#53 Handling Exceptions (revised)

Apr 20, 2013 | 11 minutes | Controllers, Routing, Production, Rack

By default, Rails will render a static error file when an exception occurs in production. Here you will learn how to fully customize this behavior and render dynamic error pages.

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          terminal
        
rake middleware
rails g controller errors
curl localhost:3000/errors/404 > public/404.html

          config/environments/development.rb
        
config.consider_all_requests_local = false

          config/application.rb
        
config.action_dispatch.rescue_responses["ProductsController::Forbidden"] = :forbidden

config.exceptions_app = self.routes

          config/routes.rb
        
match '(errors)/:status', to: 'errors#show', constraints: {status: /\d{3}/} # via: :all

          errors_controller.rb
        
def show
  @exception = env["action_dispatch.exception"]
  respond_to do |format|
    format.html { render action: request.path[1..-1] }
    format.json { render json: {status: request.path[1..-1], error: @exception.message} }
  end
end

          views/errors/403.html.erb
        
<h1>Forbidden.</h1>
<% if @exception %>
  <p><%= @exception.message %></p>
<% else %>
  <p>You are not authorized to perform that action.</p>
<% end %>

          application_controller.rb
        
# alternative to overriding exceptions
rescue_from "Exception", with: :forbidden

private

def forbidden(exception)
  render text: exception.message
end