About the 'other goal':
4 lists of configuration are located in the registry (~/.m2/archetype.xml);
They contain the groupIds, the repositories, the languages and the filtereds:
- groupIds are used for prompting the user
- repositories are used to retrieve the maven metadatas to propose the archetype and version selection
- languages are directory names that contains 'packaged' sources and used during the create-from-project
- filtered are file extensions that are used to separate velocity templates from binary files and used during create-from-project
Some goals are provided to administer the registry file.
There is add-Xs, remove-Xs, show-Xs for each of the 4 lists in the registry.
Of course one can still edit that file by hands
These mojos exist since late april but not documented
About the settings reading,
When i started, i used the repositories defined in the project, thinking the repositories defined in profiles in settings would be used. But they weren't.
I also desired to have the settings holds archetype groups like it holds the plugins groups. but it was too much change for the plugin only archetypeng was at this time.
I then decided to create the registry file to contains these 2 configuration lists. And when i wrote create-from-project, i used the registry to hold 2 more configuration lists. Hence the other goals.