`const_missing'：未初始化的常量（NameError）

Question

Every time I try to run any class from my rails 2.2 app's lib directory using "script/runner -e production ClassName.run" I get the following error:

/usr/lib/ruby/gems/1.8/gems/rails-2.2.2/lib/commands/runner.rb:47:  
/usr/lib/ruby/gems/1.8/gems/activesupport-2.2.2/lib/active_support/dependencies.rb:89:in `const_missing': uninitialized constant ClassName (NameError)"

For some reason I don't get this error when I run it as test instead of production , and everything works fine.

O yeah run is a class method ie def self.run.... end

Any suggestions?

Answer 1

That error occurs when ruby can't find a Class or Module. I'd start out by:

1. Checking gem dependencies (are they same for all environments?)
2. Search your code for anything that defines ClassName, particularly Modules, Classes and plugins.
3. disable each of your plugins in dev, does any plugin suddenly cause that error?
4. if the code is in a lib add the lib require statement to your production.rb to force the lib to be loaded in production.

Hope that helps.

update Just to summarise the comments it was option 4.

Unless you only want to load the lib in production you should think about making sure all environments load the lib by doing one of the following:

1. Create a rails initializer (a.rb file under config/initializers) with the require in it
2. Add the path to the lib in config/environment.rb by enabling and modifying the config.load_paths variable.

Answer 2

I had multiple class definition(all STI classes) on the same file. and when I separated the definition into their respective files, It works