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pluginManagement: is an element that is seen along side plugins. Plugin Management contains plugin elements in much
the same way, except that rather than configuring plugin information for this particular project build, it is intended to configure project builds that inherit from this one. However, this only configures plugins that are actually referenced within
the plugins element in
the children.
The children have every right to override pluginManagement definitions.
Now : if I have this in my parent POM
<build>
<pluginManagement>
<plugins>
<plugin>
<artifactId>maven-dependency-plugin</artifactId>
<version>2.0</version>
<executions>
Some stuff for
the children
</execution>
</executions>
</plugin>
</plugins>
</pluginManagement>
</build>
and I run mvn help:effective-pom on
the parent project I get what I want, namely
the plugins part directly under build (the one doing
the work) remains empty.
Now if I do
the following :
<build>
<pluginManagement>
<plugins>
<plugin>
<artifactId>maven-dependency-plugin</artifactId>
<version>2.0</version>
<executions>
Some stuff for
the children
</execution>
</executions>
</plugin>
</plugins>
</pluginManagement>
<plugins>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>2.0.2</version>
<inherited>true</inherited>
<configuration>
<source>1.6</source>
<target>1.6</target>
</configuration>
</plugin>
</plugins>
</build>
mvn help:effective-pom I get again just what I want,
the plugins contains just what is declared and
the pluginManagement section is ignored.
BUT changing with
the following
<build>
<pluginManagement>
<plugins>
<plugin>
<artifactId>maven-dependency-plugin</artifactId>
<version>2.0</version>
<executions>
Some stuff for
the children
</execution>
</executions>
</plugin>
</plugins>
</pluginManagement>
<plugins>
<plugin>
<artifactId>maven-dependency-plugin</artifactId>
<version>2.0</version>
<inherited>false</inherited> <!-- this perticular config is NOT for kids... for parent only -->
<executions>
some stuff for adults only
</execution>
</executions>
</plugin>
</plugins>
</build>
and running mvn help:effective-pom
the stuff from pluginManagement section is added on top of what is declared already. as such :
<build>
<pluginManagement>
...
</pluginManagement>
<plugins>
<plugin>
<artifactId>maven-dependency-plugin</artifactId>
<version>2.0</version>
<inherited>false</inherited> <!-- this perticular config is NOT for kids... for parent only -->
<executions>
Some stuff for
the children
</execution>
<executions>
some stuff for adults only
</execution>
</executions>
</plugin>
</plugins>
</build>
Is there a way to exclude
the part for children from
the parent pom's section ? In effect what I want is for
the pluginManagement to behave exactly as
the documentation states, that is I want it to apply for children only but not for
the project in which it is declared.
As a corrolary, is there a way I can override
the parts from
the pluginManagement by declaring
the plugin in
the normal build section of a project ? whatever I try I get that
the section is added to executions but I cannot override one that exists already.
EDIT:
I never did find an acceptable solution for this and as such
the issue remains open. Closest solution was offered below and is currently
the accepted solution for this question until something better comes up. Right now there are three ways to achieve
the desired result (modulate plugin behaviour depending on where in
the inheritance hierarchy
the current POM is):
1 - using profiles, it will work but you must beware that profiles are not inherited, which is somewhat counter intuitive. They are (if activated) applied to
the POM where declared and then this generated POM is propagated down. As such
the only way to activate
the profile for child POM is specifically on
the command line (least I did not find another way). Property, file and other means of activation fail to activate
the POM because
the trigger is not in
the POM where
the profile is declared.
2 - (this is what I ended up doing) Declare
the plugin as not inherited in
the parent and re-declare (copy-paste)
the tidbit in every child where it is wanted. Not ideal but it is simple and it works.
3 - Split
the aggregation nature and parent nature of
the parent POM. Then since
the part that only applies to
the parent is in a different project it is now possible to use pluginManagement as firstly intended. However this means that a new artificial project must be created that does not contribute to
the end product but only serves
the could system. This is clear case of conceptual bleed. Also this only applies to my specific and is hard to generalize, so I abandoned efforts to try and make this work in favor of
the not-pretty but more contained cut and paste patch described in 2.
If anyone coming across this question has a better solution either because of my lack of knowledge of Maven or because
the tool evolved to allow this please post
the solution here for future reference.
Thank you all for your help :-)
