PermanentRecords

http://github.com/JackDanger/permanent_records/

This gem prevents any of your ActiveRecord data from being destroyed. Any model that you've given a "deleted_at" datetime column will have that column set rather than let the record be deleted.

Compatability: This gem works with Rails versions 1, 2, and 3

Does it make a lot of sense?

Yes.

User.find(3).destroy          # sets the 'deleted_at' attribute to Time.now and returns a frozen record
User.find(3).destroy(:force)  # executes the real destroy method, the record will be removed from the database
User.destroy_all              # soft-deletes all User records
User.delete_all               # bye bye everything (no soft-deleting here)

There are also two scopes provided for easily searching deleted and not deleted records:

User.deleted.find(...)        # only returns deleted records.
User.not_deleted.find(...)    # only returns non-deleted records.

Note: Your normal finds will, by default, include deleted records. You'll have to manually use the 'not_deleted' scope to avoid this:

User.find(1)                  # will find record number 1, even if it's deleted
User.not_deleted.find(1)      # This is probably what you want, it doesn't find deleted records

Is Everything Automated?

Yes. You don't have to change ANY of your code to get permanent archiving of all your data with this gem. When you call 'destroy' on any record (or 'destroy_all' on a class or association) your records will all have a deleted_at timestamp set on them.

Can I easily undelete records?

Yes. All you need to do is call the 'revive' method.

User.find(3).destroy
# the user is now deleted
User.find(3).revive
# the user is back to it's original state

And if you had dependent records that were set to be destroyed along with the parent record:

class User < ActiveRecord::Base
  has_many :comments, :dependent => :destroy
end
User.find(3).destory
# all the comments are destroyed as well
User.find(3).revive
# all the comments that were just destroyed are now back in pristine condition

# forcing deletion works the same way: fi you hard delete a record, its dependent records will also be hard deleted

Can I use default scopes?

In Rails 3, yes.

default_scope where(:deleted_at => nil)

If you use such a default scope, you will need to simulate the deleted scope with a method

def self.deleted
  self.unscoped.where('deleted_at IS NOT NULL')
end

Rails 2 provides no practical means of overriding default scopes (aside from using something like Model.with_exclusive_scope { find(id) }), so you'll need to implement those yourself if you need them.

Patches welcome, forks celebrated.