Q:

redirect_to != return

I'm looking for some clarification regarding the behaviour of redirect_to.
I have this code:
if some_condition
   redirect_to(path_one)
end

redirect_to(path_two)

If some_condition == true I get this error:

Render and/or redirect were called multiple times in this action. Please note that you may only call render OR redirect, and at most once per action. 

It seems that the method continues to execute after the redirect_to call.  Do I need to write code like this:
if some_condition
   redirect_to(path_one)
   return
end

redirect_to(path_two)

A:

Yes, you need to return from method when doing redirect. It actually only adds appropriate headers for the response object.
You can write more rubyish way:
if some_condition
    return redirect_to(path_one)
end

redirect_to(path_two)

or other way:
return redirect_to(some_condition ? path_one : path_two)

or another way:
redirect_path = path_one

if some_condition
    redirect_path = path_two
end

redirect_to redirect_path

A:

From http://api.rubyonrails.org/classes/ActionController/Base.html:

If you need to redirect on the
  condition of something, then be sure
  to add “and return” to halt execution.

def do_something
  redirect_to(:action => "elsewhere") and return if monkeys.nil?
  render :action => "overthere" # won't be called if monkeys is nil
end

A:

You can also do
redirect_to path_one and return

which reads nice.

