Remove unnecessary / confusing code in example

guides/source/action_controller_overview.md

@@ -561,7 +561,7 @@ Note that while for session values you set the key to `nil`, to delete a cookie
 Rendering xml and json data
 ---------------------------
 
-ActionController makes it extremely easy to render `xml` or `json` data. If you generate a controller using scaffolding then it would look something like this:
+ActionController makes it extremely easy to render `xml` or `json` data. If you've generated a controller using scaffolding, it would look something like this:
 
 ```ruby
 class UsersController < ApplicationController
@@ -576,7 +576,7 @@ class UsersController < ApplicationController
 end
 ```
 
-Notice that in the above case code is `render xml: @users` and not `render xml: @users.to_xml`. That is because if the input is not string then rails automatically invokes `to_xml` .
+You may notice in the above code that we're using `render xml: @users`, not `render xml: @users.to_xml`. If the object is not a String, then Rails will automatically invoke `to_xml` for us.
 
 Filters
 -------
@@ -599,15 +599,6 @@ class ApplicationController < ActionController::Base
       redirect_to new_login_url # halts request cycle
     end
   end
-
-  # The logged_in? method simply returns true if the user is logged
-  # in and false otherwise. It does this by "booleanizing" the
-  # current_user method we created previously using a double ! operator.
-  # Note that this is not common in Ruby and is discouraged unless you
-  # really mean to convert something into true or false.
-  def logged_in?
-    !!current_user
-  end
 end
 ```