How do I raise an exception in Rails so it behaves like other Rails exceptions?

Question

I would like to raise an exception so that it does the same thing a normal Rails exception does. Specially, show the exception and stack trace in development mode and show "We're sorry, but something went wrong" page in production mode.

I tried the following:

raise "safety_care group missing!" if group.nil? 

But it simply writes "ERROR signing up, group missing!" to the development.log file

Answer 1

You don't have to do anything special, it should just be working.

When I have a fresh rails app with this controller:

class FooController < ApplicationController   def index     raise "error"   end end 

and go to http://127.0.0.1:3000/foo/

I am seeing the exception with a stack trace.

You might not see the whole stacktrace in the console log because Rails (since 2.3) filters lines from the stack trace that come from the framework itself.

See config/initializers/backtrace_silencers.rb in your Rails project

Answer 2

You can do it like this:

class UsersController < ApplicationController   ## Exception Handling   class NotActivated < StandardError   end    rescue_from NotActivated, :with => :not_activated    def not_activated(exception)     flash[:notice] = "This user is not activated."     Event.new_event "Exception: #{exception.message}", current_user, request.remote_ip     redirect_to "/"   end    def show       // Do something that fails..       raise NotActivated unless @user.is_activated?   end end 

What you're doing here is creating a class "NotActivated" that will serve as Exception. Using raise, you can throw "NotActivated" as an Exception. rescue_from is the way of catching an Exception with a specified method (not_activated in this case). Quite a long example, but it should show you how it works.

Best wishes,
Fabian