When to use self[:foo] in models

rubyonrails-talk
1

I’ve always been a little unclear on accessing attributes of an ActiveRecord model within the class itself, i.e.

def full_name “#{first_name} #{last_name}” end

or

def full_name “#{self[:first_name]} #{self[:last_name]}” end

This is a contrieved example and I think both work, but I’ve found other times where doing something similar doesn’t work without the self[:]. Can someone shed some light on what the difference is?

Thanks!

2

This is a contrieved example and I think both work, but I've found other times where doing something similar doesn't work without the self[:]. Can someone shed some light on what the difference is?

I think it's preferable to use the methods rather than the hash interface. The only situation I've come across where you cannot use the method is single-table inheritance, where you have to use self[:type] instead of type because type is a built-in (though deprecated) method.

- Mark.