Class: Module

Inherits:
Object
  • Object
show all
Defined in:
lib/active_storage/patches/delegation.rb

Defined Under Namespace

Classes: DelegationError

Constant Summary collapse

RUBY_RESERVED_KEYWORDS = 
%w(__ENCODING__ __LINE__ __FILE__ alias and BEGIN begin break
case class def defined? do else elsif END end ensure false for if in module next nil
not or redo rescue retry return self super then true undef unless until when while yield)
DELEGATION_RESERVED_KEYWORDS = 
%w(_ arg args block)
DELEGATION_RESERVED_METHOD_NAMES = 
Set.new(
  RUBY_RESERVED_KEYWORDS + DELEGATION_RESERVED_KEYWORDS
).freeze

Instance Method Summary collapse

Instance Method Details

#delegate_missing_to(target, allow_nil: nil) ⇒ Object 



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# File 'lib/active_storage/patches/delegation.rb', line 65

def delegate_missing_to(target, allow_nil: nil)
  target = target.to_s
  target = "self.#{target}" if DELEGATION_RESERVED_METHOD_NAMES.include?(target)

  module_eval <<-RUBY, __FILE__, __LINE__ + 1
    def respond_to_missing?(name, include_private = false)
      # It may look like an oversight, but we deliberately do not pass
      # +include_private+, because they do not get delegated.
  
      return false if name == :marshal_dump || name == :_dump
      #{target}.respond_to?(name) || super
    end
  
    def method_missing(method, *args, &block)
      if #{target}.respond_to?(method)
        #{target}.public_send(method, *args, &block)
      else
        begin
          super
        rescue NoMethodError
          if #{target}.nil?
            if #{allow_nil == true}
              nil
            else
              raise DelegationError, "\#{method} delegated to #{target}, but #{target} is nil"
            end
          else
            raise
          end
        end
      end
    end
  RUBY
end