content/apt/examples/injecting-properties-via-settings.apt

  ---
  Example: Injecting POM Properties via Settings.xml
  ---
  John Casey
  ---
  2006-04-20
  ---

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Example: Injecting POM Properties via Settings.xml

* Impetus

  You have a plugin parameter that should contain a user-specific value. This
  parameter has a common format (relative directory structure), but depends on
  knowing the directory of the installed application or something.

* Plugin Configuration

+---+
<project>
  [...]
  <build>
    <plugins>
      <plugin>
        <groupId>org.myproject.plugins</groupId>
        <artifactId>my-cool-maven-plugin</artifactId>
        <version>1.0</version>
        <configuration>
          <deploymentDirectory>${application-home}/deploy</deploymentDirectory>
        </configuration>
      </plugin>
    </plugins>
  </build>
+---+

* <<<settings.xml>>>

+---+
<settings>
  [...]
  <profiles>
    <profile>
      <id>inject-application-home</id>
      <properties>
        <application-home>/path/to/application</application-home>
      </properties>
    </profile>
  </profiles>

  <activeProfiles>
    <activeProfile>inject-application-home</activeProfile>
  </activeProfiles>
</settings>
+---+

* Explanation

  When Maven loads the project's POM, it will pickup the activated profiles from 
  the <<<activeProfiles>>> section of the <<<settings.xml>>> file, and inject the
  properties declared within the profile. When the POM is interpolated, the 
  <<<application-home>>> property will already have been injected, so will allow
  the plugin's parameter value to be resolved.