Question

I’m creating an API in Rails and I’ve run into a situation where I’d like to alert the user that something bad happened by passing them some JSON with an error message. However, I’d also like to re-raise the exception so that Airbrake (formerly Hoptoad) will still catch the error and notify us so that we can look into the problem a bit more.

I’m currently catching the error like so:

begin
  if @myobject.update_attributes(:foo => "bar")
    render :json => @myobject, :status => :ok
  else
    render :json => @myobject.errors, :status => :unprocessable_entity
  end
rescue Exception => e
  render :json => { :errors => { :message => "Uh oh! Something went wrong." } }
  raise e
end

The problem is that my client never gets the JSON message since the raise e stops it from rendering and sends it a generic 500 error.

How should I fix this?

[My Solution]

As suggested by Jordan below, I simply call notify_airbrake(ex) in my code any time that I catch the exception. However, I abstracted it slightly by adding the following to my ApplicationController so that I can easily change from Airbrake to something else in the future:

class ApplicationController < ActionController::Base
  ...

  def notify_exception_service(ex)
    notify_airbrake(ex)
  end

  ...
end

So, instead of notify_airbrake(ex) I just call notify_exception_service(ex).

Answer 1

From the Airbrake gem documentation:

If you want to log arbitrary things which you’ve rescued yourself from a controller, you can do something like this:

rescue => ex
  notify_airbrake(ex)

  flash[:failure] = 'Encryptions could not be rerouted, try again.'
end

The #notify_airbrake call will send the notice over to Airbrake for later analysis. While in your controllers you use the notify_airbrake method, anywhere else in your code, use Airbrake.notify.

You don’t have to re-raise the exception in order to log it with in Airbrake.