Properly checking method definition and wether to alias if undefined?

[Kain Nobel]

Good day everybody!

Although I'm somewhat familiar with 'self.method_defined?()', or in other words I've at least seen it used, I was curious whats the proper way to use it, or what are the different ways it can be used? For instance, I always see people checking the alias name of a method instead of the origional name of the method, why is that? Are they checking if an alias from a previous script exists? I've never seen another scripter just checking for the origional method, I always see just an alias name being checked so I'm unsure.

Simply, what I'm trying to do is prevent overwritting SDK::Scene_Base methods in my scenes where, the method isn't by default defined, and its unclear if it would need to be aliased or not.

So, if I was to create 'main_window' for Scene_Gameover (since it, by default, doesn't use any windows it isn't created), how would I be sure that I'm not overwritting some other code somewhere previous to that call? Can I freely alias a superclass method, such as when Scene_Gameover inherits from the SDK::Scene_Base?

How do I work that situation, am I supposed to do something like...?

class Scene_Gameover < SDK::Scene_Base
  alias_method :exampl_scn_gmover_main_window, :main_window
  def main_window
    if self.method_defined?(:main_window)
      exampl_scn_gmover_main_window
    end
    # ...New code...
  end
end

I'm just asking because, although I've seen it used, I don't know exactly how it works and I'm learning more about superclasses too.

 

[IvIagnuIvI]

I tried to call that method and it didn't work. The only way to call it is from the class or module itself, for example

Scene_Gameover.method_defined?("main_window") (or with :main_window)

Go to http://homepage2.nifty.com/sakazuki/rde_en/ and download it, it is a Ruby IDE. You can easily test anything there.

class Base
  def something
    p "Base's somehing method called"
  end
end
class Child < Base
  if Base.method_defined?("something") then alias aliased_something something end
  def something
    if Base.method_defined?("something")
      aliased_something
    end
    p "Child's something method called"
    # ...New code...
  end
  
end
a = Child.new
a.something

And when you download it test that code. You'll note that if you change Base's something method's name, it will only call the Child's something method.

Oh and btw, whenever you have a problem with a method, class or whatever take a look at this:
http://www.ruby-doc.org/core/

later