Question

I am busy making a ruby on rails app.

I want to make an model that contains a text model, a picture model and a link model. Every model can have comments, But i don’t want to make different comment models for the text, picture and link model. Is it possible to make a media model witch has a subclass(or how it is called) aka: picture model, text model and link model. Or is there an other clean way to do this.
Thanks

Answer 1

You can create Comment model that has polymorphic association:

# Comment model
belongs_to :commentable, :polymorphic => true

# Other model that should has comments
has_many :comments, :as => :commentable

You can add above line to every model that needs comments. In order to have polymorphic association you need to have those columns in comments table in db:

commentable_id   - int
commentable_type - string

You can also use some plugin for comments, on example this.