Install - Config - Support

---

ExceptionHandler helps you can create custom 404 & 500 production error pages (adapted from 1 & 2).

ExceptionHandler is the only production-ready custom error page solution for Rails 4 & 5.

---

Customize 404 and 500 error pages to be branded to your application in production:

  Responsive     Branded Error Pages     Middleware Exception Handling     Fully Customizable  

The most feature-rich, stable & effective solution for custom error pages in Rails 4 & 5.

---

  New Controller     New Middleware     Full Test Suite     FULLY Rails 4 & 5 Compatible  

Brand new controller, middleware & options have made ExceptionHandler even more powerful & efficient. Now you can use ExceptionHandler directly with a single click -- plug and play custom exception pages:

ExceptionHandler uses config.exceptions_app to catch & send errors to the exceptions controller.

It uses data stored in Rack (message, details, user agent) to populate its custom view. This gives you the ability to maintain your branding even when your app experiences an exception.

---

The power of ExceptionHandler lies in its capacity to access the ActiveDispatch::ShowExceptions middleware:

Rails invokes config.exceptions_app whenever an exception is raised.

ExceptionHandler injects our ExceptionController into this hook to provide the most efficient response:

config.exceptions_app sets the exceptions application invoked by the ShowException middleware when an exception happens. Defaults to ActionDispatch::PublicExceptions.new(Rails.public_path).

As opposed to other exception suites (which use the routes), this gives you DIRECT access to the exception through the middleware stack, straight to the ExceptionController:

ExceptionHandler uses custom middleware to extract all the exception data for the request. Not only is this the most succinct, efficient way to do this, it also allows you to customize the entire fault-recovery process.

It's completely unique - the only professional solution to catch, process & handle exceptions in Rails.

---

You Don't Need Any Configuration To Run ExceptionHandler

gem install "exception_handler"

or

gem 'exception_handler', '~> 0.5.0' #-> Gemfile

ExceptionHandler's new config system (introduced in 0.4.7) stores all the defaults - you just need to install the gem & let it run.

If you want to change any settings (detailed below), you simply need to change config/application.rb / config/environments/your_env.rb. The POWER of this new config system means you're able to deploy ExceptionHandler in the most unobtrusive, versatile way possible.

---

ExceptionHandler 0.5 has the SIMPLEST config possible...

The MAGIC is that it uses environment files.

You can apply the above options to any of Rails' environment files, allowing you to customize the ExceptionHandler gem without inducing ANY overhead. Initializer files just get in the way.

IMPORTANT

If you're upgrading from >= 0.4.7, you need to remove your exception_handler initializer.

We've changed the load process to use Rails app config - you don't need the exception_handler initializer any more

---

As can be seen in the config class, the following are all the options exception_handler accepts:

# config.rb
DEFAULTS = {
  dev:    false, #-> defaults to "false" for dev mode
  db:     false, #-> defaults to :errors if true, else input "table_name" as string
  email:  false, #-> need to integrate
  social: {
    :facebook   =>  'frontline.utilities', #-> Facebook handle
    :twitter    =>  'frontlineutils',      #-> Twitter handle
    :youtube    =>  'frontlineutils',      #-> YouTube handle
    :linkedin   =>  'frontline-utilities', #-> LinkedIn handle
    :fusion     =>   'frontlineutils',     #-> Fusion handle
    :url => {                             
      :facebook   =>  'https://facebook.com',          #-> no need to edit
      :twitter    =>  'http://twitter.com',            #-> no need to edit
      :youtube    =>  'https://youtube.com/user',      #-> no need to edit
      :linkedin   =>  'https://linkedin.com/company',  #-> no need to edit
      :fusion     =>  'https://frontlinefusion.com',   #-> no need to edit              
    },
  },
  layouts: {
    '404' => nil, #-> 404 Callback (needs improving big time) Use the following: '404' => <<-EOF redirect_to root_url, notice: "Hello" EOF
    '400' => nil, #-> layout for 400 error code (404 should only be used as response)
    '500' => 'exception'
  },
}

The above are defaults.

You can change the options for each environment file:

• config/application.rb
• config/environments/development.rb
• config/environments/production.rb
• config/environments/staging.rb

The benefit of this is that it gives you the ability to customize ExceptionHandler for any of your environments. Contrary to a shitty initializer, you're able to sculpt the gem to work FOR YOU.

---

Want to test in the dev environment?

#config/application.rb
config.exception_handler = {
  dev: true # -> Runs in development mode WITHOUT changing the app environment files
}

config.exceptions_app only works when you have config.consider_all_requests_local = true, which is true in development:

config.consider_all_requests_local is a flag. If true then any error will cause detailed debugging information to be dumped in the HTTP response, and the Rails::Info controller will show the application runtime context in /rails/info/properties. True by default in development and test environments, and false in production mode. For finer-grained control, set this to false and implement local_request? in controllers to specify which requests should provide debugging information on errors.

If you wish to test ExceptionHandler in development, you'll have to use the dev: true option in your exception_handler config, or change config.consider_all_requests_local = true in config/development.rb.

---

One of the most critial aspects of ExceptionHandler is the custom Exception layout.

If you want to change the layout (for 500 error pages), you need to use the following:

You'll need to generate it into your application before being able to edit:

---

ExceptionHandler comes with its own inbuilt views & controller.

If you want to change it, you need to add the views into your app with the generator

$ rails generate exception_handler:views                                            #-> controller, models, helpers, views & assets
$ rails generate exception_handler:views -v views controllers models helpers assets #-> remove as appropriate to install individual assets

--

ExceptionHandler uses exceptions#show -- located in app/views/exception_handler/show.html.erb designed to work for all exceptions.

By default, it is split for use with different layouts, data being available to both.

This works exactly the same as the other views in your app (IE the exceptions controller invokes the show action)

---

If you want to store exceptions in your db, you will need to set up a migration:

$ rails generate exception_handler:migration
$ rake db:migrate

You will also need to ensure your config db option is either true or "table_name":

IMPORTANT

ExceptionHandler's new config system is environment agnostic.

Where you declare your db setting will change depending on your environment

If you declare db in application.rb, it will be applicable for all environments; only declaring in production.rb will set it for production only.

---

Github Issue (1hr)	Stackoverflow (24hrs)

We use ExceptionHandler in production, so we have a vested interest in keeping it running smoothly.

Asking in either of the above services will give you a response. Don't be shy, we want to make this the best exception handling middleware for Rails.

--

0.5.1

• Next release

0.5.0

• Added locales
• Email notifications
• Full test suite (finally)
• Rails 4.2 & Rails 5.0 native (request.env fix)
• Controller fixed
• DB fixed
• Legacy initializer support (more)
• Rails asset management improvement
• Cut out most dev files from gem (drastic reduction in gem size)

0.4.7

• New config system (more)
• Fixed controller layout issues
• Streamlined middleware
• New layout & interface implementation

---

© 2016 R Peck for FL