Undefined Method - Calling a class in one file from another - ruby

Question

I am trying to learn a little about GUI testing with Ruby & Cucumber, partially following a book called "Scripted GUI Testing with Ruby" by Ian Dees. I'm new to Ruby, and I'm facing what seems like a simple problem - undefined method. I have two classes, each in different modules. The first class will handle Win32API calls, the second represents the top level of the application (boot-up, close, find window etc). They will work a little like page objects, separating UI interaction logic from test logic. I'm getting an undefined method on the Windows API class, for user32:
#Win32API class
require 'Win32API'
class WindowsAPI
def user32(name, param_types, return_value)
Win32API.new 'user32', name, param_types, return_value
end
#find_window = user32 'FindWindow', ['P', 'P'], 'L'
end
The second:
#Application class
require_relative 'WindowsAPI'
class VideoLibrarian
#main_win_title = "VidLibMainWin"
attr_accessor :main_win_handle, :win_api
def initialize
#win_api = WindowsAPI.new
end
def Start()
system 'start "" "C:/Users/VideoAnalyser.exe"'
sleep 0.2 while (#main_win_handle = win_api.find_window.call nil, #main_win_title) <= 0
end
end
vl = VideoLibrarian.new
vl.Start
The full stack trace/ error message is:
C:/Users/Ruby Scripts/vidlibtests/WindowsAPI.rb:11:in `<class:WindowsAPI>': undefined method `user32' for WindowsAPI:Class (NoMethodError)
from C:/Users/Ruby Scripts/vidlibtests/WindowsAPI.rb:5:in `<top (required)>'
from C:/Users/Ruby Scripts/vidlibtests/VideoLibrarian.rb:3:in `require_relative'
from C:/Users/Ruby Scripts/vidlibtests/VideoLibrarian.rb:3:in `<main>'
Any help greatly appreciated!

Answer 1

You defined user32 as an instance method while you clearly need it to be class method of WindowsAPI class:
def self.user32(name, param_types, return_value)
Win32API.new 'user32', name, param_types, return_value
end