Track changes to your models, for auditing or versioning. See how a model looked at any stage in its lifecycle, revert it to any version, or restore it after it has been destroyed.
- Features
- Compatibility
- Installation
- API Summary
- Basic Usage
- Limiting What is Versioned, and When
- Working With Versions
- Finding Out Who Was Responsible For A Change
- Custom Version Classes
- Associations
- Storing metadata
- Using a custom serializer
- SerializedAttributes support
- Testing
- Stores create, update and destroy events
- Does not store updates which don't change anything
- Support for versioning associated records
- Can store metadata with each version record
- Who was responsible for a change
- Arbitrary model-level metadata (useful for filtering versions)
- Arbitrary controller-level information e.g. remote IP
- Configurable
- No configuration necessary, but if you want to ..
- Configure which events (create, update and destroy) are versioned
- Configure which attributes must change for an update to be versioned
- Turn off/on by model, request, or globally
- Use separate tables for separate models
- Extensible
- Write a custom version class for complete control
- Write custom version classes for each of your models
- Work with versions
- Restore any version, including the original, even once destroyed
- Restore any version even if the schema has since changed
- Restore the version as of a particular time
- Thoroughly tested
- Threadsafe
paper_trail | branch | tags | ruby | activerecord |
---|---|---|---|---|
4 | master | v4.x | >= 1.8.7 | >= 3.0, < 6 |
3 | 3.0-stable | v3.x | >= 1.8.7 | >= 3.0, < 5 |
2 | 2.7-stable | v2.x | >= 1.8.7 | >= 3.0, < 4 |
1 | rails2 | v1.x | >= 1.8.7 | >= 2.3, < 3 |
-
Add PaperTrail to your
Gemfile
.gem 'paper_trail', '~> 4.0.0'
-
Generate a migration which will add a
versions
table to your database.bundle exec rails generate paper_trail:install
-
Run the migration.
bundle exec rake db:migrate
-
Add
has_paper_trail
to the models you want to track.
In order to configure PaperTrail for usage with Sinatra, your Sinatra
app must be using ActiveRecord
3 or 4. It is also recommended to use the
Sinatra ActiveRecord Extension or something similar for managing your
applications ActiveRecord
connection in a manner similar to the way Rails
does. If using the aforementioned Sinatra ActiveRecord Extension
, steps for
setting up your app with PaperTrail will look something like this:
-
Add PaperTrail to your
Gemfile
.gem 'paper_trail', '~> 4.0.0'
-
Generate a migration to add a
versions
table to your database.bundle exec rake db:create_migration NAME=create_versions
-
Copy contents of create_versions.rb into the
create_versions
migration that was generated into yourdb/migrate
directory. -
Run the migration.
bundle exec rake db:migrate
-
Add
has_paper_trail
to the models you want to track.
PaperTrail provides a helper extension that acts similar to the controller mixin
it provides for Rails
applications.
It will set PaperTrail.whodunnit
to whatever is returned by a method named
user_for_paper_trail
which you can define inside your Sinatra Application. (by
default it attempts to invoke a method named current_user
)
If you're using the modular Sinatra::Base
style of application, you will
need to register the extension:
# bleh_app.rb
require 'sinatra/base'
class BlehApp < Sinatra::Base
register PaperTrail::Sinatra
end
When you declare has_paper_trail
in your model, you get these methods:
class Widget < ActiveRecord::Base
has_paper_trail # you can pass various options here
end
# Returns this widget's versions. You can customise the name of the association.
widget.versions
# Return the version this widget was reified from, or nil if it is live.
# You can customise the name of the method.
widget.version
# Returns true if this widget is the current, live one; or false if it is from a previous version.
widget.live?
# Returns who put the widget into its current state.
widget.paper_trail_originator
# Returns the widget (not a version) as it looked at the given timestamp.
widget.version_at(timestamp)
# Returns the widget (not a version) as it was most recently.
widget.previous_version
# Returns the widget (not a version) as it became next.
widget.next_version
# Generates a version for a `touch` event (`widget.touch` does NOT generate a version)
widget.touch_with_version
# Turn PaperTrail off for all widgets.
Widget.paper_trail_off!
# Turn PaperTrail on for all widgets.
Widget.paper_trail_on!
# Check whether PaperTrail is enabled for all widgets.
Widget.paper_trail_enabled_for_model?
widget.paper_trail_enabled_for_model? # only available on instances of versioned models
And a PaperTrail::Version
instance has these methods:
# Returns the item restored from this version.
version.reify(options = {})
# Return a new item from this version
version.reify(dup: true)
# Returns who put the item into the state stored in this version.
version.paper_trail_originator
# Returns who changed the item from the state it had in this version.
version.terminator
version.whodunnit
version.version_author
# Returns the next version.
version.next
# Returns the previous version.
version.previous
# Returns the index of this version in all the versions.
version.index
# Returns the event that caused this version (create|update|destroy).
version.event
# Query versions objects by attributes.
PaperTrail::Version.where_object(attr1: val1, attr2: val2)
# Query versions object_changes field by attributes (requires
# `object_changes` column on versions table).
# Also can't guarantee consistent query results for numeric values
# due to limitations of SQL wildcard matchers against the serialized objects.
PaperTrail::Version.where_object_changes(attr1: val1)
In your controllers you can override these methods:
# Returns the user who is responsible for any changes that occur.
# Defaults to current_user.
user_for_paper_trail
# Returns any information about the controller or request that you want
# PaperTrail to store alongside any changes that occur.
info_for_paper_trail
PaperTrail is simple to use. Just add 15 characters to a model to get a paper
trail of every create
, update
, and destroy
.
class Widget < ActiveRecord::Base
has_paper_trail
end
This gives you a versions
method which returns the paper trail of changes to
your model.
widget = Widget.find 42
widget.versions
# [<PaperTrail::Version>, <PaperTrail::Version>, ...]
Once you have a version, you can find out what happened:
v = widget.versions.last
v.event # 'update' (or 'create' or 'destroy')
v.whodunnit # '153' (if the update was via a controller and
# the controller has a current_user method,
# here returning the id of the current user)
v.created_at # when the update occurred
widget = v.reify # the widget as it was before the update;
# would be nil for a create event
PaperTrail stores the pre-change version of the model, unlike some other auditing/versioning plugins, so you can retrieve the original version. This is useful when you start keeping a paper trail for models that already have records in the database.
widget = Widget.find 153
widget.name # 'Doobly'
# Add has_paper_trail to Widget model.
widget.versions # []
widget.update_attributes :name => 'Wotsit'
widget.versions.last.reify.name # 'Doobly'
widget.versions.last.event # 'update'
This also means that PaperTrail does not waste space storing a version of the
object as it currently stands. The versions
method gives you previous
versions; to get the current one just call a finder on your Widget
model as
usual.
Here's a helpful table showing what PaperTrail stores:
Event | Model Before | Model After |
---|---|---|
create | nil | widget |
update | widget | widget |
destroy | widget | nil |
PaperTrail stores the values in the Model Before column. Most other auditing/versioning plugins store the After column.
You can choose which events to track with the on
option. For example, to
ignore create
events:
class Article < ActiveRecord::Base
has_paper_trail :on => [:update, :destroy]
end
You may also have the PaperTrail::Version
model save a custom string in it's
event
field instead of the typical create
, update
, destroy
. PaperTrail
supplies a custom accessor method called paper_trail_event
, which it will
attempt to use to fill the event
field before falling back on one of the
default events.
a = Article.create
a.versions.size # 1
a.versions.last.event # 'create'
a.paper_trail_event = 'update title'
a.update_attributes :title => 'My Title'
a.versions.size # 2
a.versions.last.event # 'update title'
a.paper_trail_event = nil
a.update_attributes :title => "Alternate"
a.versions.size # 3
a.versions.last.event # 'update'
You can choose the conditions when to add new versions with the if
and
unless
options. For example, to save versions only for US non-draft
translations:
class Translation < ActiveRecord::Base
has_paper_trail :if => Proc.new { |t| t.language_code == 'US' },
:unless => Proc.new { |t| t.type == 'DRAFT' }
end
You can ignore changes to certain attributes like this:
class Article < ActiveRecord::Base
has_paper_trail :ignore => [:title, :rating]
end
This means that changes to just the title
or rating
will not store another
version of the article. It does not mean that the title
and rating
attributes will be ignored if some other change causes a new
PaperTrail::Version
to be created. For example:
a = Article.create
a.versions.length # 1
a.update_attributes :title => 'My Title', :rating => 3
a.versions.length # 1
a.update_attributes :title => 'Greeting', :content => 'Hello'
a.versions.length # 2
a.previous_version.title # 'My Title'
Or, you can specify a list of all attributes you care about:
class Article < ActiveRecord::Base
has_paper_trail :only => [:title]
end
This means that only changes to the title
will save a version of the article:
a = Article.create
a.versions.length # 1
a.update_attributes :title => 'My Title'
a.versions.length # 2
a.update_attributes :content => 'Hello'
a.versions.length # 2
a.previous_version.content # nil
The :ignore
and :only
options can also accept Hash
arguments, where the :
class Article < ActiveRecord::Base
has_paper_trail :only => [:title => Proc.new { |obj| !obj.title.blank? } ]
end
This means that if the title
is not blank, then only changes to the title
will save a version of the article:
a = Article.create
a.versions.length # 1
a.update_attributes :content => 'Hello'
a.versions.length # 2
a.update_attributes :title => 'My Title'
a.versions.length # 3
a.update_attributes :content => 'Hai'
a.versions.length # 3
a.previous_version.content # "Hello"
a.update_attributes :title => 'Dif Title'
a.versions.length # 4
a.previous_version.content # "Hai"
Passing both :ignore
and :only
options will result in the article being
saved if a changed attribute is included in :only
but not in :ignore
.
You can skip fields altogether with the :skip
option. As with :ignore
,
updates to these fields will not create a new PaperTrail::Version
. In
addition, these fields will not be included in the serialized version of the
object whenever a new PaperTrail::Version
is created.
For example:
class Article < ActiveRecord::Base
has_paper_trail :skip => [:file_upload]
end
Sometimes you don't want to store changes. Perhaps you are only interested in changes made by your users and don't need to store changes you make yourself in, say, a migration -- or when testing your application.
You can turn PaperTrail on or off in three ways: globally, per request, or per class.
On a global level you can turn PaperTrail off like this:
PaperTrail.enabled = false
For example, you might want to disable PaperTrail in your Rails application's
test environment to speed up your tests. This will do it (note: this gets done
automatically for RSpec
and Cucumber
, please see the Testing
section):
# in config/environments/test.rb
config.after_initialize do
PaperTrail.enabled = false
end
If you disable PaperTrail in your test environment but want to enable it for specific tests, you can add a helper like this to your test helper:
# in test/test_helper.rb
def with_versioning
was_enabled = PaperTrail.enabled?
was_enabled_for_controller = PaperTrail.enabled_for_controller?
PaperTrail.enabled = true
PaperTrail.enabled_for_controller = true
begin
yield
ensure
PaperTrail.enabled = was_enabled
PaperTrail.enabled_for_controller = was_enabled_for_controller
end
end
And then use it in your tests like this:
test "something that needs versioning" do
with_versioning do
# your test
end
end
You can turn PaperTrail on or off per request by adding a
paper_trail_enabled_for_controller
method to your controller which returns
true
or false
:
class ApplicationController < ActionController::Base
def paper_trail_enabled_for_controller
request.user_agent != 'Disable User-Agent'
end
end
If you are about to change some widgets and you don't want a paper trail of your changes, you can turn PaperTrail off like this:
Widget.paper_trail_off!
And on again like this:
Widget.paper_trail_on!
You can call a method without creating a new version using without_versioning
.
It takes either a method name as a symbol:
@widget.without_versioning :destroy
Or a block:
@widget.without_versioning do
@widget.update_attributes :name => 'Ford'
end
Configure version_limit
to cap the number of versions saved per record. This
does not apply to create
events.
# Limit: 4 versions per record (3 most recent, plus a `create` event)
PaperTrail.config.version_limit = 3
# Remove the limit
PaperTrail.config.version_limit = nil
PaperTrail makes reverting to a previous version easy:
widget = Widget.find 42
widget.update_attributes :name => 'Blah blah'
# Time passes....
widget = widget.previous_version # the widget as it was before the update
widget.save # reverted
Alternatively you can find the version at a given time:
widget = widget.version_at(1.day.ago) # the widget as it was one day ago
widget.save # reverted
Note version_at
gives you the object, not a version, so you don't need to call
reify
.
Undeleting is just as simple:
widget = Widget.find 42
widget.destroy
# Time passes....
widget = PaperTrail::Version.find(153).reify # the widget as it was before destruction
widget.save # the widget lives!
You could even use PaperTrail to implement an undo system, Ryan Bates has!
If your model uses optimistic locking don't forget to increment your
lock_version
before saving or you'll get a StaleObjectError
.
You can call previous_version
and next_version
on an item to get it as it
was/became. Note that these methods reify the item for you.
live_widget = Widget.find 42
live_widget.versions.length # 4 for example
widget = live_widget.previous_version # => widget == live_widget.versions.last.reify
widget = widget.previous_version # => widget == live_widget.versions[-2].reify
widget = widget.next_version # => widget == live_widget.versions.last.reify
widget.next_version # live_widget
If instead you have a particular version
of an item you can navigate to the
previous and next versions.
widget = Widget.find 42
version = widget.versions[-2] # assuming widget has several versions
previous = version.previous
next = version.next
You can find out which of an item's versions yours is:
current_version_number = version.index # 0-based
If you got an item by reifying one of its versions, you can navigate back to the version it came from:
latest_version = Widget.find(42).versions.last
widget = latest_version.reify
widget.version == latest_version # true
You can find out whether a model instance is the current, live one -- or whether
it came instead from a previous version -- with live?
:
widget = Widget.find 42
widget.live? # true
widget = widget.previous_version
widget.live? # false
And you can perform WHERE
queries for object versions based on attributes:
# All versions that meet these criteria.
PaperTrail::Version.where_object(content: "Hello", title: "Article")
There are two scenarios: diffing adjacent versions and diffing non-adjacent versions.
The best way to diff adjacent versions is to get PaperTrail to do it for you.
If you add an object_changes
text column to your versions
table, either at
installation time with the rails generate paper_trail:install --with-changes
option or manually, PaperTrail will store the changes
diff (excluding any
attributes PaperTrail is ignoring) in each update
version. You can use the
version.changeset
method to retrieve it. For example:
widget = Widget.create :name => 'Bob'
widget.versions.last.changeset
# {
# "name"=>[nil, "Bob"],
# "created_at"=>[nil, 2015-08-10 04:10:40 UTC],
# "updated_at"=>[nil, 2015-08-10 04:10:40 UTC],
# "id"=>[nil, 1]
# }
widget.update_attributes :name => 'Robert'
widget.versions.last.changeset
# {
# "name"=>["Bob", "Robert"],
# "updated_at"=>[2015-08-10 04:13:19 UTC, 2015-08-10 04:13:19 UTC]
# }
widget.destroy
widget.versions.last.changeset
# {}
The object_changes
are only stored for creation and updates, not when an
object is destroyed.
Please be aware that PaperTrail doesn't use diffs internally. When I designed PaperTrail I wanted simplicity and robustness so I decided to make each version of an object self-contained. A version stores all of its object's data, not a diff from the previous version. This means you can delete any version without affecting any other.
To diff non-adjacent versions you'll have to write your own code. These libraries may help:
For diffing two strings:
- htmldiff: expects but doesn't require HTML input and produces HTML output. Works very well but slows down significantly on large (e.g. 5,000 word) inputs.
- differ: expects plain text input and produces plain text/coloured/HTML/any output. Can do character-wise, word-wise, line-wise, or arbitrary-boundary-string-wise diffs. Works very well on non-HTML input.
- diff-lcs: old-school, line-wise diffs.
For diffing two ActiveRecord objects:
- Jeremy Weiskotten's PaperTrail fork: uses ActiveSupport's diff to return an array of hashes of the changes.
- activerecord-diff: rather like ActiveRecord::Dirty but also allows you to specify which columns to compare.
If you wish to selectively record changes for some models but not others you
can opt out of recording changes by passing :save_changes => false
to your
has_paper_trail
method declaration.
Over time your versions
table will grow to an unwieldy size. Because each
version is self-contained (see the Diffing section above for more) you can
simply delete any records you don't want any more. For example:
sql> delete from versions where created_at < 2010-06-01;
PaperTrail::Version.delete_all ["created_at < ?", 1.week.ago]
If your ApplicationController
has a current_user
method, PaperTrail will
attempt to store the value returned by current_user.id
in the version's
whodunnit
column.
You may want PaperTrail to call a different method to find out who is
responsible. To do so, override the user_for_paper_trail
method in your
controller like this:
class ApplicationController
def user_for_paper_trail
logged_in? ? current_member.id : 'Public user' # or whatever
end
end
In a console session you can manually set who is responsible like this:
PaperTrail.whodunnit = 'Andy Stewart'
widget.update_attributes :name => 'Wibble'
widget.versions.last.whodunnit # Andy Stewart
See also: Setting whodunnit in the rails console
Sometimes you want to define who is responsible for a change in a small scope
without overwriting value of PaperTrail.whodunnit
. It is possible to define
the whodunnit
value for an operation inside a block like this:
PaperTrail.whodunnit = 'Andy Stewart'
widget.whodunnit('Lucas Souza') do
widget.update_attributes :name => 'Wibble'
end
widget.versions.last.whodunnit # Lucas Souza
widget.update_attributes :name => 'Clair'
widget.versions.last.whodunnit # Andy Stewart
widget.whodunnit('Ben Atkins') { |w| w.update_attributes :name => 'Beth' } # this syntax also works
widget.versions.last.whodunnit # Ben Atkins
A version's whodunnit
records who changed the object causing the version
to
be stored. Because a version stores the object as it looked before the change
(see the table above), whodunnit
returns who stopped the object looking like
this -- not who made it look like this. Hence whodunnit
is aliased as
terminator
.
To find out who made a version's object look that way, use
version.paper_trail_originator
. And to find out who made a "live" object look
like it does, call paper_trail_originator
on the object.
widget = Widget.find 153 # assume widget has 0 versions
PaperTrail.whodunnit = 'Alice'
widget.update_attributes :name => 'Yankee'
widget..paper_trail_originator # 'Alice'
PaperTrail.whodunnit = 'Bob'
widget.update_attributes :name => 'Zulu'
widget.paper_trail_originator # 'Bob'
first_version, last_version = widget.versions.first, widget.versions.last
first_version.whodunnit # 'Alice'
first_version.paper_trail_originator # nil
first_version.terminator # 'Alice'
last_version.whodunnit # 'Bob'
last_version.paper_trail_originator # 'Alice'
last_version.terminator # 'Bob'
You can specify custom version subclasses with the :class_name
option:
class PostVersion < PaperTrail::Version
# custom behaviour, e.g:
self.table_name = :post_versions
end
class Post < ActiveRecord::Base
has_paper_trail :class_name => 'PostVersion'
end
Unlike ActiveRecord's class_name
, you'll have to supply the complete module path to the class (e.g. Foo::BarVersion
if your class is inside the module Foo
).
- For models which have a lot of versions, storing each model's versions in a separate table can improve the performance of certain database queries.
- Store different version metadata for different models.
If you are using Postgres, you should also define the sequence that your custom version class will use:
class PostVersion < PaperTrail::Version
self.table_name = :post_versions
self.sequence_name = :post_versions_id_seq
end
If you only use custom version classes and don't have a versions
table, you
must let ActiveRecord know that the PaperTrail::Version
class is an
abstract_class
.
# app/models/paper_trail/version.rb
module PaperTrail
class Version < ActiveRecord::Base
include PaperTrail::VersionConcern
self.abstract_class = true
end
end
You can also specify custom names for the versions and version associations.
This is useful if you already have versions
or/and version
methods on your
model. For example:
class Post < ActiveRecord::Base
has_paper_trail :versions => :paper_trail_versions,
:version => :paper_trail_version
# Existing versions method. We don't want to clash.
def versions
...
end
# Existing version method. We don't want to clash.
def version
...
end
end
Experimental Feature: Known Issues: #542, #590. See also: Caveats below.
PaperTrail can restore three types of associations: Has-One, Has-Many, and
Has-Many-Through. In order to do this, you will need to create a
version_associations
table, either at installation time with the rails generate paper_trail:install --with-associations
option or manually. PaperTrail
will store in that table additional information to correlate versions of the
association and versions of the model when the associated record is changed.
When reifying the model, PaperTrail can use this table, together with the
transaction_id
to find the correct version of the association and reify it.
The transaction_id
is a unique id for version records created in the same
transaction. It is used to associate the version of the model and the version of
the association that are created in the same transaction.
To restore Has-One associations as they were at the time, pass option :has_one => true
to reify
. To restore Has-Many and Has-Many-Through associations, use
option :has_many => true
. For example:
class Location < ActiveRecord::Base
belongs_to :treasure
has_paper_trail
end
class Treasure < ActiveRecord::Base
has_one :location
has_paper_trail
end
treasure.amount # 100
treasure.location.latitude # 12.345
treasure.update_attributes :amount => 153
treasure.location.update_attributes :latitude => 54.321
t = treasure.versions.last.reify(:has_one => true)
t.amount # 100
t.location.latitude # 12.345
If the parent and child are updated in one go, PaperTrail can use the
aforementioned transaction_id
to reify the models as they were before the
transaction (instead of before the update to the model).
treasure.amount # 100
treasure.location.latitude # 12.345
Treasure.transaction do
treasure.location.update_attributes :latitude => 54.321
treasure.update_attributes :amount => 153
end
t = treasure.versions.last.reify(:has_one => true)
t.amount # 100
t.location.latitude # 12.345, instead of 54.321
By default, PaperTrail excludes an associated record from the reified parent
model if the associated record exists in the live model but did not exist as at
the time the version was created. This is usually what you want if you just want
to look at the reified version. But if you want to persist it, it would be
better to pass in option :mark_for_destruction => true
so that the associated
record is included and marked for destruction. Note that mark_for_destruction
only has an effect on associations marked with autosave: true
.
class Widget < ActiveRecord::Base
has_paper_trail
has_one :wotsit, autosave: true
end
class Wotsit < ActiveRecord::Base
has_paper_trail
belongs_to :widget
end
widget = Widget.create(:name => 'widget_0')
widget.update_attributes(:name => 'widget_1')
widget.create_wotsit(:name => 'wotsit')
widget_0 = widget.versions.last.reify(:has_one => true)
widget_0.wotsit # nil
widget_0 = widget.versions.last.reify(:has_one => true, :mark_for_destruction => true)
widget_0.wotsit.marked_for_destruction? # true
widget_0.save!
widget.reload.wotsit # nil
Caveats:
- PaperTrail can't restore an association properly if the association record can be updated to replace its parent model (by replacing the foreign key)
- Currently PaperTrail only support single
version_associations
table. The implication is that you can only use a single table to store the versions for all related models. Sorry for those who use multiple version tables. - PaperTrail only reifies the first level of associations, i.e., it does not reify any associations of its associations, and so on.
- PaperTrail relies on the callbacks on the association model (and the :through association model for Has-Many-Through associations) to record the versions and the relationship between the versions. If the association is changed without invoking the callbacks, Reification won't work. Below are some examples:
Given these models:
class Book < ActiveRecord::Base
has_many :authorships, :dependent => :destroy
has_many :authors, :through => :authorships, :source => :person
has_paper_trail
end
class Authorship < ActiveRecord::Base
belongs_to :book
belongs_to :person
has_paper_trail # NOTE
end
class Person < ActiveRecord::Base
has_many :authorships, :dependent => :destroy
has_many :books, :through => :authorships
has_paper_trail
end
Then each of the following will store authorship versions:
@book.authors << @dostoyevsky
@book.authors.create :name => 'Tolstoy'
@book.authorships.last.destroy
@book.authorships.clear
@book.author_ids = [@solzhenistyn.id, @dostoyevsky.id]
But none of these will:
@book.authors.delete @tolstoy
@book.author_ids = []
@book.authors = []
Having said that, you can apparently get all these working (I haven't tested it myself) with this patch:
# In config/initializers/active_record_patch.rb
module ActiveRecord
# = Active Record Has Many Through Association
module Associations
class HasManyThroughAssociation < HasManyAssociation #:nodoc:
alias_method :original_delete_records, :delete_records
def delete_records(records, method)
method ||= :destroy
original_delete_records(records, method)
end
end
end
end
See issue 113 for a discussion about this.
You can store arbitrary model-level metadata alongside each version like this:
class Article < ActiveRecord::Base
belongs_to :author
has_paper_trail :meta => { :author_id => :author_id,
:word_count => :count_words,
:answer => 42 }
def count_words
153
end
end
PaperTrail will call your proc with the current article and store the result in
the author_id
column of the versions
table.
Why would you do this? In this example, author_id
is an attribute of
Article
and PaperTrail will store it anyway in a serialized form in the
object
column of the version
record. But let's say you wanted to pull out
all versions for a particular author; without the metadata you would have to
deserialize (reify) each version
object to see if belonged to the author in
question. Clearly this is inefficient. Using the metadata you can find just
those versions you want:
PaperTrail::Version.where(:author_id => author_id)
You can also store any information you like from your controller. Override
the info_for_paper_trail
method in your controller to return a hash whose keys
correspond to columns in your versions
table.
class ApplicationController
def info_for_paper_trail
{ :ip => request.remote_ip, :user_agent => request.user_agent }
end
end
If you are using rails 3 or the protected_attributes gem you must declare
your metadata columns to be attr_accessible
.
# app/models/paper_trail/version.rb
module PaperTrail
class Version < ActiveRecord::Base
include PaperTrail::VersionConcern
attr_accessible :author_id, :word_count, :answer
end
end
If you're using strong_parameters instead of protected_attributes
then there is no need to use attr_accessible
.
By default, PaperTrail stores your changes as a YAML
dump. You can override
this with the serializer config option:
PaperTrail.serializer = MyCustomSerializer
A valid serializer is a module
(or class
) that defines a load
and dump
method. These serializers are included in the gem for your convenience:
If you use PostgreSQL, and would like to store your object
(and/or
object_changes
) data in a column of type JSON
or type JSONB
, specify
json
instead of text
for these columns in your migration:
create_table :versions do |t|
...
t.json :object # Full object changes
t.json :object_changes # Optional column-level changes
...
end
Note: You don't need to use a particular serializer for the PostgreSQL JSON
column type.
Postgres' alter column
command will not automatically convert a text
column to json
, but it can still be done with plain SQL.
alter table versions
alter column object type json
using object::json;
PaperTrail has a config option that can be used to enable/disable whether
PaperTrail attempts to utilize ActiveRecord
's serialized_attributes
feature.
Note: This is enabled by default when PaperTrail is used with ActiveRecord
version < 4.2
, and disabled by default when used with ActiveRecord 4.2.x
.
Since serialized_attributes
will be removed in ActiveRecord
version 5.0
,
this configuration value has no functionality when PaperTrail is used with
version 5.0
or greater.
# Enable support
PaperTrail.config.serialized_attributes = true
# Disable support
PaperTrail.config.serialized_attributes = false
# Get current setting
PaperTrail.serialized_attributes?
You may want to turn PaperTrail off to speed up your tests. See the Turning
PaperTrail Off/On section above for tips on usage
with Test::Unit
.
PaperTrail provides a helper that works with RSpec to make it easier to
control when PaperTrail
is enabled during testing.
If you wish to use the helper, you will need to require it in your RSpec test helper like so:
# spec/rails_helper.rb
ENV["RAILS_ENV"] ||= 'test'
require 'spec_helper'
require File.expand_path("../../config/environment", __FILE__)
require 'rspec/rails'
...
require 'paper_trail/frameworks/rspec'
When the helper is loaded, PaperTrail will be turned off for all tests by
default. When you wish to enable PaperTrail for a test you can either wrap the
test in a with_versioning
block, or pass in :versioning => true
option to a
spec block, like so:
describe "RSpec test group" do
it 'by default, PaperTrail will be turned off' do
expect(PaperTrail).to_not be_enabled
end
with_versioning do
it 'within a `with_versioning` block it will be turned on' do
expect(PaperTrail).to be_enabled
end
end
it 'can be turned on at the `it` or `describe` level like this', :versioning => true do
expect(PaperTrail).to be_enabled
end
end
The helper will also reset the PaperTrail.whodunnit
value to nil
before each
test to help prevent data spillover between tests. If you are using PaperTrail
with Rails, the helper will automatically set the PaperTrail.controller_info
value to {}
as well, again, to help prevent data spillover between tests.
There is also a be_versioned
matcher provided by PaperTrail's RSpec helper
which can be leveraged like so:
class Widget < ActiveRecord::Base
end
describe Widget do
it "is not versioned by default" do
is_expected.to_not be_versioned
end
describe "add versioning to the `Widget` class" do
before(:all) do
class Widget < ActiveRecord::Base
has_paper_trail
end
end
it "enables paper trail" do
is_expected.to be_versioned
end
end
end
It is also possible to do assertions on the versions using have_a_version_with
matcher
describe '`have_a_version_with` matcher' do
before do
widget.update_attributes!(:name => 'Leonard', :an_integer => 1 )
widget.update_attributes!(:name => 'Tom')
widget.update_attributes!(:name => 'Bob')
end
it "is possible to do assertions on versions" do
expect(widget).to have_a_version_with :name => 'Leonard', :an_integer => 1
expect(widget).to have_a_version_with :an_integer => 1
expect(widget).to have_a_version_with :name => 'Tom'
end
end
PaperTrail provides a helper for Cucumber that works similar to the RSpec helper.If you wish to use the helper, you will need to require in your cucumber helper like so:
# features/support/env.rb
ENV["RAILS_ENV"] ||= "cucumber"
require File.expand_path(File.dirname(__FILE__) + '/../../config/environment')
...
require 'paper_trail/frameworks/cucumber'
When the helper is loaded, PaperTrail will be turned off for all scenarios by a
before
hook added by the helper by default. When you wish to enable PaperTrail
for a scenario, you can wrap code in a with_versioning
block in a step, like
so:
Given /I want versioning on my model/ do
with_versioning do
# PaperTrail will be turned on for all code inside of this block
end
end
The helper will also reset the PaperTrail.whodunnit
value to nil
before each
test to help prevent data spillover between tests. If you are using PaperTrail
with Rails, the helper will automatically set the PaperTrail.controller_info
value to {}
as well, again, to help prevent data spillover between tests.
If you wish to use the RSpec
or Cucumber
helpers with Spork, you will
need to manually require the helper(s) in your prefork
block on your test
helper, like so:
# spec/rails_helper.rb
require 'spork'
Spork.prefork do
# This file is copied to spec/ when you run 'rails generate rspec:install'
ENV["RAILS_ENV"] ||= 'test'
require 'spec_helper'
require File.expand_path("../../config/environment", __FILE__)
require 'rspec/rails'
require 'paper_trail/frameworks/rspec'
require 'paper_trail/frameworks/cucumber'
...
end
If you wish to use the RSpec
or Cucumber
helpers with Zeus or
Spring, you will need to manually require the helper(s) in your test
helper, like so:
# spec/rails_helper.rb
ENV["RAILS_ENV"] ||= 'test'
require 'spec_helper'
require File.expand_path("../../config/environment", __FILE__)
require 'rspec/rails'
require 'paper_trail/frameworks/rspec'
Paper Trail has facilities to test against Postgres, Mysql and SQLite. To switch between DB engines you will need to export the DB variable for the engine you wish to test aganist.
Though be aware we do not have the abilty to create the db's (except sqlite) for you. You can look at .travis.yml before_script for an example of how to create the db's needed.
export DB=postgres
export DB=mysql
export DB=sqlite # this is default
- Jutsu #8 - Version your RoR models with PaperTrail, Thibault, 29th September 2014
- Versioning with PaperTrail, Ilya Bodrov, 10th April 2014
- Using PaperTrail to track stack traces, T James Corcoran's blog, 1st October 2013.
- RailsCast #255 - Undo with Paper Trail, Feb 28, 2011
- RailsCast #255 - Undo with PaperTrail, 28th February 2011.
- Keep a Paper Trail with PaperTrail, Linux Magazine, 16th September 2009.
Please use GitHub's issue tracker.
Many thanks to:
- Dmitry Polushkin
- Russell Osborne
- Zachery Hostens
- Jeremy Weiskotten
- Phan Le
- jdrucza
- conickal
- Thibaud Guillaume-Gentil
- Danny Trelogan
- Mikl Kurkov
- Franco Catena
- Emmanuel Gomez
- Matthew MacLeod
- benzittlau
- Tom Derks
- Jonas Hoglund
- Stefan Huber
- thinkcast
- Dominik Sander
- Burke Libbey
- 6twenty
- nir0
- Eduard Tsech
- Mathieu Arnold
- Nicholas Thrower
- Benjamin Curtis
- Peter Harkins
- Mohd Amree
- Nikita Cernovs
- Jason Noble
- Jared Mehle
- Eric Schwartz
- Ben Woosley
- Philip Arndt
- Daniel Vydra
- Byron Bowerman
- Nicolas Buduroi
- Pikender Sharma
- Paul Brannan
- Ben Morrall
- Yves Senn
- Ben Atkins
- Tyler Rick
- Bradley Priest
- David Butler
- Paul Belt
- Vlad Bokov
- Sean Marcia
- Chulki Lee
- Lucas Souza
- Russell Osborne
- Ben Li
- Felix Liu
Copyright (c) 2011 Andy Stewart ([email protected]). Released under the MIT licence.