can't reference module in /lib/foo

rubyonrails-talk
1

I tried creating a module in /lib/my_foo/foo_bar.rb called module MyFoo::FooBar. Inside that module I defined a method getFoo(). I modified application.rb and added the line config.autoload_paths += %W(#{Rails.root}/lib).

When I tried to access MyFoo::FooBar.getFoo() in my controller I got the following error: undefined method `getFoo' for MyFoo::FooBar:Module

I realized that I didn't make getFoo a class method so I tried changing the method definition to MyFoo::FooBar.getFoo(), but then I got the following error:

syntax error, unexpected '.', expecting '\n' or ';'     def MyFoo::FooBar.getFoo()

I then tried changing the method definition to self.getFoo() and everything works fine. I also tried moving foo_bar.rb directly into /lib, changed the module name to FooBar and the method definition to FooBar.getFoo() and that also worked. My question is why? I assume I just don't have the correct syntax for specifying the module name when it's in one or more sub-directories off of /lib instead of directly in /lib, but I can't figure out what the correct syntax should be.

I'm fine with using "self", but I'd like to understand what I'm doing wrong.

2

I tried creating a module in /lib/my_foo/foo_bar.rb called module MyFoo::FooBar. Inside that module I defined a method getFoo(). I modified application.rb and added the line config.autoload_paths += %W(#{Rails.root}/lib).

When I tried to access MyFoo::FooBar.getFoo() in my controller I got the following error: undefined method `getFoo' for MyFoo::FooBar:Module

I realized that I didn't make getFoo a class method so I tried changing the method definition to MyFoo::FooBar.getFoo(), but then I got the following error:

syntax error, unexpected '.', expecting '\n' or ';' def MyFoo::FooBar.getFoo()

I then tried changing the method definition to self.getFoo() and everything works fine. I also tried moving foo_bar.rb directly into /lib, changed the module name to FooBar and the method definition to FooBar.getFoo() and that also worked. My question is why? I assume I just don't have the correct syntax for specifying the module name when it's in one or more sub-directories off of /lib instead of directly in /lib, but I can't figure out what the correct syntax should be.

I'm fine with using "self", but I'd like to understand what I'm doing wrong.

You're finding the module fine (if you weren't the error you'd get something along the lines of uninitialized constant MyFoo), you're just not calling the method right.

given

module Foo   def bar   end end

Then you can't do Foo.bar, it just doesn't work that way (it's like trying to call a classes instance method on the class itself. Doing def self.bar or def Foo.bar makes it a singleton method, so you can then do Foo.bar

with a module nested in another you can't write

module Foo   module Bar     def Foo::Bar.foo     end   end end

it's just not syntactically valid. You can write

module Foo   module Bar     def Bar.foo     end   end end

which does create Foo::Bar.foo

Fred