------
 Selector Scripts
 ------
 Stephen Connolly
 ------
 2009-10-20
 ------

 ~~ Licensed to the Apache Software Foundation (ASF) under one
 ~~ or more contributor license agreements.  See the NOTICE file
 ~~ distributed with this work for additional information
 ~~ regarding copyright ownership.  The ASF licenses this file
 ~~ to you under the Apache License, Version 2.0 (the
 ~~ "License"); you may not use this file except in compliance
 ~~ with the License.  You may obtain a copy of the License at
 ~~
 ~~   http://www.apache.org/licenses/LICENSE-2.0
 ~~
 ~~ Unless required by applicable law or agreed to in writing,
 ~~ software distributed under the License is distributed on an
 ~~ "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 ~~ KIND, either express or implied.  See the License for the
 ~~ specific language governing permissions and limitations
 ~~ under the License.

 ~~ NOTE: For help with the syntax of this file, see:
 ~~ http://maven.apache.org/doxia/references/apt-format.html

Selector Scripts
 
  Starting with plugin version 1.5, a custom script can be used to skip individual projects based on 
  whatever critria are expressed in the script as illustrated in the following example. Assume the 
  following directory structure:

+------------------
./
+- pom.xml
+- src/
   +- it/
      +- settings.xml
      +- conditional-it/
         +- pom.xml
         +- check-assumptions.bsh
         +- src/
+------------------

  The plugin configuration for this example would look like this:

+------------------
<project>
  ...
  <build>
    <plugins>
      <plugin>
        <artifactId>maven-invoker-plugin</artifactId>
        <version>${project.version}</version>
        <configuration>
          <projectsDirectory>src/it</projectsDirectory>
          <cloneProjectsTo>\${project.build.directory}/it</cloneProjectsTo>
          <pomIncludes>
            <pomInclude>*/pom.xml</pomInclude>
          </pomIncludes>
          <settingsFile>src/it/settings.xml</settingsFile>
          <localRepositoryPath>\${project.build.directory}/local-repo</localRepositoryPath>
          <selectorScript>check-assumptions.bsh</selectorScript>
        </configuration>
        <executions>
          <execution>
            <id>integration-test</id>
            <goals>
              <goal>install</goal>
              <goal>run</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>
  ...
</project>
+------------------

  If the check-assumptions.bsh script returns <<<true>>> or does not return a value, then the project will be executed.

  If the script returns any value other than <<<true>>>, then the project will be executed.

  If the script throws an exception, then the project will be marked as being in ERROR.