Module variable with 'require' problem

[inteloide]

Hello !

I'm developping plugins that become bigger and bigger. Therefore, to make code more readable, I split it in different files, using function 'require'.
I'm following Thomthom's golden rules , by using module and then module variable.
But when in file linked by 'require' I cannot access to module variable anymore !

Here is a simplified sample to explain :

Here is the first file (called 'A.rb'):
[pre:1oz1zcpi]

require 'sketchup.rb'
module M
	class A
		def initialize
			@@var="123"
		end
		def show
			UI.messagebox(@@var)
			change
			UI.messagebox(@@var)
		end
		require 'B.rb'
	end
	
	Mod=A.new
end #module

if !file_loaded?(__FILE__) then
	m = UI.menu("Plugins").add_item("Test")  {M;;Mod.show  }
end

file_loaded(__FILE__)

[/pre:1oz1zcpi]

And here is the second file ('B.rb'):

def change
	@@var="321"
end

If you run the code, you will have 2 message boxes with '123'. As change has not been called.
Now, just replace require 'B.rb' by the code of B.rb (='def change....') and it works ! You have two mesaage boxes, one with '123' the other '321'.
Actually, @@var is not defined anymore in B.rb ?!

Does anyone already face this problem ? Thank you for your help !

[TIG]

Initially define the...
@@var=nil
in the module itself, NOT inside the classes or defs... and then in each class [outside of any defs] you add...
include moduleName
The @@var is then available to all methods in the module and within that module's class ?
You cannot pass @@var between them otherwise...

[driven]

without tests...

shouldn't you require 'B' before trying to use it? i.e. at the top, or before your show method...

john

[inteloide]

Thank you TIG, it works !
Driven, I didn't try your solution, but I want the B file to be part of the module, not outside.

The full code with TIG's solution :
Here is the first file (called 'A.rb'):

require 'sketchup.rb'
module M
	@@var=nil
	class A
		include M
		def initialize
			@@var="123"
		end
		def show
			UI.messagebox( @@var)
			change
			UI.messagebox( @@var)
		end
		require 'B.rb'
	end
	
	Mod=A.new
end #module

if !file_loaded?(__FILE__) then
	m = UI.menu("Plugins").add_item("Test")  {M;;Mod.show  }
end

file_loaded(__FILE__)

And here is the second file ('B.rb'):

include M
def change
	@@var="321"
end

[TIG]

module M
   @@var=nil
   class M;;A
     include M
     ###########

and

module M
   @@var=nil
   class M;;B
     include M
     ###########

???

[Dan Rathbun]

@inteloide said:

And here is the second file ('B.rb'):[/b]

include M
> def change
> 	@@var="321"
> end
> 

Do not do this (above.)

You are including module M into Object, which means you are including module M in EVERYTHING!

file "a.rb"

module M

  module I

    @@var = nil

    def change(val="321")
      @@var = val
    end

  end # module I

end # module M

file "b.rb"

module M

  require("a.rb")

  class A
    include M;;I
  end # class

end # module M

[inteloide]

Hi !

Thank you Dan for your comment, you're right M was include everywhere.
I have seen in your code that you include A.rb in B.rb, I wanted the opposite, so I tried, the code below
For 'A.rb' :

require 'sketchup.rb'
module M
	class A
		require 'B.rb'
		include M;;I
		def initialize
			@@var="123"
		end
		def show
			UI.messagebox( @@var)
			change
			UI.messagebox( @@var)
		end
	end
	
	Mod=A.new
end #module M

if !file_loaded?(__FILE__) then
	m = UI.menu("Plugins").add_item("Test")  {M;;Mod.show  }
end

file_loaded(__FILE__)

For 'B.rb' :

module M
	module I
		@@var=nil
		def change
			@@var="321"
		end
	end #module I
end #Module M

Now, the problem is that @@var must be define in B.rb : what about if I need to create a third file which require @@var ? I must declare again the same variable !
Any solution ? (Because in my plugins, there are a lot of variables used in a lot of sub-programs...
Any help would be apreciated !

[Dan Rathbun]

@inteloide said:

Now, the problem is that @@var must be define in B.rb : what about if I need to create a third file which require @@var ? I must declare again the same variable !

NO.. the @@var is a module variable. It is SHARED by ALL classes and modules that include the mixin module M::I

If you change @@var value from an instance of class M::A, all other instances will see the change. Also any modules that included the M::I mixin will share the @@var. (It is a proxy lookup INTO the mixin library module M::I.)

Files are NOT included (that is a Python feature.) IN Ruby modules are included. A file can define multiple modules.

@inteloide said:

Any solution ? (Because in my plugins, there are a lot of variables used in a lot of sub-programs...

If you want each class instance or sub-module to use it's OWN variables, the use instance vars, ... @var (only a single @ before the variable name.)

This is all basic Ruby, explained in the "Pick-Axe" Book.