ActsAsParanoid

Build Status

A Rails plugin to add soft delete.

This gem can be used to hide records instead of deleting them, making them recoverable later.

Support

This branch targets Rails 5.2+ and Ruby 2.4+ only

If you're working with Rails 5.1 and earlier, or with Ruby 2.3 or earlier, please switch to the corresponding branch or require an older version of the acts_as_paranoid gem.

Known issues

  • Using acts_as_paranoid and ActiveStorage on the same model leads to a SystemStackError.
  • You cannot directly create a model in a deleted state, or update a model after it's been deleted.

Usage

Install gem:

gem 'acts_as_paranoid', '~> 0.7.0'
bundle install

Create migration

bin/rails generate migration AddDeletedAtToParanoiac deleted_at:datetime:index

Enable ActsAsParanoid

class Paranoiac < ActiveRecord::Base
  acts_as_paranoid
end

By default, ActsAsParanoid assumes a record's deletion is stored in a datetime column called deleted_at.

Options

If you are using a different column name and type to store a record's deletion, you can specify them as follows:

  • column: 'deleted'
  • column_type: 'boolean'

While column can be anything (as long as it exists in your database), type is restricted to:

  • boolean
  • time or
  • string

Note that the time type corresponds to the database column type datetime in your Rails migrations and schema.

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"). Any records with a non-matching value in this column will be treated normally, i.e., as not deleted.

If your column type is a boolean, it is possible to specify allow_nulls option which is true by default. When set to false, entities that have false value in this column will be considered not deleted, and those which have true will be considered deleted. When true everything that has a not-null value will be considered deleted.

Filtering

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.

When you want to access them, you have 2 choices:

Paranoiac.only_deleted # retrieves only the deleted records
Paranoiac.with_deleted # retrieves all records, deleted or not

When using the default column_type of 'time', the following extra scopes are provided:

time = Time.now

Paranoiac.deleted_after_time(time)
Paranoiac.deleted_before_time(time)

# Or roll it all up and get a nice window:
Paranoiac.deleted_inside_time_window(time, 2.minutes)

Real deletion

In order to really delete a record, just use:

paranoiac.destroy_fully!
Paranoiac.delete_all!(conditions)

NOTE: The .destroy! method is still usable, but equivalent to .destroy. It just hides the object.

Alternatively you can permanently delete a record by calling destroy or delete_all on the object 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:

p = Paranoiac.first

# does NOT delete the first record, just hides it
p.destroy

# deletes the first record from the database
Paranoiac.only_deleted.where(id: p.id).first.destroy

This behaviour can be disabled by setting the configuration option. In a future version, false will be the default setting.

  • double_tap_destroys_fully: false

Recovery

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 recursive option:

Paranoiac.only_deleted.where("name = ?", "not dead yet").first.recover(recursive: false)

If you would like to change this default behavior for one model, you can use the recover_dependent_associations option

class Paranoiac < ActiveRecord::Base
  acts_as_paranoid recover_dependent_associations: false
end

By default, dependent records will be recovered if they were deleted within 2 minutes 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.

The behavior is only available when both parent and dependant are using timestamp fields to mark deletion, which is the default behavior.

This window can be changed with the dependent_recovery_window option:

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 10 minutes of the Paranoic object
  acts_as_paranoid dependent_recovery_window: 10.minutes
end

or in the recover statement

Paranoiac.only_deleted.where("name = ?", "not dead yet").first
  .recover(recovery_window: 30.seconds)

recover!

You can invoke recover! if you wish to raise an error if the recovery fails. The error generally stems from ActiveRecord.

Paranoiac.only_deleted.where("name = ?", "not dead yet").first.recover!
# => ActiveRecord::RecordInvalid: Validation failed: Name already exists

Optionally, you may also raise the error by passing raise_error: true to the recover method. This behaves the same as recover!.

Paranoiac.only_deleted.where("name = ?", "not dead yet").first.recover(raise_error: true)

Validation

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, use 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

p1 = Paranoiac.create(name: 'foo')
p1.destroy

p2 = Paranoiac.new(name: 'foo')
p2.valid? #=> true
p2.save

p1.recover #=> fails validation!

Status

A paranoid object could be deleted or destroyed fully.

You can check if the object is deleted with the deleted? helper

Paranoiac.create(name: 'foo').destroy
Paranoiac.with_deleted.first.deleted? #=> true

After the first call to .destroy the object is deleted?.

You can check if the object is fully destroyed with destroyed_fully? or deleted_fully?.

Paranoiac.create(name: 'foo').destroy
Paranoiac.with_deleted.first.deleted? #=> true
Paranoiac.with_deleted.first.destroyed_fully? #=> false
p1 = Paranoiac.with_deleted.first
p1.destroy # this fully destroys the object
p1.destroyed_fully? #=> true
p1.deleted_fully? #=> true

Scopes

As you've probably guessed, with_deleted and only_deleted are scopes. You can, however, chain them freely with other scopes you might have.

For example:

Paranoiac.pretty.with_deleted

This is exactly the same as:

Paranoiac.with_deleted.pretty

You can work freely with scopes and it will just work:

class Paranoiac < ActiveRecord::Base
  acts_as_paranoid
  scope :pretty, where(pretty: true)
end

Paranoiac.create(pretty: true)

Paranoiac.pretty.count #=> 1
Paranoiac.only_deleted.count #=> 0
Paranoiac.pretty.only_deleted.count #=> 0

Paranoiac.first.destroy

Paranoiac.pretty.count #=> 0
Paranoiac.only_deleted.count #=> 1
Paranoiac.pretty.only_deleted.count #=> 1

Associations

Associations are also supported.

From the simplest behaviors you'd expect to more nifty things like the ones mentioned previously or the usage of the :with_deleted option with belongs_to

class Parent < ActiveRecord::Base
  has_many :children, class_name: "ParanoiacChild"
end

class ParanoiacChild < ActiveRecord::Base
  acts_as_paranoid
  belongs_to :parent

  # You may need to provide a foreign_key like this
  belongs_to :parent_including_deleted, class_name: "Parent",
    foreign_key: 'parent_id', with_deleted: true
end

parent = Parent.first
child = parent.children.create
parent.destroy

child.parent #=> nil
child.parent_including_deleted #=> Parent (it works!)

Callbacks

There are couple of callbacks that you may use when dealing with deletion and recovery of objects. There is before_recover and after_recover which will be triggered before and after the recovery of an object respectively.

Default ActiveRecord callbacks such as before_destroy and after_destroy will be triggered around .destroy! and .destroy_fully!.

class Paranoiac < ActiveRecord::Base
  acts_as_paranoid

  before_recover :set_counts
  after_recover :update_logs
end

Caveats

Watch out for these caveats:

  • You cannot use scopes named with_deleted and only_deleted
  • You cannot use scopes named deleted_inside_time_window, deleted_before_time, deleted_after_time if your paranoid column's type is time
  • You cannot name association *_with_deleted
  • unscoped will return all records, deleted or not

Acknowledgements

See LICENSE.