A simple plugin which hides records instead of deleting them, being able to recover them.
While porting it to Rails 3, I decided to apply the ideas behind those plugins to an unified solution while removing a lot of the complexity found in them. I eventually ended up writing a new plugin from scratch.
You can enable ActsAsParanoid like this:
class Paranoiac < ActiveRecord::Base acts_as_paranoid end
You can also specify the name of the column to store it's deletion and the type of data it holds:
- :column => 'deleted_at'
- :type => 'time'
The values shown are the defaults. While column can be anything (as long as it exists in your database), type is restricted to "boolean", "time" or "string".
If your column type is a "string", you can also specify which value to use when marking an object as deleted by passing
:deleted_value (default is "deleted").
If a record is deleted by ActsAsParanoid, it won't be retrieved when accessing the database. So,
Paranoiac.all will not include the deleted_records. if you want to access them, you have 2 choices:
Paranoiac.only_deleted # retrieves the deleted records Paranoiac.with_deleted # retrieves all records, deleted or not
In order to really delete a record, just use:
You can also definitively delete a record by calling
delete_all on it twice. If a record was already deleted (hidden by ActsAsParanoid) and you delete it again, it will be removed from the database. Take this example:
Paranoiac.first.destroy # does NOT delete the first record, just hides it Paranoiac.only_deleted.destroy # deletes the first record from the database
Recovery is easy. Just invoke
recover on it, like this:
Paranoiac.only_deleted.where("name = ?", "not dead yet").first.recover
All associations marked as
:dependent => :destroy are also recursively recovered. If you would like to disable this behavior, you can call
recover with the
Paranoiac.only_deleted.where("name = ?", "not dead yet").first.recover(:recursive => false)
If you would like to change the default behavior for a model, you can use the
class Paranoiac < ActiveRecord::Base acts_as_paranoid :recover_dependent_associations => false end
By default when using timestamp fields to mark deletion, dependent records will be recovered if they were deleted within 5 seconds of the object upon which they depend. This restores the objects to the state before the recursive deletion without restoring other objects that were deleted earlier. This window can be changed with the
class Paranoiac < ActiveRecord::Base acts_as_paranoid has_many :paranoids, :dependent => :destroy end class Paranoid < ActiveRecord::Base belongs_to :paranoic # Paranoid objects will be recovered alongside Paranoic objects # if they were deleted within 1 minute of the Paranoic object acts_as_paranoid :dependent_recovery_window => 1.minute end
or in the recover statement
Paranoiac.only_deleted.where("name = ?", "not dead yet").first.recover(:recovery_window => 30.seconds)
ActiveRecord's built-in uniqueness validation does not account for records deleted by ActsAsParanoid. If you want to check for uniqueness among non-deleted records only, use the macro
validates_as_paranoid in your model. Then, instead of using
validates_uniqueness_of_without_deleted. This will keep deleted records from counting against the uniqueness check.
class Paranoiac < ActiveRecord::Base acts_as_paranoid validates_as_paranoid validates_uniqueness_of_without_deleted :name end Paranoiac.create(:name => 'foo').destroy Paranoiac.new(:name => 'foo').valid? #=> true
Once you retrieve data using
with_deleted scope you can check deletion status using
Paranoiac.create(:name => 'foo').destroy Paranoiac.with_deleted.first.deleted? #=> true
Watch out for these caveats:
- You cannot use default_scope in your model. It is possible to work around this caveat, but it's not pretty. Have a look at this article if you really need to have your own default scope.
- You cannot use scopes named
unscopedwill return all records, deleted or not
- To cheerfulstoic for adding recursive recovery
- To Jonathan Vaught for adding paranoid validations
- To Geoffrey Hichborn for improving the overral code quality and adding support for after_commit
- To flah00 for adding support for STI-based associations (with :dependent)
- To vikramdhillon for the idea and initial implementation of support for string column type
Copyright © 2010 Gonçalo Silva, released under the MIT license