ActsAsArchival

Atomically archive object trees in your activerecord models.

We had the problem that acts_as_paranoid and similar plugins/gems always work on a record-by-record basis and made it very difficult to restore records atomically (or archive them, for that matter).

Because the archive and unarchive methods are in transactions, and every archival record involved gets the same archive number upon archiving, you can easily restore or remove an entire set of records without having to worry about partial deletion or restoration.

Additionally, other plugins generally screw with how destroy/delete work. We don't because we actually want to be able to destroy records.

Maintenance

You might read the commit logs and think "This must be abandonware! This hasn't been updated in 2y!" But! This is a mature project that solves a specific problem in ActiveRecord. It tends to only be updated when a new major version of ActiveRecord comes out and hence the infrequent updates.

Install

Gemfile:

gem "acts_as_archival"

Any models you want to be archival should have the columns archive_number (String) and archived_at (DateTime).

i.e. rails g migration AddAAAToPost archive_number archived_at:datetime

Any dependent-destroy AAA model associated to an AAA model will be archived with its parent.

If you're stuck on Rails 4.0x/3x/2x, check out the older tags/branches, which are no longer in active development.

Example

class Hole < ActiveRecord::Base
  acts_as_archival
  has_many :rats, dependent: :destroy
end

class Rat < ActiveRecord::Base
  acts_as_archival
end

Simple interactions & scopes

h = Hole.create                  #
h.archived?                      # => false
h.archive!                       # => true
h.archived?                      # => true
h.archive_number                 # => "b56876de48a5dcfe71b2c13eec15e4a2"
h.archived_at                    # => Thu, 01 Jan 2012 01:49:21 -0400
h.unarchive!                     # => true
h.archived?                      # => false
h.archive_number                 # => nil
h.archived_at                    # => nil

Associations

h = Hole.create                  #
r = h.rats.create                #
h.archive!                       # => true
h.archive_number                 # => "b56876de48a5dcfe71b2c13eec15e4a2"
r.archived_at                    # => Thu, 01 Jan 2012 01:52:12 -0400
r.archived?                      # => true
h.unarchive!                     # => true
h.archive_number                 # => nil
r.archived_at                    # => nil
r.archived?                      # => false

Relations

Hole.create!
Hole.create!
Hole.create!

holes = Hole.all

# All records in the relation will be archived with the same archive_number.
# Dependent/Destroy relationships will be archived, and callbacks will still be honored.
holes.archive_all!              # => [array of Hole records in the relation]

holes.first.archive_number      # => "b56876de48a5dcfe71b2c13eec15e4a2"
holes.last.archive_number       # => "b56876de48a5dcfe71b2c13eec15e4a2"

holes.unarchive_all!            # => [array of Hole records in the relation]

Scopes

h = Hole.create
Hole.archived.size               # => 0
Hole.unarchived.size             # => 1
h.archive!
Hole.archived.size               # => 1
Hole.unarchived.size             # => 0

Utility methods

h = Hole.create                  #
h.archival?                   # => true
Hole.archival?                # => true

Options

When defining an AAA model, it is is possible to make it unmodifiable when it is archived by passing readonly_when_archived: true to the acts_as_archival call in your model.

class CantTouchThis < ActiveRecord::Base
  acts_as_archival readonly_when_archived: true
end

record = CantTouchThis.create(foo: "bar")
record.archive!                              # => true
record.foo = "I want this to work"
record.save                                  # => false
record.errors.full_messages.first            # => "Cannot modify an archived record."

Callbacks

AAA models have four additional callbacks to do any necessary cleanup or other processing before and after archiving and unarchiving, and can additionally halt the archive callback chain.

class Hole < ActiveRecord::Base
  acts_as_archival

  # runs before #archive!
  before_archive :some_method_before_archiving

  # runs after #archive!
  after_archive :some_method_after_archiving

  # runs before #unarchive!
  before_unarchive :some_method_before_unarchiving

  # runs after #unarchive!
  after_unarchive :some_method_after_unarchiving

  # ... implement those methods
end

Halting the callback chain

• Rails 4.2 - the callback method should return a false/nil value.
• Rails 5.x - the callback should throw(:abort)/raise(:abort).

Caveats

1. This will only work on associations that are dependent destroy. It should be trival to change that or make it optional.
2. If you would like to work on this, you will need to setup sqlite on your development machine. Alternately, you can disable specific dev dependencies in the gemspec and test_helper and ask for help.

Testing

Running the tests should be as easy as:

script/setup                 # bundles, makes databases with permissions
rake                         # run tests on latest Rails
appraisal rake               # run tests on all versions of Rails

Check out more on appraisal if you need to add new versions of things or run into a version bug.

Help Wanted

We'd love to have your help making this better! If you have ideas for features this should implement or you think the code sucks, let us know. And PRs are greatly appreciated. 👍

Thanks

ActsAsParanoid and PermanentRecords were both inspirations for this:

• http://github.com/technoweenie/acts_as_paranoid
• http://github.com/fastestforward/permanent_records

Contributors

• Joel Meador
• Michael Kuehl
• Matthew Gordon
• Vojtech Salbaba
• David Jones
• Dave Woodward
• Miles Sterrett
• James Hill
• Maarten Claes
• Anthony Panozzo
• Aaron Milam
• Anton Rieder
• Josh Menden
• Sergey Gnuskov

Thanks!

Copyright (c) 2009-2017 Expected Behavior, LLC, released under the MIT license