I give you an function exemple:
def debug(var)
raise var.inspect
end
in PHP its simple, I put
function debug($var)
{
var_dump($var);
}
and I just have to include the file where is define this function and it is aviable in all my code where and when I want.
How can I do the same in rails app? I want a function, not a method in class and i want to be able to call it evrywhere in my code.
You can define the method in a module, and then include the module wherever you need access to the method, as follows:
module SomeModule
def debug(var)
raise var.inspect
end
end
And then in another class:
class SomeClass
include SomeModule
def some_method
debug(self)
end
end
It's bad design to add global functions, btw they wont be functions: if you attach something to the global namespace, it will still be a method: remember in Ruby everything is an object.
Attach it to a module.
Example:
module Utils
def self.debug(var)
raise var.inspect
end
end
And use it wherever needed:
Utils.debug(something)
Let's start by saying that what you show as a function in first example is a method.
In Ruby everything is an object. So if you define some method just like in your first example, it still belongs to some object.
irb(main):001:0> self
=> main
irb(main):002:0> self.class
=> Object
You see, even if you just call irb, the context you execute code is an instance of Object class.
So what you actually want is a method which is available globally in scope of Rails application. You can achieve it by including some module right in your application (like in other answers to this question)
However, I suggest different way. Instead of creating a global method, create a class/module with that method. Classes and modules are globally accessible, so you will be able to use it everywhere (see fivedigit's answer for example).
There are no functions in Ruby, what you want is not possible.
App::debug($var)available in all your scope via autoloader