Question

I’m trying to use a code generator inside a buildr-based java project. I would like to…

• call the generator
• compile the generated classes, package them
• eclipse to see the generated stuff (i.e. have the .classpath contain those sources)

I’ve spend lots of time googling around for a complete example, but to no avail. the example here: https://cwiki.apache.org/confluence/display/BUILDR/How+to+generate+sources+before+compilation

gives be plenty of errors. this is what I’ve tried:

 define 'generator' do
    compile.with ALL_COMMON_MODULES
  end
  define 'extras' do
    p 'calling generator..'
    Java.classpath << ALL_COMMON_MODULES
    Java.classpath << projects('generator')
    Java.org.foo.generator.Main.main(['../modules/daos', 'target/generated-sources'])
    sources = FileList[_("src/main/jeannie/*.*")]
    generate = file(_("target/generated-sources") => sources).to_s do |dir|
      puts 'generating...'
      mkdir_p dir.to_s # ensure directory is created
    end
    compile.from generate
  end

gives me an error like this:

RuntimeError: Circular dependency detected: TOP ...

so I’m obviously doing something very very wrong. I’d be very glad to see a working example or project that uses code generation.

Answer 1

I finally got it working with help from the buildr mailinglist. for anyone interested: The example mentioned here contains a problem. this:

compile.from generate

should be:

compile.from generate.to_s

Now it works beautifully! buildr also automatically extends the .classpath for eclipse (and idea, in case you use that) if ‘compile.from’ points to another location.