Can parent poms receive properties from children?

Can something in the parent pom take a value declared in the child pom?

Specifically I want to do something like this.

Parent:

<scm>
    <connection>scm:git:[email protected]:team/${git.repo}.git</connection>
    <developerConnection>scm:git:[email protected]:team/${git.repo}.git</developerConnection>
    <url>http://github.corp.com/team/${git.repo}</url>
</scm>

Child:

<properties>
    <git.repo>Foo</git.repo>
</properties>

Ideally the git.repo property is explicitly not set in the parent, such that the child must override either it, or override the scm section fully.

Solution

Can something in the parent pom take a value declared in the child pom?

Yes. In order to have a valid parent POM, however, I suggest providing a default/dummy value for ${git.repo} in the parent.

To deal with cases where a child POM does not override (i.e. redefine) ${git.repo} you could introduce a profile in the parent like so:

<profiles>
  <profile>
    <id>property-not-redefined</id>
    <activation>
      <activeByDefault>false</activeByDefault>
      <property>
        <name>git.repo</name>
        <value>your-default-value</value>
      </property>
    </activation>
    <build>
      <plugins>
        <!-- do something here -->
      </plugins>
    </build>
  </profile>
</profiles>

This profile becomes active when the git.repo property still has the default value.