Module: Casting::SuperDelegate

Defined in:
lib/casting/super_delegate.rb

Instance Method Summary collapse

Instance Method Details

#calling_location(call_stack) ⇒ Object 



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# File 'lib/casting/super_delegate.rb', line 52

def calling_location(call_stack)
  call_stack.reject{|line| 
    line.to_s.match? Regexp.union(casting_library_matcher, gem_home_matcher, debugging_matcher)
  }.first
end

#casting_library_matcher ⇒ Object 



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# File 'lib/casting/super_delegate.rb', line 62

def casting_library_matcher
  Regexp.new(Dir.pwd.to_s + '/lib')
end

#debugging_matcher ⇒ Object 



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# File 'lib/casting/super_delegate.rb', line 70

def debugging_matcher
  Regexp.new('internal:trace_point')
end

#gem_home_matcher ⇒ Object 



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# File 'lib/casting/super_delegate.rb', line 66

def gem_home_matcher
  Regexp.new(ENV['GEM_HOME'])
end

#method_delegate_skipping(meth, skipped) ⇒ Object 



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# File 'lib/casting/super_delegate.rb', line 45

def method_delegate_skipping(meth, skipped)
  skipped_index = __delegates__.index(skipped)
  __delegates__[(skipped_index + 1)..__delegates__.length].find{|attendant|
    attendant_methods(attendant).include?(meth)
  }
end

#name_of_calling_method(call_stack) ⇒ Object 



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# File 'lib/casting/super_delegate.rb', line 58

def name_of_calling_method(call_stack)
  calling_location(call_stack).label.to_sym
end

#super_delegate(mod = :none, *args, **kwargs, &block) ⇒ Object

Call the method of the same name defined in the next delegate stored in your object

Because Casting creates an alternative method lookup path using a collection of delegates, you may use ‘super_delegate` to work like `super`.

If you use this feature, be sure that you have created a delegate collection which does have the method you need or you’ll see a NoMethodError.

Example:

module Greeter

def greet
  "Hello"
end

end

module FormalGreeter

include Casting::Super

def greet
  "#{super_delegate}, how do you do?"
end

end

some_object.cast_as(Greeter, FormalGreeter) some_object.greet #=> ‘Hello, how do you do?’



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# File 'lib/casting/super_delegate.rb', line 31

def super_delegate(mod = :none, *args, **kwargs, &block)
  method_name = name_of_calling_method(caller_locations)
  owner = (mod unless mod == :none) || method_delegate(method_name)

  super_delegate_method = unbound_method_from_next_delegate(method_name, owner)
  super_delegate_method.bind(self).call(*args, **kwargs, &block)
rescue NameError
  raise NoMethodError.new("super_delegate: no delegate method `#{method_name}' for #{self.inspect} from #{owner}")
end

#unbound_method_from_next_delegate(method_name, *skipped) ⇒ Object 



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# File 'lib/casting/super_delegate.rb', line 41

def unbound_method_from_next_delegate(method_name, *skipped)
  method_delegate_skipping(method_name, *skipped).instance_method(method_name)
end