Question

I’m fairly new to ant, and I’ve seen uncle Bob’s “extract until you drop” episode.

As a result I try to define ant-targets as small as possibly possible, so you can see exactly the essence of the target, and no more. For more details, you have to refer to sub-targets.

Whether that’s good or bad style is a different debate (or a flame-war maybe).

Therefore, I was creating a build script that, in pseudo-code, would look like this:

build =
   compile
   instrument if coverage

The coverage task is split into subtargets, too:

coverage:
   create-coverage-dirs
   call-cobertura

EDIT- I want to express that coverage sub-targets should not be run.

But… I’m having a hard time expressing this ‘cleanly’ in ant-ese.

Assuming that I can use the depends attribute to indicate … inter-target dependencies, I got to something like this:

<target name="build" depends="compile, coverage"/>

<target name="compile"> .... </target>

<target name="coverage" depends="
       create-coverage-dirs, 
       taskdef-cobertura"
 if="build.with.coverage">

  <cobertura-instrument ...> ... </cobertura-instrument>

</target>

<target name="create-coverage-dirs">
  ...    
</target>

<target name="taskdef-cobertura">
  ...
</target>

Whow this looked nice!

Only it seemed that, when executing, the coverage task was duefully omitted, but it’s sub-tasks were still executed when build.with.coverage was false!

>ant -v compile
Build sequence for target(s) `build' is 
  [compile, create-coverage-dirs, taskdef-    cobertura, coverage, build]
Complete build sequence is 
  [compile, create-coverage-dirs, taskdef-cobertura, coverage,    build, ]

I can put an if attribute in every coverage sub-task, but that doesn’t seem clean to me.

So here’s the question:

1. Is my ant-ese a horrible dialect? Am I ‘making ant into make’?
2. Should if be used this way, or is there an if-and-recurse kind-of attribute?

Answer 1

I would not use a property at all in this case, but rely solely on depends (which seems more natural to me for this task):

<target name="build" depends="compile, coverage"/>

<target name="compile"> ...

<target name="coverage" 
        depends="compile, instrument,
                 create-coverage-dirs, taskdef-cobertura"> ...