RescueFrom

gem 'rescue_from'

class ApplicationController < ActionController::Base
  # Override the rescued hook which is called when configuration.raise_exceptions is false
  # (See 'Controller hook')
  #
  # def openstax_exception_rescued(exception_proxy, did_notify)
  #   app_name = openstax_rescue_config.app_name
  #     # RescueFrom.configuration private method available to you
  #
  #   respond_to do |f|
  #     f.xml { render plain: "I respond strangely to the XML format!",
  #                    status: exception_proxy.status }
  #   end
  # end
end

# Use OpenStax::RescueFrom.register_exception(exception_constant_or_string, options = {})
# to register new exceptions or override the options of existing ones

OpenStax::RescueFrom.register_exception(SecurityTransgression, status: 403,
                                                               extras: -> (exception) {
                                                                 { headers: exception.response.headers }
                                                               })

OpenStax::RescueFrom.register_exception('ActiveRecord::RecordNotFound', notify: false,
                                                                        status: 404)

OpenStax::RescueFrom.configure do |config|
  config.raise_exceptions = ![false, 'false'].include?(ENV['RAISE_EXCEPTIONS']) ||
                              Rails.application.config.consider_all_requests_local

  config.app_name = ENV['APP_NAME']
  # Can be a name, or a web/email address. See 'View helper' below
  config.contact_name = ENV['EXCEPTION_CONTACT_NAME']

  # To use ExceptionNotifier add `gem 'exception_notification'` to your Gemfile and then:
  # config.notify_proc = ->(proxy, controller) do
  #   ExceptionNotifier.notify_exception(
  #     proxy.exception,
  #     env: controller.request.env,
  #     data: {
  #       error_id: proxy.error_id,
  #       class: proxy.name,
  #       message: proxy.message,
  #       first_line_of_backtrace: proxy.first_backtrace_line,
  #       cause: proxy.cause,
  #       dns_name: resolve_ip(controller.request.remote_ip),
  #       extras: proxy.extras
  #     },
  #     sections: %w(data request session environment backtrace)
  #   )
  # end
  # config.notify_background_proc = ->(proxy) do
  #   ExceptionNotifier.notify_exception(
  #     proxy.exception,
  #     data: {
  #       error_id: proxy.error_id,
  #       class: proxy.name,
  #       message: proxy.message,
  #       first_line_of_backtrace: proxy.first_backtrace_line,
  #       cause: proxy.cause,
  #       extras: proxy.extras
  #     },
  #     sections: %w(data environment backtrace)
  #   )
  # end
  # config.notify_rack_middleware = ExceptionNotification::Rack
  # config.notify_rack_middleware_options = {
  #   email: {
  #     email_prefix: "[#{config.app_name}] (#{ENV['APP_ENV']}) ",
  #     sender_address: ENV['EXCEPTION_SENDER'],
  #     exception_recipients: ENV['EXCEPTION_RECIPIENTS']
  #   }
  # }
  # URL generation errors are caused by bad routes, for example, and should not be ignored
  # ExceptionNotifier.ignored_exceptions.delete("ActionController::UrlGenerationError")

  # To use Raven (Sentry) add `gem 'sentry-raven', require: 'raven/base'` to your Gemfile and then:
  # config.notify_proc = -> do |proxy, controller|
  #   extra = {
  #     error_id: proxy.error_id,
  #     class: proxy.name,
  #     message: proxy.message,
  #     first_line_of_backtrace: proxy.first_backtrace_line,
  #     cause: proxy.cause,
  #     dns_name: resolve_ip(controller.request.remote_ip)
  #   }
  #   extra.merge!(proxy.extras) if proxy.extras.is_a? Hash
  #
  #   Raven.capture_exception(proxy.exception, extra: extra)
  # end
  # config.notify_background_proc = -> do |proxy|
  #   extra = {
  #     error_id: proxy.error_id,
  #     class: proxy.name,
  #     message: proxy.message,
  #     first_line_of_backtrace: proxy.first_backtrace_line,
  #     cause: proxy.cause
  #   }
  #   extra.merge!(proxy.extras) if proxy.extras.is_a? Hash
  #
  #   Raven.capture_exception(proxy.exception, extra: extra)
  # end
  # require 'raven/integrations/rack'
  # config.notify_rack_middleware = Raven::Rack

  config.html_error_template_path = 'errors/any'
  config.html_error_template_layout_name = 'application'
end

# Exceptions in controllers might be reraised or not depending on the settings above
ActionController::Base.use_openstax_exception_rescue

# RescueFrom always reraises background exceptions so that the background job may properly fail
ActiveJob::Base.use_openstax_exception_rescue

#
#             -- Mixed in Controller module instance method --
#
#       -- this method is ONLY called when Exceptions are not raised --
#
# -- check your OpenStax::RescueFrom.configuration.raise_exceptions setting --
#
# Params:
#   exception_proxy - an OpenStax::RescueFrom::ExceptionProxy wrapper around
#     the exception
#   did_notify - true if the exception was sent out to notification channels
#     such as email or the log file
#

def openstax_exception_rescued(exception_proxy, did_notify)
  @message = exception_proxy.friendly_message
  @status = exception_proxy.status
  @error_id = exception_proxy.error_id
  @did_notify = did_notify

  respond_to do |f|
    f.html { render template: openstax_rescue_config.html_error_template_path,
                    layout: openstax_rescue_config.html_error_template_layout_name,
                    status: exception_proxy.status }
    f.json { render json: { error_id: exception_proxy.error_id }
                    status: exception_proxy.status }
    f.all { head exception_proxy.status }
  end
end

# Just override this method in your own controller if you wish

OpenStax::RescueFrom.configure do |config|
  config.html_error_template_path = 'my/path'
  config.html_error_template_layout_name = 'my_layout'
end