mariuszzak / aasm_light

Basic implementation of AASM gem. Just for fun ;)

AasmLight

Welcome to your new gem! In this directory, you'll find the files you need to be able to package up your Ruby library into a gem. Put your Ruby code in the file lib/aasm_light. To experiment with that code, run bin/console for an interactive prompt.

TODO: Delete this and the text above, and describe your gem

Installation

Add this line to your application's Gemfile:

gem 'aasm_light'

And then execute:

$ bundle

Or install it yourself as:

$ gem install aasm_light

Usage

Adding a state machine is as simple as including the AasmLight module and start defining states and events together with their transitions:

class Job
  include AasmLight

  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

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/Mariusz Zak/aasm_light.