Class: Delegator

Inherits:

Object

• Object
• Delegator

show all

Defined in:

lib/delegate.rb

Overview

Class Method Summary (collapse)

• + (Object) delegating_block(mid)

  :stopdoc:.

Instance Method Summary (collapse)

• - (Object) ==(obj)

  Returns true if two objects are considered same.

• - (Object) __getobj__

  This method must be overridden by subclasses and should return the object method calls are being delegated to.

• - (Object) __setobj__(obj)

  This method must be overridden by subclasses and change the object delegate to obj.

• - (Object) clone

  Clone support for the object returned by __getobj__.

• - (Object) dup

  Duplication support for the object returned by __getobj__.

• - (Delegator) initialize(obj) constructor

  Pass in the obj to delegate method calls to.

• - (Object) marshal_dump

  Serialization support for the object returned by __getobj__.

• - (Object) marshal_load(obj)

  Reinitializes delegation from a serialized object.

• - (Object) method_missing(m, *args, &block)

  Handles the magic of delegation through __getobj__.

• - (Boolean) respond_to?(m, include_private = false)

  Checks for a method provided by this the delegate object by fowarding the call through __getobj__.

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# File 'lib/delegate.rb', line 126

def initialize(obj)
  __setobj__(obj)
end

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# File 'lib/delegate.rb', line 131

def method_missing(m, *args, &block)
  begin
    target = self.__getobj__
    unless target.respond_to?(m)
      super(m, *args, &block)
    else
      target.__send__(m, *args, &block)
    end
  rescue Exception
    $@.delete_if{|s| %r"\A#{__FILE__}:\d+:in `method_missing'\z"o =~ s}
    ::Kernel::raise
  end
end

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# File 'lib/delegate.rb', line 234

def Delegator.delegating_block(mid)
  lambda do |*args, &block|
    begin
      __getobj__.__send__(mid, *args, &block)
    rescue
      re = /\A#{Regexp.quote(__FILE__)}:#{__LINE__-2}:/o
      $!.backtrace.delete_if {|t| re =~ t}
      raise
    end
  end
end

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# File 'lib/delegate.rb', line 157

def ==(obj)
  return true if obj.equal?(self)
  self.__getobj__ == obj
end

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# File 'lib/delegate.rb', line 166

def __getobj__
  raise NotImplementedError, "need to define `__getobj__'"
end

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# File 'lib/delegate.rb', line 174

def __setobj__(obj)
  raise NotImplementedError, "need to define `__setobj__'"
end

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# File 'lib/delegate.rb', line 188

def clone
  new = super
  new.__setobj__(__getobj__.clone)
  new
end

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# File 'lib/delegate.rb', line 194

def dup
  new = super
  new.__setobj__(__getobj__.dup)
  new
end

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# File 'lib/delegate.rb', line 179

def marshal_dump
  __getobj__
end

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# File 'lib/delegate.rb', line 183

def marshal_load(obj)
  __setobj__(obj)
end

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# File 'lib/delegate.rb', line 149

def respond_to?(m, include_private = false)
  return true if super
  return self.__getobj__.respond_to?(m, include_private)
end