Catch all exceptions in the rail controller

Question

Is there a way to catch all thrown exceptions in the rails controller, for example:

def delete schedule_id = params[:scheduleId] begin Schedules.delete(schedule_id) rescue ActiveRecord::RecordNotFound render :json => "record not found" rescue ActiveRecord::CatchAll #Only comes in here if nothing else catches the error end render :json => "ok" end 

thank

Answer 1

 begin # do something dodgy rescue ActiveRecord::RecordNotFound # handle not found error rescue ActiveRecord::ActiveRecordError # handle other ActiveRecord errors rescue # StandardError # handle most other errors rescue Exception # handle everything else raise end 

Answer 2

You can also define a rescue_from method.

 class ApplicationController < ActionController::Base rescue_from ActionController::RoutingError, :with => :error_render_method def error_render_method respond_to do |type| type.xml { render :template => "errors/error_404", :status => 404 } type.all { render :nothing => true, :status => 404 } end true end end 

Depending on your purpose, you may also consider the possibility of handling exceptions for each controller. Instead, use something like exception_handler to sequentially manage exception responses. As a bonus, this approach will also handle exceptions that occur at the middleware level, such as parsing queries or database connection errors that your application does not see. The stone exception_notifier may also be of interest.

Answer 3

You can catch exceptions by type:

 rescue_from ::ActiveRecord::RecordNotFound, with: :record_not_found rescue_from ::NameError, with: :error_occurred rescue_from ::ActionController::RoutingError, with: :error_occurred # Don't resuce from Exception as it will resuce from everything as mentioned here "http://stackoverflow.com/questions/10048173/why-is-it-bad-style-to-rescue-exception-e-in-ruby" Thanks for @Thibaut Barrère for mention that # rescue_from ::Exception, with: :error_occurred protected def record_not_found(exception) render json: {error: exception.message}.to_json, status: 404 return end def error_occurred(exception) render json: {error: exception.message}.to_json, status: 500 return end 

Answer 4

rescue without arguments will fix any error.

So you need to:

 def delete schedule_id = params[:scheduleId] begin Schedules.delete(schedule_id) rescue ActiveRecord::RecordNotFound render :json => "record not found" rescue #Only comes in here if nothing else catches the error end render :json => "ok" end 

Answer 5

In fact, if you really want to catch everything, you simply create your own exception application that allows you to customize the behavior that is usually handled by the PublicExceptions middleware: https://github.com/rails/rails/blob/4-2- stable / actionpack / lib / action_dispatch / middleware / public_exceptions.rb

• stack location https://github.com/rails/rails/blob/4-2-stable/railties/lib/rails/application/default_middleware_stack.rb#L98-L99
• setting https://github.com/rails/rails/blame/4-2-stable/guides/source/configuring.md#L99
  • which can be as simple as using routes http://blog.plataformatec.com.br/2012/01/my-five-favorite-hidden-features-in-rails-3-2/ or a user controller (but see . https://github.com/rails/rails/pull/17815 for reasons not using routes)

A bunch of other answers contain gems that do this for you, but there is no reason why you cannot just look at them and do it yourself.

Caution: make sure you never throw an exception in your exception handler. Otherwise you will get the ugly FAILSAFE_RESPONSE https://github.com/rails/rails/blob/4-2-stable/actionpack/lib/action_dispatch/middleware/show_exceptions.rb#L4-L22

BTW, the behavior in the controller comes from the savior: https://github.com/rails/rails/blob/4-2-stable/activesupport/lib/active_support/rescuable.rb#L32-L51