Re: [pde-build-dev] Eclipse Builds and Maven 2.x

[Jeff McAffer <Jeff_McAffer@xxxxxxxxxx>]

Wendell Beckwith wrote on 06/08/2006 06:07:28 PM:
> On 6/7/06, Jeff McAffer <Jeff_McAffer@xxxxxxxxxx>
wrote:
> 
> To me the best place is to write an example following ideal Maven
> setup (given what we have to start with in Eclipse in terms of 
> source layout etc) and see what that is.  For us we understand
the 
> words but not the real meaning.  I suspect also that this will
> uncover some issues.   Essentially this would have examples at
both 
> ends of the spectrum.
> 
WB> This sounds fine to me.  I will start with a hello world plugin
> project using the PDE template and rework the project layout for 
> maven projects.  

Ok.  In the end we'll have to get to a point
of building and packaging a full RCP app for multiple platforms etc.  Dealing
with SWT and all the zipping, gathering, packaging issues.

> Before we went the RCP route for some of our
work 
> the default eclipse project layout was mostly maven compatible.  
> Actually I probably could have made it work with out changing the
> eclipse layout, but if you go the maven route and use their layout
> then a lot of plugin configuration is completely wiped out since 
> they will assume the default layout and everything just works. 

I don't believe that we will be able to mandate that
anyone change their project layout.  80% of the plugins I see are
standard src folder with random other files included in various places.
 A few have very custom source layout driven by real needs.  In
the former case it would be better to adapt the tool to the convention
rather than force everyone to change.  For the latter the source layout
is there for a reason and the teams would likely not be keen on changing.
 

> On a different frontthe dependency resolution
issue seems central in
> as much as that, for both Maven and PDE, it drives the show.  As
was
> mentioned before, we have (or can quickly make) a standalone OSGi
> resolver JAR that should be good for this usecase.  Integrating
that
> and prototyping a mechanism for driving Maven via manifests seems
> like a good place to start.
> 
WB> This is the one that is going to generate the most sleepless nights
> for me as this is where maven itself will have to be enhanced and
 
> "use the source  Luke" is still the appropriate  SOP
(standard 
> operating procedure), even though I  will freely admit their
> documentation improved a whole lot after 2.0 was released.  Yet
and 
> still there are holes that can only be grokked by reading the code.
> 
> As for what is on the table, we clearly cannot destablize the build
> system.  It does seem unlikely that we would pitch PDE build
and use
> Maven in the 3.3 timeframe.  Seems like alot of risk.  However,
one 
> has to have goals and then make baby steps towards them.  
> Understanding what it would mean to jump all the way to the other
> end of the spectrum is one of those baby steps. 
> 
> Jeff 
> 
> ps., I hear the kool-aid is Grape.  Is that right?
> 
WB> I share your concerns because in general I'm a pessimist but I'm
> optimistic that if the dependency resolution issue is handled to 
> every one's satisfaction then the rest will come quickly. 

I agree but am not particularly optimistic at this
point. One downside is that Maven uses the dependency info to download
prereqs.  This is cool but as it is, maven dependecies are on explicit
JARs.  This means that reading a POM, you know exactly what to download.
 if you go to package dependencies, you need all the metadata (to
see who supplies what) then resolve it and walk the resultant wirings and
fetch prereqs.  Of course, you could start with the ones you have
locally already and then just fetch the things that are missing...  

In the end this turns into a provisioning problem.
 Saying "I want to build X, what else do I need so I can compile?"
is very similar to saying "I want to install X, what else do I need
so it will run?"

> FYI, It took a while but I got my company to
join the Eclipse 
> Foundation effective 05/30/06 and as part of the welcome kit I got
> the bill for it all today.  :)

Awesome.  Congratulations, thank you and welcome.