DestroyedAt

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Installation

Add the destroyed_at gem to your Gemfile

gem 'destroyed_at'

You can either mixin the modules on a case-by-case basis:

class User < ActiveRecord::Base
  include DestroyedAt
end

or make the changes globally:

class ActiveRecord::Base
  include DestroyedAt
end

Please note you will need to make a migration

Each model's table that is expected to have this behavior must have a destroyed_at column of type DateTime.

It is recommended that you add an index on the model's destroyed_at column, so that your database does not have to do a table scan for every query. Only Postgres' query indexes will be of any benefit:

CREATE INDEX ON users WHERE destroyed_at IS NULL;
CREATE INDEX ON users WHERE destroyed_at IS NOT NULL;

Usage

Allows you to "destroy" an object without deleting the record or associated records.

Destroying

Overides #destroy to set #destroyed_at to the current time on an object. The default scope of the class is then set to return objects that have not been destroyed (i.e., have nil for their destroyed_at value).

#destroyed? will be true when your model is destroyed; it will be false when your model has been restored.

class User < ActiveRecord::Base
  include DestroyedAt
end

user = User.create
user.destroy 
# => true
user.destroyed_at
# => <DateTime>

Warning: Dependent relations with destroy

Be careful when destroying parent relationships that have dependent: :destroy. If the child relationship does not also include DestroyedAt, then when you call #destroy on the parent instance, you will delete the child record, rather than simply marking it destroyed_at.

The same goes for destroying through relations that omit include DestroyedAt, even if the parent and child models include the mixin.

Restoring

When you'd like to "restore" a record, call the #restore method on the instance. This will set its #destroyed_at value to nil, thereby including it in the default scope of the class again.

To include this functionality on has_many through relationships, be sure to include DestroyedAt on the through model, as well as the parent model.

class User < ActiveRecord::Base
  include DestroyedAt
end

user = User.create
user.destroy
user.restore
# => true
user.destroyed_at
# => nil

Destroyed Scope

When you include the DestroyedAt module, it sets a default scope of where(destroyed_at: nil). It also defines a scope called .destroyed which removes the default scope and finds the records of a relation where.not(destroyed_at: nil). This is different than calling unscoped on the class/relation. Where unscoped will remove all scoping from a relation, .destroyed only removes the default scope generated by the DestroyedAt module, making it safe to call on relations.

Callbacks

before_restore, after_restore and around_restore callbacks are added to your model. They work similarly to the before_destroy, after_destroy and around_restore callbacks.

class User < ActiveRecord::Base
  before_restore :before_restore_action
  after_restore  :after_restore_action
  around_restore :around_restore_action

  private

  def before_restore_action
    ...
  end

  def after_restore_action
    ...
  end

  def around_restore_action
    # before around
    yield # restoring...
    # after around
end

Validations

If you are using the uniqueness validator you will need to run it as:

validates :email, uniqueness: { conditions: -> { where(destroyed_at: nil) } }

Rails will by default not include default_scopes when querying for uniqueness. Rather than monkey patching the validator we believe this is the best solution.

Authors

We are very thankful for the many contributors

Versioning

This gem follows Semantic Versioning

Want to help?

Please do! We are always looking to improve this gem. Please see our Contribution Guidelines on how to properly submit issues and pull requests.

Legal

DockYard Inc. © 2014

@dockyard

Licensed under the MIT license