The Myrmidon-Ant1 Compatibility layer works by reusing most of the Ant 1 code, with tasks and datatypes being prefixed with "ant1." in build files. Almost all of the main Ant 1 tree is included in the compatibility layer antlib. To insulate from changes in the Ant 1 tree, Ant 1 class files are extracted from a jar, rather than being compiled from scratch.

Here's how it works: The first time an Ant 1 task is encountered, an Ant 1 project is created, and stored in the TaskContext under the name "ant1.project". The Ant 1 versions of Task and Project have been extended, overriding core behaviour, with Myrmidon-specific behaviour.

The updated version of Task implements Configurable, receiving it's complete Task Model, and actually setting/adding/creating attributes with the help of the IntrospectionHelper. This process is designed to mimic the Ant 1 configuration policy, although not all of the subtle variations of configuration present in Ant 1 are handled.

The updated version of Project will provide hooks into the Myrmidon TaskContext, such as:

• logging (done)
• properties (done)
• references (not yet done)
• Task defined by <taskdef> (done)

So at present, properties declared in Ant 2 tasks are available to all Ant 1 tasks, and vice-versa. However, while a <ant1.path> reference works fine in other <ant1.XXX> tasks, it's not visible to Ant 2 tasks in the same build, and vice-versa.

The <taskdef> task works ok, registering the task with the TypeManager using the "ant1." prefix. Only a couple of DataTypes (Path and Patternset) are working as top-level types, but this should be just a matter of adding references to the Ant 1 version of TypeInstanceTask in the descriptor.

The TransformingProjectBuilder (which is now the default builder for files of type ".xml", applies a transformation stylesheet to the file, prefixing select tasks (all at present) with "ant.". If a version attribute is encountered, the file is not transformed

Using Ant 1 tasks in a Myrmidon build file

If you have a Myrmidon build file (eg with version="2.0" on the project element, you can use Ant 1 tasks and datatypes by using the "ant1." suffix on the regular element name. Virtually all tasks and datatypes from Ant 1.4.1 are available in this way. When declaring a new task using the <ant1.taskdef> task, don't prepend "ant1." to the taskname. This will be done automatically by the taskdef task. However, you will need to use the "ant1." prefix in all uses of that task.

Using an existing Ant 1 build file

Myrmidon will automatically handle Ant 1 build files using the Ant 1 Compatibility layer. So, using an Ant 1 build file with Myrmidon should be as simple as: [myrmidon-command] -f ant1-build-file.xml This works as follows: When Myrmidon encounters a ".xml" build file which does not have a version attribute on the top-level project element, it assumes that it is an Ant 1 build file. So all tasks are interpreted as though they are prefixed with the "ant." name prefix.

Before building the Ant 1 Compatibility layer, you need to build Myrmidon, running the dist-lite target of the main build. See the build instructions for more details.

To build the compatibility layer, simply execute:

ant -f ant1compat.xml

from within the root directory of the Myrmidon source tree.