diff options
Diffstat (limited to 'activesupport/lib/active_support/core_ext/module/delegation.rb')
| -rw-r--r-- | activesupport/lib/active_support/core_ext/module/delegation.rb | 40 |
1 files changed, 22 insertions, 18 deletions
diff --git a/activesupport/lib/active_support/core_ext/module/delegation.rb b/activesupport/lib/active_support/core_ext/module/delegation.rb index af92b869fd..fbef27c76a 100644 --- a/activesupport/lib/active_support/core_ext/module/delegation.rb +++ b/activesupport/lib/active_support/core_ext/module/delegation.rb @@ -1,5 +1,5 @@ class Module - # Provides a delegate class method to easily expose contained objects' methods + # Provides a delegate class method to easily expose contained objects' public methods # as your own. Pass one or more methods (specified as symbols or strings) # and the name of the target object via the <tt>:to</tt> option (also a symbol # or string). At least one method and the <tt>:to</tt> option are required. @@ -8,11 +8,11 @@ class Module # # class Greeter < ActiveRecord::Base # def hello - # "hello" + # 'hello' # end # # def goodbye - # "goodbye" + # 'goodbye' # end # end # @@ -62,7 +62,7 @@ class Module # delegate :name, :address, :to => :client, :prefix => true # end # - # john_doe = Person.new("John Doe", "Vimmersvej 13") + # john_doe = Person.new('John Doe', 'Vimmersvej 13') # invoice = Invoice.new(john_doe) # invoice.client_name # => "John Doe" # invoice.client_address # => "Vimmersvej 13" @@ -74,8 +74,8 @@ class Module # end # # invoice = Invoice.new(john_doe) - # invoice.customer_name # => "John Doe" - # invoice.customer_address # => "Vimmersvej 13" + # invoice.customer_name # => 'John Doe' + # invoice.customer_address # => 'Vimmersvej 13' # # If the delegate object is +nil+ an exception is raised, and that happens # no matter whether +nil+ responds to the delegated method. You can get a @@ -104,17 +104,17 @@ class Module 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)." + 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) if prefix == true && to =~ /^[^a-z_]/ - raise ArgumentError, "Can only automatically set the delegation prefix when delegating to a method." + raise ArgumentError, 'Can only automatically set the delegation prefix when delegating to a method.' end - method_prefix = + method_prefix = \ if prefix "#{prefix == true ? to : prefix}_" else @@ -124,23 +124,27 @@ class Module file, line = caller.first.split(':', 2) line = line.to_i - if allow_nil - methods.each do |method| + 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}(*args, &block) # def customer_name(*args, &block) + def #{method_prefix}#{method}(#{definition}) # def customer_name(*args, &block) if #{to} || #{to}.respond_to?(:#{method}) # if client || client.respond_to?(:name) - #{to}.__send__(:#{method}, *args, &block) # client.__send__(:name, *args, &block) + #{to}.#{method}(#{definition}) # client.name(*args, &block) end # end end # end EOS - end - else - methods.each do |method| + 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}(*args, &block) # def customer_name(*args, &block) - #{to}.__send__(:#{method}, *args, &block) # client.__send__(:name, *args, &block) + 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 |