Koine::CommandBus

Command bus for ruby

Installation

Add this line to your application's Gemfile:

gem 'koine-command_bus'

And then execute:

$ bundle

Or install it yourself as:

$ gem install koine-command_bus

Usage

The command

class App::Command::ClearDirectory
  attr_reader :dir

  def initialize(dir)
    @dir = dir
  end
end

Handler

class App::CommandHandler::ClearDirectory
  def handle(command)
    system("rm -rf #{command.dir}/*")
  end
end

And if you want to run:

command = App::Command::ClearDirectory.new('/tmp')
handler = App::CommandHandler::ClearDirectory.new
handler.handle(command)

But if you want a sigle object to be responsible to route to the correct handler you can use the command bus

The command bus

You can create a handler, as follows:

class MyCommandHandlerResolver
  def resolve(command)
    handler_class(command).new
  end

  def handler_class(command)
    klass = command.class.to_s.gsub('Command', 'CommandHandler')
    Object.const_get(klass)
  end
end

Append the resolver to the command bus

command_bus = Koine::CommandBus::CommandBus.new
command_bus.resolvers << MyCommandHandlerResolver.new

command = App::Command::ClearDirectory.new('/tmp')
command_bus.handle(command) # dir cleared!

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake test 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/mjacobus/koine-command_bus. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

The gem is available as open source under the terms of the MIT License.

mjacobus/koine-command-bus