class ActionDispatch::ShowExceptions

catches the exceptions and returns a FAILSAFE_RESPONSE.
If any exception happens inside the exceptions app, this middleware
will send an empty response as result with the correct status code.
If the application returns a “X-Cascade” pass response, this middleware
PATH_INFO to the exception status code and call the rack app.
store the exception in env, rewrite the
of ShowExceptions. Everytime there is an exception, ShowExceptions will
The exceptions app should be passed as parameter on initialization
and calls an exceptions app that will wrap it in a format for the end user.
This middleware rescues any exception returned by the application

def call(env)

def call(env)
  begin
    response  = @app.call(env)
  rescue Exception => exception
    raise exception if env['action_dispatch.show_exceptions'] == false
  end
  response || render_exception(env, exception)
end

def initialize(app, exceptions_app = nil)

def initialize(app, exceptions_app = nil)
  if [true, false].include?(exceptions_app)
    ActiveSupport::Deprecation.warn "Passing consider_all_requests_local option to ActionDispatch::ShowExceptions middleware no longer works"
    exceptions_app = nil
  end
  if exceptions_app.nil?
    raise ArgumentError, "You need to pass an exceptions_app when initializing ActionDispatch::ShowExceptions. " \
      "In case you want to render pages from a public path, you can use ActionDispatch::PublicExceptions.new('path/to/public')"
  end
  @app = app
  @exceptions_app = exceptions_app
end

def pass_response(status)

def pass_response(status)
  [status, {"Content-Type" => "text/html; charset=#{Response.default_charset}", "Content-Length" => "0"}, []]
end

def render_exception(env, exception)

def render_exception(env, exception)
  wrapper = ExceptionWrapper.new(env, exception)
  status  = wrapper.status_code
  env["action_dispatch.exception"] = wrapper.exception
  env["PATH_INFO"] = "/#{status}"
  response = @exceptions_app.call(env)
  response[1]['X-Cascade'] == 'pass' ? pass_response(status) : response
rescue Exception => failsafe_error
  $stderr.puts "Error during failsafe response: #{failsafe_error}\n  #{failsafe_error.backtrace * "\n  "}"
  FAILSAFE_RESPONSE
end

def rescue_responses

def rescue_responses
  ActiveSupport::Deprecation.warn "ActionDispatch::ShowExceptions.rescue_responses is deprecated. " \
    "Please configure your exceptions using a railtie or in your application config instead."
  ExceptionWrapper.rescue_responses
end

def rescue_templates

def rescue_templates
  ActiveSupport::Deprecation.warn "ActionDispatch::ShowExceptions.rescue_templates is deprecated. " \
    "Please configure your exceptions using a railtie or in your application config instead."
  ExceptionWrapper.rescue_templates
end

def status_code(*)

Remove this after 3.2 is out with the other deprecations in this class.
Define this method because some plugins were monkey patching it.

def status_code(*)
end

Modules

Classes