On Friday, 10 October 2014 09:08:29 UTC-4, rusik wrote: > > Hello all. > > In this example, as i understand that *included* block is running when > Exclaimable module is included in Person and *after* a Person class > methods are 'initialized' >
No. See below for additional information, but if `include Exclaimable` is the first thing in a class definition, only methods defined on the declaring class's superclass (Object, in the case of Person) will be available. > > >> require 'active_support/concern' >> > > >> module Exclaimable >> extend ActiveSupport::Concern >> included do >> self.new.hello >> end >> end >> > > >> class Person >> include Exclaimable >> def hello >> puts 'person hello' >> end >> end > > > Output: Exception: NoMethodError: undefined method `hello' for > #<Person:0x00000103cbdcd0> > > But i see that, Person class doesn't have hello method, why ? Please, > help ! > The stuff between `class Person` and `end` is just code. The `hello` method isn't available yet because it hasn't been DEFINED yet when `include Exclaimable` executes. > So, i can't understand - what diifference between > > >> included do >> self.new.hello >> end > > > and class method: > > >> self.included(base) >> base.new.hello >> end > > > Both code get same error ( see above ) > `self.included` is Ruby's built-in hook. ( http://www.ruby-doc.org/core-2.1.3/Module.html#method-i-included ) It gets called when the module that declares it is included in another module or class. `ActiveSupport::Concern` adds the `included do` idiom, to make situations where one module depends on another more straightforward. See the last section of the docs for more: http://api.rubyonrails.org/classes/ActiveSupport/Concern.html --Matt Jones -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To unsubscribe from this group and stop receiving emails from it, send an email to rubyonrails-talk+unsubscr...@googlegroups.com. To post to this group, send email to rubyonrails-talk@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/rubyonrails-talk/d54def3c-678d-4188-b0e5-63fbec468f8d%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
