Question

How do I write a ruby method that may be called by appending the method name to an object?

i.e. get the quarter period of a specified date

def quarter(dateObject)
  quarters = { 1 => 1, 2 => 1, 3 => 1, 4 => 2, 5 => 2, 6 => 2, 7 => 3, 8 => 3, 9 => 3, 10 => 4, 11 => 4, 12 => 4 }
  quarters[dateObject.month]
end

I can use this method now like this:

quarter(Date.today)

but how do I manage to use it like this:

Date.today.quarter

or, even better, in both ways?

Answer 1

You can patch it into the class. Be wary of what you are doing and make sure the method doesn’t already exist when modifying a class.

class Date
  def quarter
    quarters = { 1 => 1, 2 => 1, 3 => 1, 4 => 2, 5 => 2, 6 => 2, 7 => 3, 8 => 3, 9 => 3, 10 => 4, 11 => 4, 12 => 4 }
    quarters[self.month] #self is your instance of the Date object
  end
end