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spec | ||
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.document | ||
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aasm.gemspec | ||
API | ||
Appraisals | ||
CHANGELOG.md | ||
CODE_OF_CONDUCT.md | ||
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HOWTO | ||
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README.md | ||
README_FROM_VERSION_3_TO_4.md | ||
TESTING.md |
AASM - Ruby state machines
Index
- Upgrade from version 3 to 4
- Usage
- Callbacks
- Guards
- Transitions
- Multiple state machines per class
- Auto-generated Status Constants
- Extending AASM
- ActiveRecord
- Bang events
- Timestamps
- ActiveRecord enums
- Sequel
- Dynamoid
- Mongoid
- Nobrainer
- Redis
- Automatic Scopes
- Transaction support
- Pessimistic Locking
- Column name & migration
- Log State Changes
- Inspection
- Warning output
- RubyMotion support
- Testing
- Installation
- Generators
- Test suite with Docker
- Latest changes
- Questions?
- Maintainers
- Contributing
- Warranty
- License
This package contains AASM, a library for adding finite state machines to Ruby classes.
AASM started as the acts_as_state_machine plugin but has evolved into a more generic library that no longer targets only ActiveRecord models. It currently provides adapters for many ORMs but it can be used for any Ruby class, no matter what parent class it has (if any).
Upgrade from version 3 to 4
Take a look at the README_FROM_VERSION_3_TO_4 for details how to switch from version 3.x to 4.0 of AASM.
Usage
Adding a state machine is as simple as including the AASM module and start defining states and events together with their transitions:
class Job
include AASM
aasm do
state :sleeping, initial: true
state :running, :cleaning
event :run do
transitions from: :sleeping, to: :running
end
event :clean do
transitions from: :running, to: :cleaning
end
event :sleep do
transitions from: [:running, :cleaning], to: :sleeping
end
end
end
This provides you with a couple of public methods for instances of the class Job
:
job = Job.new
job.sleeping? # => true
job.may_run? # => true
job.run
job.running? # => true
job.sleeping? # => false
job.may_run? # => false
job.run # => raises AASM::InvalidTransition
If you don't like exceptions and prefer a simple true
or false
as response, tell
AASM not to be whiny:
class Job
...
aasm whiny_transitions: false do
...
end
end
job.running? # => true
job.may_run? # => false
job.run # => false
When firing an event, you can pass a block to the method, it will be called only if the transition succeeds :
job.run do
job.user.notify_job_ran # Will be called if job.may_run? is true
end
Callbacks
You can define a number of callbacks for your events, transitions and states. These methods, Procs or classes will be called when certain criteria are met, like entering a particular state:
class Job
include AASM
aasm do
state :sleeping, initial: true, before_enter: :do_something
state :running, before_enter: Proc.new { do_something && notify_somebody }
state :finished
after_all_transitions :log_status_change
event :run, after: :notify_somebody do
before do
log('Preparing to run')
end
transitions from: :sleeping, to: :running, after: Proc.new {|*args| set_process(*args) }
transitions from: :running, to: :finished, after: LogRunTime
end
event :sleep do
after do
...
end
error do |e|
...
end
transitions from: :running, to: :sleeping
end
end
def log_status_change
puts "changing from #{aasm.from_state} to #{aasm.to_state} (event: #{aasm.current_event})"
end
def set_process(name)
...
end
def do_something
...
end
def notify_somebody
...
end
end
class LogRunTime
def call
log "Job was running for X seconds"
end
end
In this case do_something
is called before actually entering the state sleeping
,
while notify_somebody
is called after the transition run
(from sleeping
to running
)
is finished.
AASM will also initialize LogRunTime
and run the call
method for you after the transition from running
to finished
in the example above. You can pass arguments to the class by defining an initialize method on it, like this:
Note that Procs are executed in the context of a record, it means that you don't need to expect the record as an argument, just call the methods you need.
class LogRunTime
# optional args parameter can be omitted, but if you define initialize
# you must accept the model instance as the first parameter to it.
def initialize(job, args = {})
@job = job
end
def call
log "Job was running for #{@job.run_time} seconds"
end
end
Parameters
You can pass parameters to events:
job = Job.new
job.run(:defragmentation)
All guards and after callbacks will receive these parameters. In this case set_process
would be called with
:defragmentation
argument.
If the first argument to the event is a state (e.g. :running
or :finished
), the first argument is consumed and
the state machine will attempt to transition to that state. Add comma separated parameter for gaurds and callbacks
job = Job.new
job.run(:running, :defragmentation)
In this case set_process
won't be called, job will transition to running state and callback will receive
:defragmentation as parameter
Error Handling
In case of an error during the event processing the error is rescued and passed to :error
callback, which can handle it or re-raise it for further propagation.
Also, you can define a method that will be called if any event fails:
def aasm_event_failed(event_name, old_state_name)
# use custom exception/messages, report metrics, etc
end
During the transition's :after
callback (and reliably only then, or in the global
after_all_transitions
callback) you can access the originating state (the from-state)
and the target state (the to state), like this:
def set_process(name)
logger.info "from #{aasm.from_state} to #{aasm.to_state}"
end
Lifecycle
Here you can see a list of all possible callbacks, together with their order of calling:
begin
event before_all_events
event before
event guards
transition guards
old_state before_exit
old_state exit
after_all_transitions
transition after
new_state before_enter
new_state enter
...update state...
event before_success # if persist successful
transition success # if persist successful, database update not guaranteed
event success # if persist successful, database update not guaranteed
old_state after_exit
new_state after_enter
event after
event after_all_events
rescue
event error
event error_on_all_events
ensure
event ensure
event ensure_on_all_events
end
Use event's after_commit
callback if it should be fired after database update.
The current event triggered
While running the callbacks you can easily retrieve the name of the event triggered
by using aasm.current_event
:
# taken the example callback from above
def do_something
puts "triggered #{aasm.current_event}"
end
and then
job = Job.new
# without bang
job.sleep # => triggered :sleep
# with bang
job.sleep! # => triggered :sleep!
Guards
Let's assume you want to allow particular transitions only if a defined condition is
given. For this you can set up a guard per transition, which will run before actually
running the transition. If the guard returns false
the transition will be
denied (raising AASM::InvalidTransition
):
class Cleaner
include AASM
aasm do
state :idle, initial: true
state :cleaning
event :clean do
transitions from: :idle, to: :cleaning, guard: :cleaning_needed?
end
event :clean_if_needed do
transitions from: :idle, to: :cleaning do
guard do
cleaning_needed?
end
end
transitions from: :idle, to: :idle
end
event :clean_if_dirty do
transitions from: :idle, to: :cleaning, guard: :if_dirty?
end
end
def cleaning_needed?
false
end
def if_dirty?(status)
status == :dirty
end
end
job = Cleaner.new
job.may_clean? # => false
job.clean # => raises AASM::InvalidTransition
job.may_clean_if_needed? # => true
job.clean_if_needed! # idle
job.clean_if_dirty(:clean) # => raises AASM::InvalidTransition
job.clean_if_dirty(:dirty) # => true
You can even provide a number of guards, which all have to succeed to proceed
def walked_the_dog?; ...; end
event :sleep do
transitions from: :running, to: :sleeping, guards: [:cleaning_needed?, :walked_the_dog?]
end
If you want to provide guards for all transitions within an event, you can use event guards
event :sleep, guards: [:walked_the_dog?] do
transitions from: :running, to: :sleeping, guards: [:cleaning_needed?]
transitions from: :cleaning, to: :sleeping
end
If you prefer a more Ruby-like guard syntax, you can use if
and unless
as well:
event :clean do
transitions from: :running, to: :cleaning, if: :cleaning_needed?
end
event :sleep do
transitions from: :running, to: :sleeping, unless: :cleaning_needed?
end
end
You can invoke a Class instead of a method if the Class responds to call
event :sleep do
transitions from: :running, to: :sleeping, guards: Dog
end
class Dog
def call
cleaning_needed? && walked?
end
...
end
Transitions
In the event of having multiple transitions for an event, the first transition that successfully completes will stop other transitions in the same event from being processed.
require 'aasm'
class Job
include AASM
aasm do
state :stage1, initial: true
state :stage2
state :stage3
state :completed
event :stage1_completed do
transitions from: :stage1, to: :stage3, guard: :stage2_completed?
transitions from: :stage1, to: :stage2
end
end
def stage2_completed?
true
end
end
job = Job.new
job.stage1_completed
job.aasm.current_state # stage3
You can define transition from any defined state by omitting from
:
event :abort do
transitions to: :aborted
end
Display name for state
You can define display name for state using :display option
class Job
include AASM
aasm do
state :stage1, initial: true, display: 'First Stage'
state :stage2
state :stage3
end
end
job = Job.new
job.aasm.human_state
Multiple state machines per class
Multiple state machines per class are supported. Be aware though that AASM has been
built with one state machine per class in mind. Nonetheless, here's how to do it (see below). Please note that you will need to specify database columns for where your pertinent states will be stored - we have specified two columns move_state
and work_state
in the example below. See the Column name & migration section for further info.
class SimpleMultipleExample
include AASM
aasm(:move, column: 'move_state') do
state :standing, initial: true
state :walking
state :running
event :walk do
transitions from: :standing, to: :walking
end
event :run do
transitions from: [:standing, :walking], to: :running
end
event :hold do
transitions from: [:walking, :running], to: :standing
end
end
aasm(:work, column: 'work_state') do
state :sleeping, initial: true
state :processing
event :start do
transitions from: :sleeping, to: :processing
end
event :stop do
transitions from: :processing, to: :sleeping
end
end
end
simple = SimpleMultipleExample.new
simple.aasm(:move).current_state
# => :standing
simple.aasm(:work).current_state
# => :sleeping
simple.start
simple.aasm(:move).current_state
# => :standing
simple.aasm(:work).current_state
# => :processing
Handling naming conflicts between multiple state machines
AASM doesn't prohibit to define the same event in more than one state
machine. If no namespace is provided, the latest definition "wins" and
overrides previous definitions. Nonetheless, a warning is issued:
SimpleMultipleExample: overriding method 'run'!
.
Alternatively, you can provide a namespace for each state machine:
class NamespacedMultipleExample
include AASM
aasm(:status) do
state :unapproved, initial: true
state :approved
event :approve do
transitions from: :unapproved, to: :approved
end
event :unapprove do
transitions from: :approved, to: :unapproved
end
end
aasm(:review_status, namespace: :review) do
state :unapproved, initial: true
state :approved
event :approve do
transitions from: :unapproved, to: :approved
end
event :unapprove do
transitions from: :approved, to: :unapproved
end
end
end
namespaced = NamespacedMultipleExample.new
namespaced.aasm(:status).current_state
# => :unapproved
namespaced.aasm(:review_status).current_state
# => :unapproved
namespaced.approve_review
namespaced.aasm(:review_status).current_state
# => :approved
All AASM class- and instance-level aasm
methods accept a state machine selector.
So, for example, to use inspection on a class level, you have to use
SimpleMultipleExample.aasm(:move).states.map(&:name)
# => [:standing, :walking, :running]
Binding event
Allow an event to be bound to another
class Example
include AASM
aasm(:work) do
state :sleeping, initial: true
state :processing
event :start do
transitions from: :sleeping, to: :processing
end
event :stop do
transitions from: :processing, to: :sleeping
end
end
aasm(:question) do
state :answered, initial: true
state :asked
event :ask, binding_event: :start do
transitions from: :answered, to: :asked
end
event :answer, binding_event: :stop do
transitions from: :asked, to: :answered
end
end
end
example = Example.new
example.aasm(:work).current_state #=> :sleeping
example.aasm(:question).current_state #=> :answered
example.ask
example.aasm(:work).current_state #=> :processing
example.aasm(:question).current_state #=> :asked
Auto-generated Status Constants
AASM automatically generates constants for each status so you don't have to explicitly define them.
class Foo
include AASM
aasm do
state :initialized
state :calculated
state :finalized
end
end
> Foo::STATE_INITIALIZED
#=> :initialized
> Foo::STATE_CALCULATED
#=> :calculated
Extending AASM
AASM allows you to easily extend AASM::Base
for your own application purposes.
Let's suppose we have common logic across many AASM models. We can embody this logic in a sub-class of AASM::Base
.
class CustomAASMBase < AASM::Base
# A custom transiton that we want available across many AASM models.
def count_transitions!
klass.class_eval do
aasm with_klass: CustomAASMBase do
after_all_transitions :increment_transition_count
end
end
end
# A custom annotation that we want available across many AASM models.
def requires_guards!
klass.class_eval do
attr_reader :authorizable_called,
:transition_count,
:fillable_called
def authorizable?
@authorizable_called = true
end
def fillable?
@fillable_called = true
end
def increment_transition_count
@transition_count ||= 0
@transition_count += 1
end
end
end
end
When we declare our model that has an AASM state machine, we simply declare the AASM block with a :with_klass
key to our own class.
class SimpleCustomExample
include AASM
# Let's build an AASM state machine with our custom class.
aasm with_klass: CustomAASMBase do
requires_guards!
count_transitions!
state :initialised, initial: true
state :filled_out
state :authorised
event :fill_out do
transitions from: :initialised, to: :filled_out, guard: :fillable?
end
event :authorise do
transitions from: :filled_out, to: :authorised, guard: :authorizable?
end
end
end
ActiveRecord
AASM comes with support for ActiveRecord and allows automatic persisting of the object's state in the database.
Add gem 'after_commit_everywhere', '~> 1.0'
to your Gemfile.
class Job < ActiveRecord::Base
include AASM
aasm do # default column: aasm_state
state :sleeping, initial: true
state :running
event :run do
transitions from: :sleeping, to: :running
end
event :sleep do
transitions from: :running, to: :sleeping
end
end
end
Bang events
You can tell AASM to auto-save the object or leave it unsaved
job = Job.new
job.run # not saved
job.run! # saved
# or
job.aasm.fire(:run) # not saved
job.aasm.fire!(:run) # saved
Saving includes running all validations on the Job
class. If
whiny_persistence
flag is set to true
, exception is raised in case of
failure. If whiny_persistence
flag is set to false, methods with a bang return
true
if the state transition is successful or false
if an error occurs.
If you want make sure the state gets saved without running validations (and
thereby maybe persisting an invalid object state), simply tell AASM to skip the
validations. Be aware that when skipping validations, only the state column will
be updated in the database (just like ActiveRecord update_column
is working).
class Job < ActiveRecord::Base
include AASM
aasm skip_validation_on_save: true do
state :sleeping, initial: true
state :running
event :run do
transitions from: :sleeping, to: :running
end
event :sleep do
transitions from: :running, to: :sleeping
end
end
end
Also You can skip the validation at instance level with some_event_name_without_validation!
method.
With this you have the flexibility of having validation for all your transitions by default and then skip it wherever required.
Please note that only state column will be updated as mentioned in the above example.
job.run_without_validation!
If you want to make sure that the AASM column for storing the state is not directly assigned, configure AASM to not allow direct assignment, like this:
class Job < ActiveRecord::Base
include AASM
aasm no_direct_assignment: true do
state :sleeping, initial: true
state :running
event :run do
transitions from: :sleeping, to: :running
end
end
end
resulting in this:
job = Job.create
job.aasm_state # => 'sleeping'
job.aasm_state = :running # => raises AASM::NoDirectAssignmentError
job.aasm_state # => 'sleeping'
Timestamps
You can tell AASM to try to write a timestamp whenever a new state is entered.
If timestamps: true
is set, AASM will look for a field named like the new state plus _at
and try to fill it:
class Job < ActiveRecord::Base
include AASM
aasm timestamps: true do
state :sleeping, initial: true
state :running
event :run do
transitions from: :sleeping, to: :running
end
end
end
resulting in this:
job = Job.create
job.running_at # => nil
job.run!
job.running_at # => 2020-02-20 20:00:00
Missing timestamp fields are silently ignored, so it is not necessary to have setters (such as ActiveRecord columns) for all states when using this option.
ActiveRecord enums
You can use enumerations in Rails 4.1+ for your state column:
class Job < ActiveRecord::Base
include AASM
enum state: {
sleeping: 5,
running: 99
}
aasm column: :state, enum: true do
state :sleeping, initial: true
state :running
end
end
You can explicitly pass the name of the method which provides access
to the enumeration mapping as a value of enum
, or you can simply
set it to true
. In the latter case AASM will try to use
pluralized column name to access possible enum states.
Furthermore, if your column has integer type (which is normally the
case when you're working with Rails enums), you can omit :enum
setting --- AASM auto-detects this situation and enabled enum
support. If anything goes wrong, you can disable enum functionality
and fall back to the default behavior by setting :enum
to false
.
Sequel
AASM also supports Sequel besides ActiveRecord, and Mongoid.
class Job < Sequel::Model
include AASM
aasm do # default column: aasm_state
...
end
end
However it's not yet as feature complete as ActiveRecord. For example, there are scopes defined yet. See Automatic Scopes.
Dynamoid
Since version 4.8.0
AASM also supports Dynamoid as
persistence ORM.
Mongoid
AASM also supports persistence to Mongodb if you're using Mongoid. Make sure to include Mongoid::Document before you include AASM.
class Job
include Mongoid::Document
include AASM
field :aasm_state
aasm do
...
end
end
NoBrainer
AASM also supports persistence to RethinkDB if you're using Nobrainer. Make sure to include NoBrainer::Document before you include AASM.
class Job
include NoBrainer::Document
include AASM
field :aasm_state
aasm do
...
end
end
Redis
AASM also supports persistence in Redis via Redis::Objects. Make sure to include Redis::Objects before you include AASM. Note that non-bang events will work as bang events, persisting the changes on every call.
class User
include Redis::Objects
include AASM
aasm do
end
end
Automatic Scopes
AASM will automatically create scope methods for each state in the model.
class Job < ActiveRecord::Base
include AASM
aasm do
state :sleeping, initial: true
state :running
state :cleaning
end
def self.sleeping
"This method name is already in use"
end
end
class JobsController < ApplicationController
def index
@running_jobs = Job.running
@recent_cleaning_jobs = Job.cleaning.where('created_at >= ?', 3.days.ago)
# @sleeping_jobs = Job.sleeping #=> "This method name is already in use"
end
end
If you don't need scopes (or simply don't want them), disable their creation when
defining the AASM
states, like this:
class Job < ActiveRecord::Base
include AASM
aasm create_scopes: false do
state :sleeping, initial: true
state :running
state :cleaning
end
end
Transaction support
Since version 3.0.13 AASM supports ActiveRecord transactions. So whenever a transition callback or the state update fails, all changes to any database record are rolled back. Mongodb does not support transactions.
There are currently 3 transactional callbacks that can be handled on the event, and 2 transactional callbacks for all events.
event before_all_transactions
event before_transaction
event aasm_fire_event (within transaction)
event after_commit (if event successful)
event after_transaction
event after_all_transactions
If you want to make sure a depending action happens only after the transaction is committed,
use the after_commit
callback along with the auto-save (bang) methods, like this:
class Job < ActiveRecord::Base
include AASM
aasm do
state :sleeping, initial: true
state :running
event :run, after_commit: :notify_about_running_job do
transitions from: :sleeping, to: :running
end
end
def notify_about_running_job
...
end
end
job = Job.where(state: 'sleeping').first!
job.run! # Saves the model and triggers the after_commit callback
Note that the following will not run the after_commit
callbacks because
the auto-save method is not used:
job = Job.where(state: 'sleeping').first!
job.run
job.save! #notify_about_running_job is not run
Please note that :after_commit
AASM callbacks behaves around custom implementation
of transaction pattern rather than a real-life DB transaction. This fact still causes
the race conditions and redundant callback calls within nested transaction. In order
to fix that it's highly recommended to add gem 'after_commit_everywhere', '~> 1.0'
to your Gemfile
.
If you want to encapsulate state changes within an own transaction, the behavior
of this nested transaction might be confusing. Take a look at
ActiveRecord Nested Transactions
if you want to know more about this. Nevertheless, AASM by default requires a new transaction
transaction(requires_new: true)
. You can override this behavior by changing
the configuration
class Job < ActiveRecord::Base
include AASM
aasm requires_new_transaction: false do
...
end
...
end
which then leads to transaction(requires_new: false)
, the Rails default.
Additionally, if you do not want any of your ActiveRecord actions to be
wrapped in a transaction, you can specify the use_transactions
flag. This can
be useful if you want want to persist things to the database that happen as a
result of a transaction or callback, even when some error occurs. The
use_transactions
flag is true by default.
class Job < ActiveRecord::Base
include AASM
aasm use_transactions: false do
...
end
...
end
Pessimistic Locking
AASM supports ActiveRecord pessimistic locking via with_lock
for database persistence layers.
Option | Purpose |
---|---|
false (default) |
No lock is obtained |
true |
Obtain a blocking pessimistic lock e.g. FOR UPDATE |
String | Obtain a lock based on the SQL string e.g. FOR UPDATE NOWAIT |
class Job < ActiveRecord::Base
include AASM
aasm requires_lock: true do
...
end
...
end
class Job < ActiveRecord::Base
include AASM
aasm requires_lock: 'FOR UPDATE NOWAIT' do
...
end
...
end
Column name & migration
As a default AASM uses the column aasm_state
to store the states. You can override
this by defining your favorite column name, using :column
like this:
class Job < ActiveRecord::Base
include AASM
aasm column: :my_state do
...
end
aasm :another_state_machine, column: :second_state do
...
end
end
Whatever column name is used, make sure to add a migration to provide this column
(of type string
).
Do not add default value for column at the database level. If you add default
value in database then AASM callbacks on the initial state will not be fired upon
instantiation of the model.
class AddJobState < ActiveRecord::Migration
def self.up
add_column :jobs, :aasm_state, :string
end
def self.down
remove_column :jobs, :aasm_state
end
end
Log State Changes
Logging state change can be done using paper_trail gem
Example of implementation can be found here https://github.com/nitsujri/aasm-papertrail-example
Inspection
AASM supports query methods for states and events
Given the following Job
class:
class Job
include AASM
aasm do
state :sleeping, initial: true
state :running, :cleaning
event :run do
transitions from: :sleeping, to: :running
end
event :clean do
transitions from: :running, to: :cleaning, guard: :cleaning_needed?
end
event :sleep do
transitions from: [:running, :cleaning], to: :sleeping
end
end
def cleaning_needed?
false
end
end
# show all states
Job.aasm.states.map(&:name)
#=> [:sleeping, :running, :cleaning]
job = Job.new
# show all permitted states (from initial state)
job.aasm.states(permitted: true).map(&:name)
#=> [:running]
# List all the permitted transitions(event and state pairs) from initial state
job.aasm.permitted_transitions
#=> [{ :event => :run, :state => :running }]
job.run
job.aasm.states(permitted: true).map(&:name)
#=> [:sleeping]
# show all non permitted states
job.aasm.states(permitted: false).map(&:name)
#=> [:cleaning]
# show all possible (triggerable) events from the current state
job.aasm.events.map(&:name)
#=> [:clean, :sleep]
# show all permitted events
job.aasm.events(permitted: true).map(&:name)
#=> [:sleep]
# show all non permitted events
job.aasm.events(permitted: false).map(&:name)
#=> [:clean]
# show all possible events except a specific one
job.aasm.events(reject: :sleep).map(&:name)
#=> [:clean]
# list states for select
Job.aasm.states_for_select
#=> [["Sleeping", "sleeping"], ["Running", "running"], ["Cleaning", "cleaning"]]
# show permitted states with guard parameter
job.aasm.states({permitted: true}, guard_parameter).map(&:name)
Warning output
Warnings are by default printed to STDERR
. If you want to log those warnings to another output,
use
class Job
include AASM
aasm logger: Rails.logger do
...
end
end
You can hide warnings by setting AASM::Configuration.hide_warnings = true
RubyMotion support
Now supports CodeDataQuery ! However I'm still in the process of submitting my compatibility updates to their repository. In the meantime you can use my fork, there may still be some minor issues but I intend to extensively use it myself, so fixes should come fast.
Warnings:
- Due to RubyMotion Proc's lack of 'source_location' method, it may be harder to find out the origin of a "cannot transition from" error. I would recommend using the 'instance method symbol / string' way whenever possible when defining guardians and callbacks.
Testing
RSpec
AASM provides some matchers for RSpec:
transition_from
,have_state
,allow_event
- and
allow_transition_to
.
Installation Instructions:
- Add
require 'aasm/rspec'
to yourspec_helper.rb
file.
Examples Of Usage in Rspec:
# classes with only the default state machine
job = Job.new
expect(job).to transition_from(:sleeping).to(:running).on_event(:run)
expect(job).not_to transition_from(:sleeping).to(:cleaning).on_event(:run)
expect(job).to have_state(:sleeping)
expect(job).not_to have_state(:running)
expect(job).to allow_event :run
expect(job).to_not allow_event :clean
expect(job).to allow_transition_to(:running)
expect(job).to_not allow_transition_to(:cleaning)
# on_event also accept multiple arguments
expect(job).to transition_from(:sleeping).to(:running).on_event(:run, :defragmentation)
# classes with multiple state machine
multiple = SimpleMultipleExample.new
expect(multiple).to transition_from(:standing).to(:walking).on_event(:walk).on(:move)
expect(multiple).to_not transition_from(:standing).to(:running).on_event(:walk).on(:move)
expect(multiple).to have_state(:standing).on(:move)
expect(multiple).not_to have_state(:walking).on(:move)
expect(multiple).to allow_event(:walk).on(:move)
expect(multiple).to_not allow_event(:hold).on(:move)
expect(multiple).to allow_transition_to(:walking).on(:move)
expect(multiple).to_not allow_transition_to(:running).on(:move)
expect(multiple).to transition_from(:sleeping).to(:processing).on_event(:start).on(:work)
expect(multiple).to_not transition_from(:sleeping).to(:sleeping).on_event(:start).on(:work)
expect(multiple).to have_state(:sleeping).on(:work)
expect(multiple).not_to have_state(:processing).on(:work)
expect(multiple).to allow_event(:start).on(:move)
expect(multiple).to_not allow_event(:stop).on(:move)
expect(multiple).to allow_transition_to(:processing).on(:move)
expect(multiple).to_not allow_transition_to(:sleeping).on(:move)
# allow_event also accepts arguments
expect(job).to allow_event(:run).with(:defragmentation)
Minitest
AASM provides assertions and rspec-like expectations for Minitest.
Assertions
List of supported assertions: assert_have_state
, refute_have_state
, assert_transitions_from
, refute_transitions_from
, assert_event_allowed
, refute_event_allowed
, assert_transition_to_allowed
, refute_transition_to_allowed
.
Examples Of Usage (Minitest):
Add require 'aasm/minitest'
to your test_helper.rb
file and use them like this:
# classes with only the default state machine
job = Job.new
assert_transitions_from job, :sleeping, to: :running, on_event: :run
refute_transitions_from job, :sleeping, to: :cleaning, on_event: :run
assert_have_state job, :sleeping
refute_have_state job, :running
assert_event_allowed job, :run
refute_event_allowed job, :clean
assert_transition_to_allowed job, :running
refute_transition_to_allowed job, :cleaning
# on_event also accept arguments
assert_transitions_from job, :sleeping, :defragmentation, to: :running, on_event: :run
# classes with multiple state machine
multiple = SimpleMultipleExample.new
assert_transitions_from multiple, :standing, to: :walking, on_event: :walk, on: :move
refute_transitions_from multiple, :standing, to: :running, on_event: :walk, on: :move
assert_have_state multiple, :standing, on: :move
refute_have_state multiple, :walking, on: :move
assert_event_allowed multiple, :walk, on: :move
refute_event_allowed multiple, :hold, on: :move
assert_transition_to_allowed multiple, :walking, on: :move
refute_transition_to_allowed multiple, :running, on: :move
assert_transitions_from multiple, :sleeping, to: :processing, on_event: :start, on: :work
refute_transitions_from multiple, :sleeping, to: :sleeping, on_event: :start, on: :work
assert_have_state multiple, :sleeping, on: :work
refute_have_state multiple, :processing, on: :work
assert_event_allowed multiple, :start, on: :move
refute_event_allowed multiple, :stop, on: :move
assert_transition_to_allowed multiple, :processing, on: :move
refute_transition_to_allowed multiple, :sleeping, on: :move
Expectations
List of supported expectations: must_transition_from
, wont_transition_from
, must_have_state
, wont_have_state
, must_allow_event
, wont_allow_event
, must_allow_transition_to
, wont_allow_transition_to
.
Add require 'aasm/minitest_spec'
to your test_helper.rb
file and use them like this:
# classes with only the default state machine
job = Job.new
job.must_transition_from :sleeping, to: :running, on_event: :run
job.wont_transition_from :sleeping, to: :cleaning, on_event: :run
job.must_have_state :sleeping
job.wont_have_state :running
job.must_allow_event :run
job.wont_allow_event :clean
job.must_allow_transition_to :running
job.wont_allow_transition_to :cleaning
# on_event also accept arguments
job.must_transition_from :sleeping, :defragmentation, to: :running, on_event: :run
# classes with multiple state machine
multiple = SimpleMultipleExample.new
multiple.must_transition_from :standing, to: :walking, on_event: :walk, on: :move
multiple.wont_transition_from :standing, to: :running, on_event: :walk, on: :move
multiple.must_have_state :standing, on: :move
multiple.wont_have_state :walking, on: :move
multiple.must_allow_event :walk, on: :move
multiple.wont_allow_event :hold, on: :move
multiple.must_allow_transition_to :walking, on: :move
multiple.wont_allow_transition_to :running, on: :move
multiple.must_transition_from :sleeping, to: :processing, on_event: :start, on: :work
multiple.wont_transition_from :sleeping, to: :sleeping, on_event: :start, on: :work
multiple.must_have_state :sleeping, on: :work
multiple.wont_have_state :processing, on: :work
multiple.must_allow_event :start, on: :move
multiple.wont_allow_event :stop, on: :move
multiple.must_allow_transition_to :processing, on: :move
multiple.wont_allow_transition_to :sleeping, on: :move
Installation
Manually from RubyGems.org
% gem install aasm
Or if you are using Bundler
# Gemfile
gem 'aasm'
Building your own gems
% rake build
% sudo gem install pkg/aasm-x.y.z.gem
Generators
After installing AASM you can run generator:
% rails generate aasm NAME [COLUMN_NAME]
Replace NAME with the Model name, COLUMN_NAME is optional(default is 'aasm_state'). This will create a model (if one does not exist) and configure it with aasm block. For ActiveRecord orm a migration file is added to add aasm state column to table.
Docker
Run test suite easily on docker
1. docker-compose build aasm
2. docker-compose run --rm aasm
Latest changes
Take a look at the CHANGELOG for details about recent changes to the current version.
Questions?
Feel free to
- create an issue on GitHub
- ask a question on StackOverflow (tag with
aasm
) - send us a tweet @aasm
Maintainers
- Scott Barron (2006–2009, original author)
- Travis Tilley (2009–2011)
- Thorsten Böttger (since 2011)
- Anil Maurya (since 2016)
Stargazers over time
Contributing
Warranty
This software is provided "as is" and without any express or implied warranties, including, without limitation, the implied warranties of merchantibility and fitness for a particular purpose.
License
Copyright (c) 2006-2017 Scott Barron
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.