Module: FlexaLib::ActiveRecord::Lookup

Defined in:
lib/flexa_lib/model_extensions.rb

Overview

fim do modulo PesquisaWrapper

Instance Method Summary collapse

Instance Method Details

#delegate_lookup(*methods) ⇒ Object 



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# File 'lib/flexa_lib/model_extensions.rb', line 36

def delegate_lookup(*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

  to = to.to_s
  prefix, allow_nil = options.values_at(:prefix, :allow_nil)

  prefix = true if prefix.nil?
  allow_nil = true if allow_nil.nil?


  if prefix == true && to =~ /^[^a-z_]/
    raise ArgumentError, "Can only automatically set the delegation prefix when delegating to a method."
  end

  method_prefix =
    if prefix
      "#{prefix == true ? to : prefix}_"
    else
      ''
    end

  file, line = caller.first.split(':', 2)
  line = line.to_i

  methods.each do |method|
    method = method.to_s

    # Attribute writer methods only accept one argument. Makes sure []=
    # methods still accept two arguments.
    definition = (method =~ /[^\]]=$/) ? "arg" : "*args, &block"

    if allow_nil
      module_eval(<<-EOS, file, line - 2)
        def #{method_prefix}#{method}(#{definition})        # def customer_name(*args, &block)
          if #{to} || #{to}.respond_to?(:#{method})         #   if client || client.respond_to?(:name)
            #{to}.#{method}(#{definition})                  #     client.name(*args, &block)
          end                                               #   end
        end                                                 # end
      EOS
    else
      exception = %(raise "#{self}##{method_prefix}#{method} delegated to #{to}.#{method}, but #{to} is nil: \#{self.inspect}")

      module_eval(<<-EOS, file, line - 1)
        def #{method_prefix}#{method}(#{definition})        # def customer_name(*args, &block)
          #{to}.#{method}(#{definition})                    #   client.name(*args, &block)
        rescue NoMethodError                                # rescue NoMethodError
          if #{to}.nil?                                     #   if client.nil?
            #{exception}                                    #     # add helpful message to the exception
          else                                              #   else
            raise                                           #     raise
          end                                               #   end
        end                                                 # end
      EOS
    end

    #cria funcao com valor false
      module_eval(<<-EOS, file, line - 2)
        def #{method_prefix}#{method}=(val)                 # def customer_name=(val)
          false                                             #   false
        end                                                 # end
      EOS
    #cria funcao com valor false
  end
end