DecisionMaker

DecisionMaker is a library which behaves as a decision table and it makes complicated dispatching logic much simpler. See following usages for details.

Installation

Add this line to your application's Gemfile:

gem 'decision_maker'

And then execute:

$ bundle

Or install it yourself as:

$ gem install decision_maker

Usage

Simple dynamic definition style.

require 'decision_maker'

ticket_price = DecisionMaker.generate do
  rule(
    child:   { condition:  0..9,   action: 600 },
    student: { condition: 10..16,  action: 1200 },
    adult:   { condition: ->(age) { age > 16 }, action: 2000 },
  )
end

ticket_price.call(20) #=> 2000

Class definition style.

require 'decision_maker'

TicketPrice = DecisionMaker.define do
  rule(
    child:   { condition:  0..9,   action: 600 },
    student: { condition: 10..16,  action: 1200 },
    adult:   { condition: ->(age) { age > 16 }, action: 2000 },
  )
end

ticket_price = TicketPrice.new
ticket_price.call(20) #=> 2000

Dynamic definition style with some name customizations.

require 'decision_maker'

ticket_price = DecisionMaker.generate do
  name           :calculate
  condition_name :age
  action_name    :price

  rule(
    child:   { age:  0..9,   price: 600 },
    student: { age: 10..16,  price: 1200 },
    adult:   { age: ->(age) { age > 16 }, price: 2000 },
  )
end

ticket_price.calculate(20) #=> 2000

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/sunaot/decision_maker.

License

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