Module: FerryCore::ModuleExtensions

Defined in:
lib/locomotive/core_extensions/module.rb

Overview

extensions to enhance an object with some attributes and derive simple methods

Instance Method Summary collapse

Instance Method Details

#attributes(*attrs) ⇒ Object

extend the instance with some new attributes



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# File 'lib/locomotive/core_extensions/module.rb', line 26

def attributes(*attrs)
  @attributes = attrs
  attr_reader(*attrs)
end

#delegate(*methods) ⇒ Object

stolen from active_support reimplement it by time since it use deprecated string metaprogramming



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# File 'lib/locomotive/core_extensions/module.rb', line 37

def delegate(*methods)
  options = methods.pop
  unless options.is_a?(Hash) && to = options[:to]
    raise ArgumentError, "Delegation needs a target. Supply an options hash with a :to key as the last argument (e.g. delegate :hello, :to => :greeter)."
  end
  
  if options[:prefix] == true && options[:to].to_s =~ /^[^a-z_]/
    raise ArgumentError, "Can only automatically set the delegation prefix when delegating to a method."
  end
  
  prefix = options[:prefix] && "#{options[:prefix] == true ? to : options[:prefix]}_"
  
  file, line = caller.first.split(':', 2)
  line = line.to_i
  
  methods.each do |method|
    on_nil =
      if options[:allow_nil]
        'return'
      else
        %(raise "#{self}##{prefix}#{method} delegated to #{to}.#{method}, but #{to} is nil: \#{self.inspect}")
      end
  
    module_eval(<<-EOS, file, line)
      def #{prefix}#{method}(*args, &block)               # def customer_name(*args, &block)
        #{to}.__send__(#{method.inspect}, *args, &block)  #   client.__send__(:name, *args, &block)
      rescue NoMethodError                                # rescue NoMethodError
        if #{to}.nil?                                     #   if client.nil?
          #{on_nil}
        else                                              #   else
          raise                                           #     raise
        end                                               #   end
      end                                                 # end
    EOS
  end
end

#deriving(*methods) ⇒ Object 



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# File 'lib/locomotive/core_extensions/module.rb', line 31

def deriving(*methods)
  methods.each(&method(:derive))
end