Student Presenter example

student_presenter.rb

# stored in app/presenters/student_presenter.rb
class StudentPresenter < SimpleDelegator

  delegate :email, to: :user

  def initialize(student)
    @student = super(student)
  end
  
  def self.find(id)
    new(Student.find(id))
  end
  
  def display_name
    name.present? ? name : "-"
  end
  
  def display_university
    university.present? ? university.name : "University not found"
  end
end

students_controller.rb

class StudetntsController < ApplicationController
  
  def index
    @students = Student.all.map{|s| StudentPresenter.new(s)}
  end
  
  def show
    @student = StudentPresenter.find(params[:id])
  end
end