Class: SimpleState::Builder::StateBuilder

Inherits:
Object
  • Object
show all
Defined in:
lib/simple_state/builder.rb

Overview

Responsible for building events for a given state.

Instance Method Summary collapse

Constructor Details

#initialize(klass, mod, state) ⇒ StateBuilder

Returns a new instance of StateBuilder.



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# File 'lib/simple_state/builder.rb', line 77

def initialize(klass, mod, state)
  @klass, @module, @state = klass, mod, state
end

Instance Method Details

#build(&blk) ⇒ Object

Specialises a state by defining events.

Parameters:

  • &blk (Block) —

    An block for defining transitions for the state.



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# File 'lib/simple_state/builder.rb', line 87

def build(&blk)
  instance_eval(&blk)
end

#event(event, opts = {}) ⇒ Object

Defines an event and transition.

Parameters:

  • event_name (Symbol) —

    A name for this event.

  • opts (Hash) (defaults to: {}) —

    An options hash for customising the event.



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# File 'lib/simple_state/builder.rb', line 97

def event(event, opts = {})
  unless opts[:transitions_to].kind_of?(Symbol)
    raise ArgumentError, 'You must declare a :transitions_to state ' \
                         'when defining events'
  end

  # Keep track of valid transitions for this state.
  @klass.states[@state].push([event, opts[:transitions_to]])

  unless @module.method_defined?(:"#{event}!")
    # Example:
    #
    # def process!
    #   if self.class._valid_transition?(self.state, :process)
    #     self.state =
    #       self.class._determine_new_state(self.state, :process)
    #   else
    #     false
    #   end
    # end
    @module.class_eval <<-RUBY, __FILE__, __LINE__ + 1
      def #{event}!
        if self.class._valid_transition?(self.state, :#{event})
          self.state =
            self.class._determine_new_state(self.state, :#{event})
        else
          false
        end
      end
    RUBY
  end
end