Add Rescue From as a rails til

README.md

@@ -7,7 +7,7 @@ variety of languages and technologies. These are things that don't really
 warrant a full blog post. These are mostly things I learn by pairing with
 smart people at [Hashrocket](http://hashrocket.com/).
 
-_353 TILs and counting..._
+_354 TILs and counting..._
 
 ---
 
@@ -222,6 +222,7 @@ _353 TILs and counting..._
 - [Migrating Up Down Up](rails/migrating-up-down-up.md)
 - [Params Includes Submission Button Info](rails/params-includes-submission-button-info.md)
 - [Pretend Generations](rails/pretend-generations.md)
+- [Rescue From](rails/rescue-from.md)
 - [Retrieve An Object If It Exists](rails/retrieve-an-object-if-it-exists.md)
 - [Select A Select By Selector](rails/select-a-select-by-selector.md)
 - [Select Value For SQL Counts](rails/select-value-for-sql-counts.md)

rails/rescue-from.md

@@ -0,0 +1,21 @@
+# Rescue From
+
+The
+[`rescue_from`](http://api.rubyonrails.org/classes/ActiveSupport/Rescuable/ClassMethods.html)
+method, provided by `ActiveSupport`, is a handy way to provide a catch-all
+response to a particular exception.
+
+For instance, if many of the controllers in your application raise a
+`User::NotAuthorized` error for unauthorized requests, the
+`ApplicationController` can provide a unified response. This will help dry
+up your controllers and prevent any potential inconsistencies.
+
+```ruby
+class ApplicationController < ActionController::Base
+  rescue_from User::NotAuthorized do |exception|
+    # respond with some Not Authorized page
+  end
+
+  ...
+end
+```