ActiveRecord/Rails Integration for the Workflow library
Major+minor versions of workflow-activerecord are based on the oldest
compatible ActiveRecord API. To use workflow with
Rails/ActiveRecord 6., 7. please use:
gem 'workflow-ac
8000
tiverecord', '~> 6.0'
This will also automatically include the newest compatible version of the core 'workflow' gem. But you can also choose a specific version:
gem 'workflow', '~> 2.0'
gem 'workflow-activerecord', '~> 4.1'
Please also have a look at the sample application!
For detailed introduction into workflow DSL please read the
workflow README!
Workflow library can handle the state persistence fully automatically. You
only need to define a string field on the table called workflow_state
and include the workflow mixin in your model class as usual:
class Order < ApplicationRecord
include WorkflowActiverecord
workflow do
# list states and transitions here
end
end
On a database record loading all the state check methods e.g.
article.state, article.awaiting_review? are immediately available.
For new records or if the workflow_state field is not set the state
defaults to the first state declared in the workflow specification. In
our example it is :new, so Article.new.new? returns true and
Article.new.approved? returns false.
At the end of a successful state transition like article.approve! the
new state is immediately saved in the database.
You can change this behaviour by overriding persist_workflow_state
method.
Workflow library also adds automatically generated scopes with names based on states names:
class Order < ApplicationRecord
include WorkflowActiverecord
workflow do
state :approved
state :pending
end
end
# returns all orders with `approved` state
Order.with_approved_state
# returns all orders with `pending` state
Order.with_pending_state
meuble contributed a solution for using custom persistence column easily, e.g. for a legacy database schema:
class LegacyOrder < ApplicationRecord
include WorkflowActiverecord
workflow_column :foo_bar # use this legacy database column for
# persistence
end
Single table inheritance is also supported. Descendant classes can either inherit the workflow definition from the parent or override with its own definition.
Other adapters (such as a custom ActiveRecord plugin) can be selected by adding a workflow_adapter class method, eg.
class Example < ApplicationRecord
def self.workflow_adapter
MyCustomAdapter
end
include Workflow
# ...
end(The above will include MyCustomAdapter instead of the default
WorkflowActiverecord adapter.)
I am frequently asked if it's possible to represent multiple "workflows" in an ActiveRecord class.
The solution depends on your business logic and how you want to structure your implementation.
One solution can be to do it on the class level and use a class
hierarchy. You can use single table inheritance so there is only
single orders table in the database. Read more in the chapter "Single
Table Inheritance" of the ActiveRecord documentation.
Then you define your different classes:
class Order < ActiveRecord::Base
include WorkflowActiverecord
end
class SmallOrder < Order
workflow do
# workflow definition for small orders goes here
end
end
class BigOrder < Order
workflow do
# workflow for big orders, probably with a longer approval chain
end
end
Another solution would be to connect different workflows to object instances via metaclass, e.g.
# Load an object from the database
booking = Booking.find(1234)
# Now define a workflow - exclusively for this object,
# probably depending on some condition or database field
if # some condition
class << booking
include WorkflowActiverecord
workflow do
state :state1
state :state2
end
end
# if some other condition, use a different workflow
You can also encapsulate this in a class method or even put in some ActiveRecord callback. Please also have a look at the full working example!
You can have a look at an advanced on_transition example in
this test file.
You might want to perform the state transition in a database transaction, so that the state is persisted atomically with all the other attributes. To do so, define a module:
module TransitionTransaction
def process_event!(name, *, **)
transaction { super(name, *, **) }
end
endand then prepend it in your model:
class Task
workflow do
...
end
prepend TransitionTransaction
end- GH-14 retire Ruby 2.6 and Rails 5.* and older since they have reached end of live; please use workflow-activerecord 4.1.9, if you still depend on those versions
- GH-13 Switch CI (continuous integration) from travis-CI to GitHub
- Tested Rails 7.0 support
http://github.com/geekq/workflow-activerecord/issues
Author: Vladimir Dobriakov, https://infrastructure-as-code.de
Copyright (c) 2010-2024 Vladimir Dobriakov and Contributors
Copyright (c) 2008-2009 Vodafone
Copyright (c) 2007-2008 Ryan Allen, FlashDen Pty Ltd
Based on the work of Ryan Allen and Scott Barron
Licensed under MIT license, see the LICENSE file.