Set this in environment.rb:

   1  ActionController::AbstractRequest.relative_url_root = "/appname/"
   2  ActionController::CgiRequest.relative_url_root = "/appname/"

You might get this error if you’re using Rails Edge: config.breakpoint_server has been deprecated and has no effect:

To fix the error we need to remove the following from config/environments/development.rb:

   1  config.breakpoint_server = true

Next install ruby-debug:

   1  gem install ruby-debug

Then add this to the end of config/environments/development.rb:

   1  require 'ruby-debug'

Next, start your server, and the error should be gone…

To debug your code just add a call to debugger:

   1  class MySillySpace ...
   2    def create
   3      debugger # add this line
   4    end

Now when you access the URL with your browser you’ll have access to the debugger from the console window.

To learn how to use ruby-debug, read this tutorial written by the ruby-debug author.

This snippet explains how to install and use the Rails exception_logger plugin. I’ll also show you how to protect your logs by extending the plugin with basic authentication.

   1  script/plugin source http://svn.techno-weenie.net/projects/plugins
   2  script/plugin install exception_logger

I’m using Rails Edge on this project, so I had to install classic pagination also:

   1  script/plugin install svn://errtheblog.com/svn/plugins/classic_pagination

Next create and execute the migration file:

   1  ./script/generate exception_migration
   2  rake db:migrate

Before starting the server we need to setup the routes:

   1  map.exceptions '/logged_exceptions/:action/:id', :controller => 'logged_exceptions', :action => 'index', :id => nil 

You also need to include the ExceptionLoggable in your ApplicationController:

   1  class ApplicationController < ActionController::Base
   2    include ExceptionLoggable
   3  ...

Start your server and access the exception log at /logged_exceptions.

Exceptions can contain email addresses, passwords, credit card numbers, so you’ll want to protect /logged_exceptions from the public. This can be done by adding the following code to the end of environment.rb:

   1  config.after_initialize do
   2    require 'application' unless Object.const_defined?(:ApplicationController)
   3    LoggedExceptionsController.class_eval do
   4      before_filter :authenticate
   5  
   6      protected
   7  
   8      def authenticate
   9        authenticate_or_request_with_http_basic do |username, password|
  10          username == "foo" && password == "bar"
  11        end
  12      end
  13    end
  14  end

With this code we add a before filter that shows a login dialog to anyone trying to access /logged_exception/. Note that this requires Rails 2.0 basic authentication to work, so make sure you have the proper version installed.

If you’re using Edge Rails and mongrel you might have seen this error:

   1  warning: already initialized constant OPTIONS

There’s a bug report here that explains this problem in detail.

The solution for me was to rerun the freeze command:

   1  rake rails:freeze:edge

You might also get “warning: already initialized constant OPTIONS ” error if you haven’t installed a gem your software relies on. In the following example openssl should be installed:

   1  /usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `gem_original_require’: no such file to load—openssl (MissingSourceFile)

ActiveResource might also be the problem:

   1  gem install activeresource --source http://gems.rubyonrails.org

Use this snippet if you need to use one of the many Rails helpers in controllers or elsewhere:

   1  class Helpers
   2      include Singleton
   3      include ActionView::Helpers::TextHelper
   4      include ActionView::Helpers::UrlHelper
   5      include ActionView::Helpers::DateHelper
   6      include ActionView::Helpers::TagHelper
   7      include ActionView::Helpers::ActiveRecordHelper
   8    end

For example, to obfuscate email use the mail_to helper and set the encoding to JavaScript:

   1  Helpers.instance.mail_to "me@domain.com", "My email", :encode => "javascript"