undefined function error from a module inside class in rails

user_6703569 0
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I have a module Helper which is present in app/models/concerns/helper.rb

module Helper
  def func
    return ['A', 'B', 'C']
  end
end

I have a class NewService which is present in app/services/pqr/new_service.rb

module PQR
  class NewService < ApplicationService
    include Helper
    @@results = func

    def self.another_func
      if @@results.blank?
        @@results = func
      end
    end
  end
end

On calling the function: PQR::NewService.another_func
I am getting the error: (undefined local variable or method func for PQR::NewService:Class)

Ruby version - 2.5.3
Rails version - 5.2.3
ruby-on-rails ruby
2 Answers

You are calling func from inside class scope; why would you expect instance-scoped methods to be accessible from there? This is an MCVE for your code

class Foo
  def func; end # instance method
  func          # class scope
end

To make func accessible, one should make it available on class level. That means, you should include your concern into singleton_class of PQR.

Contrived example:

module Foo
  def func; puts "YO"; end
end

class Bar
  class << self
    include Foo
  end

  func
end
user_20352620

You're including the Helper, not extending it.

e.g you're calling func in the class definition but you added it as an instance method

Basically, do

extend Helper
user_122446080
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