LRFalk01 / riker

Riker

High-Performance, Dependency-Free Command Pattern For Ruby

Simple Usage

In your gemfile:

gem 'riker', '0.1.0.pre6'

In your code:

class SimpleGreeting
  extend Riker

  param :first_name
  param :last_name, required: false
  param :punctuation, default: '.'

  execute do
    if first_name == 'Voldemort'
      errors.add(:first_name, 'He who shall not be named!')
      return
    end

    return "Hello #{first_name}#{punctuation}" if last_name.nil?

    "Hello #{first_name} #{last_name}#{punctuation}"
  end
end

In use:

SimpleGreeting.run!(first_name: 'Will')
# => "Hello Will."

SimpleGreeting.run!(first_name: 'Will', last_name: 'Riker')
# => "Hello Will Riker."

SimpleGreeting.run!(first_name: 'Will', last_name: 'Riker', punctuation: '!')
# => "Hello Will Riker!"

SimpleGreeting.run!(first_name: 'Voldemort')
# => Riker::Outcome::ExecutionError => e
# =>   e.errors.messages == ['He who shall not be named!']

outcome = SimpleGreeting.run(first_name: 'Will')
outcome.valid?
# => true
outcome.result
# => "Hello Will."

outcome = SimpleGreeting.run(first_name: 'Voldemort')
outcome.invalid?
# => true
outcome.result
# => nil
outcome.errors.messages
# => ['He who shall not be named!']

Default Procs

In your code:

class CaptainsLog
  extend Riker

  param :stardate, default: -> { Time.now.to_f }
  param :message

  execute do
    "Captain's Log; Stardate: #{stardate}\n\n#{message}"
  end
end

In use:

CaptainsLog.run!(message: "The Borg are attacking!")
# => "Captain's Log; Stardate: 1664393978.915553\n\nThe Borg are attacking!"

CaptainsLog.run(message: "We've traveled back in time!", stardate: 42.1337)
# => "Captain's Log; Stardate: 42.1337\n\nWe've traveled back in time!"

Measurement Code

Sometimes you'll want to do some logic around your commands to record their performance, number of calls, etc. Rike allows for this with around. The result of your measurement code in no way effects the result from the command.

module SensorArray
  class << self
    # the class and args of the command are provided
    def deep_scan(klass, args)
      # anything before code runs

      # code runs here
      yield

      # anything after you want
    end
  end
end

class CheckWarpDrive
  extend Riker

  param :stardate
  param :engineer

  around &SensorArray.method(:deep_scan)

  execute do
    "WarpDrive checked by #{engineer} on #{stardate}"
  end
end