Rails - Oct 2009 - Self and Protected Methods question/confusion

Hi,

I''m still trying to learn the in''s and out''s of Ruby
and Rails.  I''ve
been testing my code a million different ways and have read a number of
books and web sites, but something is still not clicking for me.  I want
to be able to call the protected methods and I have read both David
Black''s and Prag Programmers books about how self can be tricky.  But I
still don''t know how to make it work.  I want to call method_a and have
it then process both protected methods.

Is it possible to call my method_a directly (as shown in my script code)
without having to do this:

k = Klass.new
k.method_a

------------------------

I''ve got this right now.

This is called from a script.
k = Klass.method_a(:variable = v)

My model:
class Klass

  def self.method_a(params = {})
    a = Model.find(:first, :conditions => ["variable = ?",
variable])
    a.do_something
    a.do_more
    return a
  end

  protected

  def do_something
    puts "inside do_something"
  end

  def do_more
    puts "inside do_more"
  end

end


Thanks for helping a Ruby Newbie.
-- 
Posted via http://www.ruby-forum.com/.

On Mon, Oct 26, 2009 at 5:26 PM, Cs Webgrl
<rails-mailing-list-ARtvInVfO7ksV2N9l4h3zg@public.gmane.org>
wrote:
> I''m still trying to learn the in''s and out''s of
Ruby and Rails.  I''ve
> been testing my code a million different ways and have read a number of
> books and web sites, but something is still not clicking for me.  I want
> to be able to call the protected methods
Ruby''s object system is a message passing system.  If you have an
object foo, and you do:

foo.some_method

foo doesn''t perform a method call on itself.  foo just looks for
somewhere to send the "some_method" message, somewhere that returns
true for respond_to?

foo.respond_to?(:some_message)

In knowing how this works, you can send the message yourself, ignoring
the private or protected nature of the receiver along the way.

Here''s an example:

#!/usr/bin/env ruby

class Foo
  private
  def hidden
    puts "I am hidden"
  end
end

f = Foo.new

begin
  f.hidden
rescue
  puts "Can''t run hidden: #{ $! }"
end

f.send( :hidden )
> ./private.rb
Can''t run hidden: private method `hidden'' called for
#<Foo:0xb7c2f92c>
I am hidden


-- 
Greg Donald
http://destiney.com/

Greg Donald wrote:
> 
> Here''s an example:
> 
> #!/usr/bin/env ruby
> 
> class Foo
>   private
>   def hidden
>     puts "I am hidden"
>   end
> end
> 
> f = Foo.new
> 
> begin
>   f.hidden
> rescue
>   puts "Can''t run hidden: #{ $! }"
> end
> 
> f.send( :hidden )
> 
>> ./private.rb
> 
> Can''t run hidden: private method `hidden'' called for
#<Foo:0xb7c2f92c>
> I am hidden
> 


Thank you for your example.  I was able to test my code and call my 
methods using object.send (:method)

My follow-up question to this is now, is this the best way to handle the 
protected methods using the code sample that I have above?  Or do I have 
a design flaw in the code?  Should I explicitly create and call 
object.New and  the method instead of creating the object like I am 
doing?

Thanks for your help.
-- 
Posted via http://www.ruby-forum.com/.