My gut says: There be Dragons. If people want to use Maven, let them.
People come to buildr to get away from a lot of that stuff. Just
because something is possible, doesn't mean you should do it.
That said, it would be funny if Buildr ended up being a better Maven
than Maven itself. Still, I'd wait and see what the Maven 3 team comes
up with before looking in to integrations too closely. The solutions
will likely be cleaner for the reasons you list below.
On 04/26/2010 08:44 AM, Daniel Spiewak wrote:
Over the weekend, I spent a little time dredging through Maven's
highly-diffuse documentation and I have come to the conclusion that we could
actually add support for running Maven plugins (mojos). In theory, this
integration could be fairly tight, making it possible to configure a Maven
plugin in the scope of a particular project and then use the relevant goals
as plain-old Rake tasks (e.g. test.enhance('surefire:report'), to pick a
really pointless example). There are a couple of problems though.
1. Maven2 was designed before Java 5, and so Mojos use non-standard
doclet annotations (parsed with Qdox) to define goals, parameters, etc.
This is tricky, because I *think* this means that Maven has to actually
download a plugin's source in order to execute it, but documentation on this
point seems to be sparing. Anyone care to shed some light?
2. The Mojo API seems to have *scads* of undocumented features (like
gaining access to a MavenProject instance). A lot of these are mentioned
in passing on the wiki, but I'm not confident that we could track them all
down, meaning we would have holes and incompatibilities in our Maven Plugin
support (we wouldn't be able to support some plugins, and we wouldn't really
know which ones). Undocumented behavior sucks.
3. At the very least, we need to be able to define our own implementation
of the MavenProject class, and this is potentially the biggest roadblock of
them all. In a nutshell, we need to extend MavenProject, implementing all
(or as many as possible) of its methods in terms of the Buildr API.
Unfortunately, RJB doesn't seem to allow for extension of Java classes. I
suppose we could extend MavenProject in Java code and somehow sneak
callbacks across the barrier, but this seems both ugly and disaster-prone.
JRuby *does* allow for the extension of Java classes, so we could still
conceivably do this, but it would mean that Maven Plugin support would not
be available when running under MRI.
Any thoughts? Does anyone else think this is worth pursuing? (with the
knowledge that my spare time is...sparing, so this won't get done quickly)
Daniel
