Re: Can plugins be extended?

> Plugins can't really be extended. What is most likely happening is that the metadata that tells plexus what to inject is not included in your plugin. There is a plugin/tool out there that supposedly allows you to extend plugins by merging the metadata, but I forget the name.
>
> -----Original Message-----
> From: walid joseph Gedeon [mailto:wgedeon@...]
> Sent: Tuesday, April 29, 2008 10:37 AM
> To: Maven Developers List
> Subject: Can plugins be extended?
>
> Hello all,
>    After failing to customize the compiler pluging (by passing
> <compileSourceRoots /> in the maven-compiler-plugin <configuration />); I've
> went onto trying to extend the maven-compiler-plugin CompileMojo to just set
> that variable.
>
> It looks like I've missed something: the injected parameters of the super
> classes are not being set (e.g. the parameter compilerId, or the component
> compilerManager in AbstractCompilerMojo are null).
> Is there a flag that enables injection of parameters in super classes? Or is
> the issue something else?
>
> Thanks :-)
> Walid.
>
> Note: a component definition maps the custom-compile goal to the <compile />
> phase.
>
> o====x maven-customcompile-plugin Mojo: x====o
> /**
> * @goal custom-compile
> * @phase compile
> * @requiresDependencyResolution runtime
> */
> public class CustomCompilerMojo extends CompilerMojo {
>    // ...
>
>    /**
>     * @parameter
>     */
>    private List<String> compileSourceRoots;
>
>    protected List<String> getCompileSourceRoots()
>    {
>        return compileSourceRoots;
>    }
>
>    public void execute() throws MojoExecutionException,
> CompilationFailureException
>    {
>        super.execute();
>    }
> }
>
> o====x Project POM: x====o
> <!-- ... -->
>   <build>
>     <plugins>
>       <plugin>
>         <groupId>fr.gedeon</groupId>
>         <artifactId>maven-customcompile-plugin</artifactId>
>         <extensions>true</extensions>
>         <configuration>
>           <compileSourceRoots>
>             <directory>Dev/src/java</directory>
>           </compileSourceRoots>
>         </configuration>
>       </plugin>
>     </plugins>
>   </build>
>
> o====x Partial Trace: x====o
> [DEBUG] Configuring mojo
> 'fr.gedeon:maven-customcompile-plugin:1.0-SNAPSHOT:custom-compile' -->
> [DEBUG]   (f) compileSourceRoots = [Dev/src/java]
> [DEBUG]   (f) project = org.apache.maven.project.MavenProject@82bcf39e
> [DEBUG] -- end configuration --
> [INFO] [bem:custom-compile]
> [DEBUG] Using compiler 'null'.
>  
>>       ^ this is from getLog().debug( "Using compiler '" + compilerId +
>>    
> "'." );
>  
>>         in AbstractCompilerMojo
>>    
> [INFO]
> ------------------------------------------------------------------------
> [ERROR] FATAL ERROR
> [INFO]
> ------------------------------------------------------------------------
> [INFO] null
> [INFO]
> ------------------------------------------------------------------------
> [DEBUG] Trace
> java.lang.NullPointerException
>         at
> org.apache.maven.plugin.AbstractCompilerMojo.execute(AbstractCompilerMojo.java:267)
>  
>>          ^ I suppose this is compiler = compilerManager.getCompiler(
>>    
> compilerId );
>  
>>            with compilerManager = null
>>    
>         at
> org.apache.maven.plugin.CompilerMojo.execute(CompilerMojo.java:114)
>         at
> org.apache.maven.plugin.CompileBemMojo.execute(CompileBemMojo.java:37)
> ...
>