Ruby: How to make a public static method? - ruby-on-rails

Question

In Java I might do:
public static void doSomething();
And then I can access the method statically without making an instance:
className.doSomething();
How can I do that in Ruby? this is my class and from my understanding self. makes the method static:
class Ask
def self.make_permalink(phrase)
phrase.strip.downcase.gsub! /\ +/, '-'
end
end
But when i try to call:
Ask.make_permalink("make a slug out of this line")
I get:
undefined method `make_permalink' for Ask:Class
Why is that if i haven't declared the method to be private?

Answer 1

Your given example is working very well
class Ask
def self.make_permalink(phrase)
phrase.strip.downcase.gsub! /\ +/, '-'
end
end
Ask.make_permalink("make a slug out of this line")
I tried in 1.8.7 and also in 1.9.3
Do you have a typo in you original script?
All the best

Answer 2

There is one more syntax which is has the benefit that you can add more static methods
class TestClass
# all methods in this block are static
class << self
def first_method
# body omitted
end
def second_method_etc
# body omitted
end
end
# more typing because of the self. but much clear that the method is static
def self.first_method
# body omitted
end
def self.second_method_etc
# body omitted
end
end

Answer 3

Here's my copy/paste of your code into IRB. Seems to work fine.
$ irb
1.8.7 :001 > class Ask
1.8.7 :002?>
1.8.7 :003 > def self.make_permalink(phrase)
1.8.7 :004?> phrase.strip.downcase.gsub! /\ +/, '-'
1.8.7 :005?> end
1.8.7 :006?>
1.8.7 :007 > end
=> nil
1.8.7 :008 > Ask.make_permalink("make a slug out of this line")
=> "make-a-slug-out-of-this-line"
Seems to work. Test it out in your irb as well, and see what results you're getting. I'm using 1.8.7 in this example, but I also tried it in a Ruby 1.9.3 session and it worked identically.
Are you using MRI as your Ruby implementation (not that I think that should make a difference in this case)?
In irb make a call to Ask.public_methods and make sure your method name is in the list. For example:
1.8.7 :008 > Ask.public_methods
=> [:make_permalink, :allocate, :new, :superclass, :freeze, :===,
...etc, etc.]
Since you also marked this as a ruby-on-rails question, if you want to troubleshoot the actual model in your app, you can of course use the rails console: (bundle exec rails c) and verify the publicness of the method in question.

Answer 4

I am using ruby 1.9.3 and the program is running smoothly in my irb as well.
1.9.3-p286 :001 > class Ask
1.9.3-p286 :002?> def self.make_permalink(phrase)
1.9.3-p286 :003?> phrase.strip.downcase.gsub! /\ +/, '-'
1.9.3-p286 :004?> end
1.9.3-p286 :005?> end
=> nil
1.9.3-p286 :006 > Ask.make_permalink("make a slug out of this line")
=> "make-a-slug-out-of-this-line"
It's also working in my test script. Nothing wrong with your given code.It's fine.