framework.

Also, Tapestry's documentation is pretty sparse and out of date right now.

Skinability

Tapestry's component nature makes it easy to pass around blocks of html or tapestry mark up as parameters. We could use this as a way to pass in html to those components that need custom skins

Performance / Scalability

I have had some concerns about Tapestry since unlike JSP based frameworks it doesn't compile (as far as I can tell) pages and heavily uses reflection. However, the use of reflection has decreased significantly with 4.0 and benchmarks have been run (pre 4.0) which put Tapestry at only slightly slower than JSP

I8ln

Integrates nicely with J2SE i8ln. You can even have different templates for different locales, which is unique as far as I know.

Expression / Templating Language

All Tapestry templates are straight html. To make a tag a tapestry tag you just add a jwcid like so:

Welcome <span jwcid="@Insert" value="ognl:firstName">Bobby</span>!

What's nice about this is that if you give try to have a browser render the template as is, it will be able to do so, since it's just straight html.

The expression language is ognl, which can do just about anything java can do in a simplified but familiar syntax.

The one negative thing that comes to mind about this syntax is that you can't simply just write ${firstName} to eval an expression, you have to put in a tag like above - this can be a little verbose.

Componentization

Tapestry is extremely component oriented and creating components is quick and easy. There is really nice integration of Javascript into components as well which ensure that multiple components of the same type on a page won't have javascript variable names that conflict.

Summary

Tapestry is a powerful framework which is well suited to creating lots of server-side components. There is a fairly steep learning curve (with mediocre documentation) to learning the way form handling works, but this is proportional to its power.

Of course, Scooby will probably not have many components on the server side, so Tapestry's main strength would be wasted here. However, it still should be considered a contender.