Rack reloading loses associations

[Richard Fairhurst]

I use DataMapper (1) as part of a couple of Rack apps and generally find it works beautifully.

For development, I use Rack::Reloader, so that I can just change a source file and not have to bother restarting the Rack app. However, this has a habit of throwing an exception related to DM's associations. Typically I'll get something like this:

ArgumentError: +options[:field]+ entry :site_id does not map to a property in Marker

/usr/local/Cellar/ruby/2.0.0-p0/lib/ruby/gems/2.0.0/gems/dm-core-1.2.0/lib/dm-core/query.rb:805:in `block in assert_valid_fields'

/usr/local/Cellar/ruby/2.0.0-p0/lib/ruby/gems/2.0.0/gems/dm-core-1.2.0/lib/dm-core/query.rb:796:in `each'

/usr/local/Cellar/ruby/2.0.0-p0/lib/ruby/gems/2.0.0/gems/dm-core-1.2.0/lib/dm-core/query.rb:796:in `assert_valid_fields'

/usr/local/Cellar/ruby/2.0.0-p0/lib/ruby/gems/2.0.0/gems/dm-aggregates-1.2.0/lib/dm-aggregates/query.rb:23:in `assert_valid_fields_with_operator'

/usr/local/Cellar/ruby/2.0.0-p0/lib/ruby/gems/2.0.0/gems/dm-core-1.2.0/lib/dm-core/query.rb:768:in `block in assert_valid_options'

/usr/local/Cellar/ruby/2.0.0-p0/lib/ruby/gems/2.0.0/gems/dm-core-1.2.0/lib/dm-core/query.rb:766:in `each'

/usr/local/Cellar/ruby/2.0.0-p0/lib/ruby/gems/2.0.0/gems/dm-core-1.2.0/lib/dm-core/query.rb:766:in `assert_valid_options'

/usr/local/Cellar/ruby/2.0.0-p0/lib/ruby/gems/2.0.0/gems/dm-core-1.2.0/lib/dm-core/query.rb:363:in `update'

/usr/local/Cellar/ruby/2.0.0-p0/lib/ruby/gems/2.0.0/gems/dm-core-1.2.0/lib/dm-core/associations/relationship.rb:158:in `block in query_for'

/usr/local/Cellar/ruby/2.0.0-p0/lib/ruby/gems/2.0.0/gems/dm-core-1.2.0/lib/dm-core/repository.rb:114:in `scope'

/usr/local/Cellar/ruby/2.0.0-p0/lib/ruby/gems/2.0.0/gems/dm-core-1.2.0/lib/dm-core/associations/relationship.rb:153:in `query_for'

/usr/local/Cellar/ruby/2.0.0-p0/lib/ruby/gems/2.0.0/gems/dm-core-1.2.0/lib/dm-core/associations/relationship.rb:308:in `eager_load'

/usr/local/Cellar/ruby/2.0.0-p0/lib/ruby/gems/2.0.0/gems/dm-core-1.2.0/lib/dm-core/collection.rb:1477:in `delegate_to_relationship'

/usr/local/Cellar/ruby/2.0.0-p0/lib/ruby/gems/2.0.0/gems/dm-core-1.2.0/lib/dm-core/collection.rb:1446:in `method_missing'

/Users/richard/Code/avanti_kite/model/marker.rb:154:in `bbox_search'

The association is this:

belongs_to :site, :required => false

and it's being called like this in marker.rb/154:

user.organisation.sites.markers(filter)

but this isn't a one-off - it happens in my other apps too. It always happens on the first refresh after Rack has reloaded the app.

It's not fatal - I can always manually restart the app - but it's a PITA. Any thoughts?

Richard