How to change class of an STI object?

rubyonrails-talk
1

I have some models which use the same table via single table inheritance. I (think I) need to change objects from one class to another and not sure how to go about that.

Consider these models:

  class Project < ActiveRecord::Base   end

  class Goal < Project # inherits project characteristics   end

  class Assignment < Project # inherits project characteristics   end

They are distinguished from each other by the 'type' column.

  class CreateProjects < ActiveRecord::Migration     def self.up       create_table :projects do |t|         t.column :type, :string         ...       end     end   end

How would I convert a 'Project' object into a 'Goal' object while preserving other characteristics (id, title, etc.)?

Thanks!

2

Just change the value in the type column to change the type to any of the other types. I define a method that aliases to type to make it easier to access. You will need to reload the data to get a different Ruby object.

Michael

3

Thanks Michael. That's simple enough!