The DataMapper module has some quirks, mainly:
For models that have the “storage_name” explicitly defined, the “has n, :through => Resource” relation doesn't work well. Don't use models, that have non-standard table names, or create the habtm resource by hand (check the test application)
Because DataMapper uses a module instead of a superclass, you have to add the appropriate scaffolding_extensions modules by hand. The simplest way is to use the `add_scaffolding_methods` method in your controller, or initialization script:
class Dm < Merb::Controller
add_scaffolding_methods [DmOfficer, DmMeeting, DmEmployee, DmGroup, DmPosition] scaffold DmOfficer scaffold DmMeeting scaffold_all_models :only =>[DmEmployee, DmGroup, DmPosition]
You need dm-core, dm-validations, dm-transactions to use scaffolding extensions with datamapper. You also need do_sqlite3 in order to run the test_suite for scaffolding_extensions with datamapper.