Hi guys,

I get the following stack trace, I'm pretty sure my model is ok although I haven't finished the website yet and the
model is very complex (lots of STI, polymorphism etc) so there _could_ be an issue with my modelling.

Anyone seen this before? Ideas?

Cheers,
//matt

/usr/lib/ruby/gems/1.8/gems/activerecord-2.2.2/lib/active_record/reflection.rb:244:in `source_reflection': You have
a nil object when you didn't expect it! (NoMethodError)
The error occurred while evaluating nil.klass
	from /usr/lib/ruby/gems/1.8/gems/activerecord-2.2.2/lib/active_record/reflection.rb:244:in `collect'
	from /usr/lib/ruby/gems/1.8/gems/activerecord-2.2.2/lib/active_record/reflection.rb:244:in `source_reflection'
	from /usr/lib/ruby/gems/1.8/gems/activerecord-2.2.2/lib/active_record/reflection.rb:303:in `derive_class_name'
	from /usr/lib/ruby/gems/1.8/gems/activerecord-2.2.2/lib/active_record/reflection.rb:107:in `class_name'
	from /usr/lib/ruby/gems/1.8/gems/railroad-0.5.0/lib/railroad/models_diagram.rb:134:in `process_association'
	from /usr/lib/ruby/gems/1.8/gems/railroad-0.5.0/lib/railroad/models_diagram.rb:102:in `process_class'
	from /usr/lib/ruby/gems/1.8/gems/railroad-0.5.0/lib/railroad/models_diagram.rb:101:in `each'
	from /usr/lib/ruby/gems/1.8/gems/railroad-0.5.0/lib/railroad/models_diagram.rb:101:in `process_class'
	from /usr/lib/ruby/gems/1.8/gems/railroad-0.5.0/lib/railroad/models_diagram.rb:27:in `generate'
	from /usr/lib/ruby/gems/1.8/gems/railroad-0.5.0/lib/railroad/models_diagram.rb:26:in `each'
	from /usr/lib/ruby/gems/1.8/gems/railroad-0.5.0/lib/railroad/models_diagram.rb:26:in `generate'
	from /usr/lib/ruby/gems/1.8/gems/railroad-0.5.0/bin/railroad:47
	from /usr/bin/railroad:19:in `load'
	from /usr/bin/railroad:19

Date: 2009-04-10 03:23
Sender: François Montel

Likely a problem with your associations. This error is triggered
when it can't find the associated class for a model. I ran into
the same problem and after careful checking, found an error in
my models.

What I did was to take all my models out of the model folder,
and then put them in one by one, running the railroad command
each time. That allowed me to find the model that was triggering
the error when then alerted me to the fact that I had an error
in my associations.

Date: 2009-03-28 20:40
Sender: Bryan Woods

I'm having this very same issue, did you find a fix?
It's good to see you're using 2.2.2, since I was originally worried
this error was an upgrade to 2.3.2 problem.
I also am dealing with relatively complex polymorphism in my
models, so I'm very intrigued by any workaround you might have
found.

Bryan