Ruby class declaration question

Question

Can't i do it like this:

class Hardware

before_filter

  def before_filter
    puts "ge"
  end

end

It says before_filter is undefined method or variable when I instantiate it

hd = Hardware.new

because ive seen others put a method name in a class before. Just wondering how it works. Thanks

Answer 1

before_filter is an ActiveRecord class method (see here) and so would only be available if your model inherited from ActiveRecord::Base (or a subclass). Can you be more specific about what you're trying to do?

You might just be looking for:

class Hardware
  def initialize
    super
    before_filter
  end

  protected
  def before_filter
    # ...
  end
end

Answer 2

There's two problems with your code:

1. You are calling a class method, but your are defining an instance method.
2. You are calling the method before it has been defined.

Both of these obviously cannot work.

This would work:

class Hardware
  def self.before_filter
    puts "ge"
  end

  before_filter
end

Answer 3

Either change

def before_filter

to

def self.before_filter

and call it after defined

OR

Comment before_filter

class Hardware
  def before_filter
    puts "ge"
  end
end

and Call like

hd = Hardware.new
hd.before_filter