Rails - Jul 2006 - Don''t understand :: in ActionController::Base

Maybe this should apply to Ruby forums directly, but I''ll try here.

I understand the concept of classes and subclasses thanks to the 
excellent "Programming Ruby - The Pragmatic Programmer''s
Guide".
However, I don''t understand what :: signify in terms of inheritance, 
parent and child in e.g.

ActionController::Base

-- 
Posted via http://www.ruby-forum.com/.

P?l Bergstr?m wrote:
> Maybe this should apply to Ruby forums directly, but I''ll try
here.
> 
> I understand the concept of classes and subclasses thanks to the 
> excellent "Programming Ruby - The Pragmatic Programmer''s
Guide".
> However, I don''t understand what :: signify in terms of
inheritance,
> parent and child in e.g.
> 
> ActionController::Base
> 
You''re correct, this is definitely not a question for rails-talk. Take
a
look at ruby-talk instead. (Btw, if you actually have read the pickaxe, 
may I refer you to chapter 9, starting at page 117?)

-- 
  Ola Bini (http://ola-bini.blogspot.com)
  JvYAML, RbYAML, JRuby and Jatha contributor
  System Developer, Karolinska Institutet (http://www.ki.se)
  OLogix Consulting (http://www.ologix.com)

  "Yields falsehood when quined" yields falsehood when quined.

Hi --

On Fri, 14 Jul 2006, Pål Bergström wrote:
> Maybe this should apply to Ruby forums directly, but I''ll try
here.
>
> I understand the concept of classes and subclasses thanks to the
> excellent "Programming Ruby - The Pragmatic Programmer''s
Guide".
> However, I don''t understand what :: signify in terms of
inheritance,
> parent and child in e.g.
>
> ActionController::Base
:: navigates through nested classes and modules.  So what you''ve got
in the Rails source code is basically:

   module ActionController
     class Base
     end
   end

(plus the actual code that does anything :-)  So now there''s a class
called ActionController::Base, from which your controller classes can
inherit.


David

-- 
http://www.rubypowerandlight.com => Ruby/Rails training & consultancy
http://www.manning.com/black     => RUBY FOR RAILS (reviewed on
                                     Slashdot, 7/12/2006!)
http://dablog.rubypal.com        => D[avid ]A[. ]B[lack''s][ Web]log
dblack@wobblini.net              => me

Ola Bini wrote:
> P?l Bergstr?m wrote:
>> Maybe this should apply to Ruby forums directly, but I''ll try
here.
>> 
>> I understand the concept of classes and subclasses thanks to the 
>> excellent "Programming Ruby - The Pragmatic Programmer''s
Guide".
>> However, I don''t understand what :: signify in terms of
inheritance,
>> parent and child in e.g.
>> 
>> ActionController::Base
>> 
> 
> You''re correct, this is definitely not a question for rails-talk.
Take a
> look at ruby-talk instead. (Btw, if you actually have read the pickaxe,
> may I refer you to chapter 9, starting at page 117?)
Definitely was harsh. I thought ActionController::Base was part of RoR 
:-)

I read it on the web with no chapters, so if you could be more specific 
I would be very thankful.

-- 
Posted via http://www.ruby-forum.com/.

Put simply.... you have to understand Ruby before you really understand
Rails. David Black''s excellent book Ruby for Rails is a definite read
if you
are having trouble with the concepts.

Don''t take this personally, but there have been a lot of questions
posted to
this list lately that really have more to do with the fundamentals of the
Ruby language than with the way Rails works.  Sometimes the line is blurry
and it''s hard to tell.

-bph.


On 7/14/06, P?l Bergstr?m <pal@palbergstrom.com>
wrote:
>
> Ola Bini wrote:
> > P?l Bergstr?m wrote:
> >> Maybe this should apply to Ruby forums directly, but I''ll
try here.
> >>
> >> I understand the concept of classes and subclasses thanks to the
> >> excellent "Programming Ruby - The Pragmatic
Programmer''s Guide".
> >> However, I don''t understand what :: signify in terms of
inheritance,
> >> parent and child in e.g.
> >>
> >> ActionController::Base
> >>
> >
> > You''re correct, this is definitely not a question for
rails-talk. Take a
> > look at ruby-talk instead. (Btw, if you actually have read the
pickaxe,
> > may I refer you to chapter 9, starting at page 117?)
>
> Definitely was harsh. I thought ActionController::Base was part of RoR
> :-)
>
> I read it on the web with no chapters, so if you could be more specific
> I would be very thankful.
>
> --
> Posted via http://www.ruby-forum.com/.
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
>
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Brian Hogan wrote:
> Put simply.... you have to understand Ruby before you really understand
> Rails. David Black''s excellent book Ruby for Rails is a definite
read if
> you
> are having trouble with the concepts.
> 
> Don''t take this personally, but there have been a lot of questions
> posted to
> this list lately that really have more to do with the fundamentals of 
> the
> Ruby language than with the way Rails works.  Sometimes the line is 
> blurry
> and it''s hard to tell.
> 
> -bph.
I understand. Don''t worry Brian. I don''t take it personally.
Not the
first time I use a forum and give answers myself. We''re all newbies in 
the beginning, and it sometimes takes some patience with the level 
people are on. But I always try to give my best to those who ask, no 
matter what, and not give non-answers. :-)

I can''t help Ruby and RoR is so closely related and the documentation
is
what it is. Maybe this is why you get a lot of questions about Ruby here 
in RoR? The documentation has some things to wish for. Not Ruby itself. 
That has been the easy part. But I haven''t read all of it, as I want to
get started as soon as possible by building in RoR and learn as I go 
along. That is how I''ve learned other languages. For what I know a 
question in the Ruby forum could give the answer that :: is a RoR thing 
and should be answered here. Right?

So I''ll pop over to the Ruby forum and ask there. Maybe I''ll
see you
there? :-)

-- 
Posted via http://www.ruby-forum.com/.

On Friday 14 July 2006 13:11, P?l Bergstr?m wrote:
> I can''t help Ruby and RoR is so closely related and the
documentation
> is what it is. Maybe this is why you get a lot of questions about Ruby
> here in RoR? The documentation has some things to wish for. Not Ruby
> itself. That has been the easy part. 
But your problem *is* with ruby itself.
> For what I know a
> question in the Ruby forum could give the answer that :: is a RoR thing
> and should be answered here. Right?
It''s pretty rare (even in the ruby world) that a framework adds its own
custom operator(s) to a language :)
Re-read the relevant parts of the pickaxe -- good keywords to look for are 
e.g. "namespace", "operator", "modules"
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