Module: ForwardableX

Included in:
Object
Defined in:
lib/forwardablex.rb,
lib/forwardablex/version.rb

Overview

ForwardableX is a module for providing extra Forwardable functions. Benefits to use this library are the following:

  • you can use easy keyword “forward”, instead of “def_instance_delegator” or “def_delegator”

  • you can specify message receiver as instance variable name, Proc object or plain object

  • no need to declare “extend Forwardable”

  • forwardable.rb compatible API

Examples:

Forward to Instance Variable

Receiver = Struct(:m)
class Forwarder
  forward :@receiver, :m
  def initialize
    @recevier = Receiver.new("forwarded")
  end
end
Forwarder.new.m #=> "forwarded"

Forward to Proc Receiver

class Forwarder
  forward lambda{Struct(:m).new("forwarded")}, :m
end
Forwarder.new.m #=> "forwarded"

Forward to Instance

Receiver = Struct(:m)
class Forwarder
  forward Receiver.new("forwarded"), :m
end
Forwarder.new.m #=> "forwarded"

Class Method Accessor

Receiver = Struct(:name)
class Forwarder
  class << self
    def m
      "forwarded"
    end
  end
  forward :class, :m
end
Forwarder.new.m #=> "forwarded"

Constant Summary collapse

VERSION =

version of ForwardableX

"0.1.3"

Instance Method Summary collapse

Instance Method Details

#delegate(hash) ⇒ void

This method returns an undefined value.

Same as Forwardable#delegate, but you can specify receivers as instance variable name, Proc object, and plain object.

Parameters:

  • hash (Hash) —

    the hash table contains keys as methods and values as recevier



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# File 'lib/forwardablex.rb', line 104

def delegate(hash)
  hash.each do |methods, receiver|
    forward!(receiver, *methods)
  end
end

#forward(receiver, method, name = method) ⇒ void Also known as: def_instance_delegator, def_singleton_delegator, def_delegator

This method returns an undefined value.

Define a method that forwards the message to the receiver. You can specify receiver as instance variable name, Proc object, and plain object.

Parameters:

  • receiver (Symbol, String, Proc, or Object) —

    message receiver

  • method (Symbol) —

    method name that we forward to

  • name (Symbol) (defaults to: method) —

    method name that we forward from



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# File 'lib/forwardablex.rb', line 55

def forward(receiver, method, name=method)
  context = self.kind_of?(Module) ? self : self.singleton_class
  context.instance_eval do
    case receiver
    when :class
      define_method(name) do |*args, &b|
        self.class.__send__(method, *args, &b)
      end
    when Symbol, String
      define_method(name) do |*args, &b|
        instance_variable_get(receiver).__send__(method, *args, &b)
      end
    when Proc
      define_method(name) do |*args, &b|
        instance_eval(&receiver).__send__(method, *args, &b)
      end
    else
      define_method(name) do |*args, &b|
        receiver.__send__(method, *args, &b)
      end
    end
  end
end

#forward!(receiver, *methods) ⇒ void Also known as: def_instance_delegators, def_singleton_delegators, def_delegators

This method returns an undefined value.

Define each method that calls the receiver’s method.

Parameters:

  • receiver (Symbol, String, Proc, or Object) —

    message receiver

  • methods (Array<Symbol>) —

    method names that we forward to



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# File 'lib/forwardablex.rb', line 89

def forward!(receiver, *methods)
  methods.delete("__send__")
  methods.delete("__id__")
  methods.each {|method| forward(receiver, method)}
end

#forward_as_key(receiver, key, name = key) ⇒ void

This method returns an undefined value.

Define a method that forwards the key to the receiver. You can specify receiver as instance variable name, Proc object, and plain object.

Parameters:

  • receiver (Symbol, String, Proc, or Object) —

    message receiver that have method #[]

  • key (Symbol) —

    key that we forward to the receiver

  • name (Symbol) (defaults to: key) —

    method name that we forward from



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# File 'lib/forwardablex.rb', line 120

def forward_as_key(receiver, key, name=key)
  context = self.kind_of?(Module) ? self : self.singleton_class
  context.instance_eval do
    case receiver
    when :class
      define_method(name) do |*args, &b|
        self.class.__send__(:[], key, *args, &b)
      end
    when Symbol, String
      define_method(name) do |*args, &b|
        instance_variable_get(receiver).__send__(:[], key, *args, &b)
      end
    when Proc
      define_method(name) do |*args, &b|
        instance_eval(&receiver).__send__(:[], key, *args, &b)
      end
    else
      define_method(name) do |*args, &b|
        receiver.__send__(:[], key, *args, &b)
      end
    end
  end
end

#forward_as_key!(receiver, *keys) ⇒ void

This method returns an undefined value.

Define each method that forwards to the receiver as key.

Parameters:

  • receiver (Symbol, String, Proc, or Object) —

    message receiver that have method #[]

  • key (Array<Symbol>) —

    key that we forward to the receiver



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# File 'lib/forwardablex.rb', line 151

def forward_as_key!(receiver, *keys)
  keys.each {|key| forward_as_key(receiver, key)}
end