On Saturday 30 September 2006 08:27, Jeff McAffer wrote:
> - Built bundles have a manifest.mf that fully specifies what the bundle
> can supply and what it needs. If Maven could read the manifest directly,
> you would not need a POM for the bundle when buliding it. This in turn
> would allow people to build against products and other delivered software
> which does not live in an accessible maven repo.
Huh? Do you think that jakarta-commons people would want to bother about
package dependencies, instead of their current "jar dependencies" approach.
I don't. It doesn't bring them anything useful at all. At the most, we could
hope for is;
1. Maven maps in what it can without people's active help.
2. OSGi interested parties assist in 'tuning' the Manifest creation.
Requiring that projects has to maintain the Manifest down to the last dot,
ain't very likely to happen.
> - At development time, some people prefer to specify their dependencies in
> manifests rather than poms. Having Maven read dependency info from the
> manifest would eliminate the need to duplicate that information.
"Some people" ;o)
Have heard that argument for long now, but it seems to me being more a view
enforced onto "some" by Eclipse ways of doing things. If Eclipse had chosen
another approach X, then the sentence above would have been "some people
prefer X".
Never the less.
The manifest is not a strong candidate for describing dependencies, and that
would perhaps been more clear if you worked outside the Eclipse world. Often
cited reasons of not using it;
- Doesn't haven any kind of "scope", such as Test, Develop and Production.
- Makes it harder to generate several outputs from the same codebase
(although Maven requires a similar limitation).
- Doesn't allow additional build-time meta-info.
Manifest specifies "Bundle-ClassPath: abc.jar", but what jar is that and how
is that obtained?? For the 'click-myself-to-death' systems it is up to the
user to manually 'fix' that, typically by committing jar files into CVS/SVN
(a discouraged practice at ASF), and YET Eclipse store information about that
in its own files, which I think proves the suitability of the manifest as a
build co-ordination tool is over-rated, and time for the Eclipse folks to
admit it ;o)
Cheers
Niclas
