Persons Demo

gistfile1.rb

@person = Person.first  # a Person
link_to @person.name, @person  # => /persons/1
@student = Student.first # a Student
link_to @student.name, @student # => /students/2

# this allows stuff like this:
@persons = Person.all   # Person.all also includes Students
# @persons will look like this: [Person, Student, ..]
@persons.each do |p|
  link_to p.name, p
end
# => /persons/1, /students/2

migration.rb

class AddTypeColumnToPersons < ActiveRecord::Migration
  def change
    add_column :person, :type, :string
  end
end

models.rb

class Person < ActiveRecord::Base
end
class Student < Person
end

polymorphic.rb

@persons = Person.all
@persons.each do |p|
  link_to @p.name, edit_polymorphic_path(p)
end
# => /persons/1/edit, /students/2/edit

tricky.rb

@persons = Person.all
@persons.each do |p|
  link_to p.name, edit_person_path(p)
  # => /persons/1/edit, /persons/2/edit
end