Basic Dovetail DB Questions

[frankspeak]

Hi,

I really like the scope of DoveTailDB; it appears that it may prove
one of the fastest way to develop v simple RIAs. I'm beginning work on
such a scalable reverse ajax project and have some basic questions:

- What is the status of the project? How close is it to beta/first
release?
- What is the reverse AJAX implementation: Does it support Comet/
piggyback or only client polling?
- Where is the source code and/or javadocs? How can I for instance,
hook in my own Java classes to run on the server, to populate the db
with external dynamic data?
- Do you have a distribution I can integrate with Tomcat/Jetty etc.
directly (i.e. without the third-party components already integrated
in dovetaildb.jar)?
- Are there any examples/recommendations wrt Javascript libraries to
integrate with (I'm a big jquery fan)?

Thx in advance,
Frank.

[Phil]

Hi Frank!

> - What is the status of the project? How close is it to beta/first
> release?

Sadly, it's not very mature at the moment. Some large-ish changes are
on the way that should provide a relatively complete and stable
baseline to beta -- I'm hoping to get this out in August/September.
If you decide to wait, I'd still like to hear what features/
capabilities are important to you.

> - What is the reverse AJAX implementation: Does it support Comet/
> piggyback or only client polling?

Comet (long-lived HTTP requests) is supported. The javascript client
library uses dynamic script tags to make requests from the server
(called JSONP, right?), and if &comet_timeout= is specified, that
script won't actually return until data is available (or the timeout
passes). Frankly, I'm not much of a web developer, so if someone has
guidance on how all this should work and what methods should be
supported, I'd love to hear it. One problem that I have presently is
that long-lived dynamic script tags tend to make browsers look like
they're perpetually loading the page.

> - Where is the source code and/or javadocs? How can I for instance,
> hook in my own Java classes to run on the server, to populate the db
> with external dynamic data?

On Google code:
http://code.google.com/p/dovetaildb/source/browse/

For batch loading, a common (but perhaps less performant) idiom is to
create a server-side javascript function to load batches of a few
hundred records at a time.

> - Do you have a distribution I can integrate with Tomcat/Jetty etc.
> directly (i.e. without the third-party components already integrated
> in dovetaildb.jar)?

Yes, with a little java knowledge, though I haven't actually tried to
run it this way -- dovetaildb.servlet.StdServlet is the servlet that
actually runs. There's a constructor that takes a properties object,
which corresponds to the the properties file you setup when installing
the standalone server. One potential gotcha is the comet
implementation, because I don't think there's a standard for doing
this that's portable across servlet containers.

> - Are there any examples/recommendations wrt Javascript libraries to
> integrate with (I'm a big jquery fan)?

I'd love to have some, but sadly have little experience with what's
out there. Looking at jQuery, I think you could set something up with
jQuery.getScript() -- turn on firebug network tracing with the default
dovetail.js implementation to see what the URLs look like -- I think
you'll find it pretty darn intuitive. If you get something working,
it would be awesome to see a quick summary of how to do it posted
here.

Hope this helps. Cheers,
Phil

[frankspeak]

Thanks Phil!