访问Ruby模块中的方法

Question

I'm writing my first Ruby module and I have this:

/app/module/test_modules/test.rb

test.rb looks similar to:

module TestModules
  module Test

    def test
      puts 'this is a test'
    end
  end
end

When I call the following from console, I get:

(main)> TestModule::Test.test
//NoMethodError: private method `test' called for TestModules::Test:Module

How do I make test() visible?

Answer 1

You are calling a class method, whereas you defined test as an instance method. You could call it the way you want if you used the module via include or extend . This article does a good job explaining.

module TestModules
  module Test
    def self.test
      puts 'this is a test'
    end
  end
end

Answer 2

Also,

1)

module TestModules
  module Test
    def test
      puts 'this is a test'
    end

    module_function :test
  end
end

2)

module TestModules
  module Test
    extend self
    def test
      puts 'this is a test'
    end
  end
end

Answer 3

The way that you have defined your method, it is a method on an instance of Test - thus it would work if you did:

blah = TestModule::Test.new
blah.test

note - and do use it this way, you would need to define Test as a class not a module

If you want the function to work on the class itself, then you need to define it like so:

def self.test
    ....
end

And then you can do TestModules::Test.test

Answer 4

the test method you defined is instance method...try this

module TestModules
  module Test
    def self.test
      puts 'this is a test'
    end
  end
end

now you can call the method by this TestModules::Test.test