How to make modular helper in Sinatra

Question

i want to make a method inside a module (for grouping reason) that can be called as a module.method, something like this:

helpers do
  module UserSession
    def logged_in?
      not session[:email].nil?
    end
    def logout!
      session[:email] = nil
    end
  end
end

but when i try to call it using UserSession.logged_in? it said that logged_in is not UserSession's method

undefined method `logged_in?' for UserSession:Module

when i move the method as UserSession's method:

helpers do
  module UserSession
    def self.logged_in?
      not session[:email].nil? # error
    end
    def self.logout!
      session[:email] = nil
    end
  end
end

it gives an error, that i could not access the session variable

undefined local variable or method `session' for UserSession:Module

what is the best solution for this problem?

Answer 1

You can use a different convention for the helpers method.

module UserSession
  def logged_in?
   not session[:email].nil?
  end
  def logout!
    session[:email] = nil
  end
end

helpers UserSession

get '/foo' do
  if logged_in?
    'Hello you!'
  else
    'Do I know you?'
  end
end

The module definition can of course be in another (required) file.

Behind the scenes, helpers <Module> is doing an include, but not simply into the Sinatra application sub-class you are using for your app. The include needs to be made compatible with how get, post etc work their magic, and helpers does that for you.

Answer 2

nevermind, i found the answer, i have tried define_method('UserSession.logged_in?') also, but no luck

last thing i've tried is:

# outside helpers
class UserSession
  @@session = nil
  def initialize session
    @@session ||= session
  end
  def self.check
    throw('must be initialized first') if @@session.nil?
  end
  def self.logged_in?
    self.check
    not @@session[:email].nil?
  end
  def self.logout
    self.check
    @@session.delete :email
  end
end

but something must be called first

before // do
  UserSession.new session
end

then it can be used as desired:

get '/' do
  if UserSession.logged_in?
    # do something here
  end
end