[kepler-dev] downloadable actors

[Xiaowen Xin]

Hi Everyone,

Something that we'd like to implement as part of SPA/Kepler is an Actor
Repository with some actors that we don't include as part of the normal
distribution.  So people can go there, and download additional actors.

What do you all think is a good mechanism for doing this?

More specifically, we could simply distribute a tarball that includes
the actor source code, class file, and xml configuration file, ask the
user to unpackage it in a certain directory that's in her classpath. 
Then, ask the user to import that configuration file.  After doing this,
the actor will get inserted into "~/.ptolemyII/user library.xml", so the
next time the user runs SPA/Kepler, the system will automatically load
the actor.

However, this method seems to be quite complicated from a user
perspective.  It would be ideal to simply have the users download one
file, put it in a certain directory, and the system automatically loads
it at startup.

Dave and I have been thinking that we could potentially distribute these
actors as .jar files, that have the source, class file, and
configuration file all within.  The user could put this jar file in
~/.ptolemyII/ and the system should automatically load it at startup.

On the downside, the implementation of this might be somewhat involved. 
We would need to execute something that finds all jar files in
~/.ptolemyII/ and create our own classloader that has the jar files in
its classpath.  Then we would need to somehow add the newly found actors
to the treeview at the lefthand side.

Do you all know of any built-in mechanisms that can help do this?

Thanks,
Xiaowen