Gant is a Groovy-based framework for scripting Ant tasks.

Gant is a lightweight wrapper around Groovy's AntBuilder that allows Ant tasks to be scripted using Groovy. This means it can be used as a replacement for Ant: instead of specifying things using XML, they are specified with Groovy.

A Gant file is a specification of a set of targets plus other bits and pieces of Groovy code. Thus a Gant specification is of a set of targets just as an Ant specification is. Each target creates a closure in the binding so that it can be called as a function from other targets. This means that dependencies between targets are programmed as function calls.

Gant has a number of predefined objects, for example ant, includeTargets and includeTool. ant refers to a pre-constructed GantBuilder object. includeTargets is the object that controls the inclusion of ready-made targets, for example gant.targets.Clean. includeTool is the object that controls the inclusion of ready-made tools, for example gant.tools.Execute.

Here is an example Gant script:

includeTargets << gant.targets.Clean
cleanPattern << [ '**/*~' ,  '**/*.bak' ]
cleanDirectory << 'build'

target ( 'default' : 'The default target.' ) {
  println ( 'Default' )
  depends ( clean )
  echo ( message : 'A default message from Ant.' )
  otherStuff ( )
}

target ( otherStuff : 'Other stuff' ) {
  println ( 'OtherStuff' )
  echo ( message : 'Another message from Ant.' )
  clean ( )
}
      

The function depends takes a list of targets and 'executes' them if and only if they have not previously been executed. This means that dependencies can be handled far more flexibly than they can in Ant, leading to simpler target structures.


Russel Winder
Last modified: 2010-04-05T08:30+01:00