notification all errors and keep different rescues

Question

I'm trying to send all rails errors as a notification, without disturbing other rescues.

ApplicationController:

class ApplicationController < ActionController::Base
around_filter :notify_errors

  def notify_errors
    begin
      yield
    rescue => e
      Notification.send_to(:admin, e)
    end
  end
end

SomeController function:

  def send_date
    date = Date.strptime('10/100/2013', '%m/%d/%Y')
    render json: {success: true, date: date}
  rescue ArgumentError
    render json: {success: false, msg: 'Bad date'}
  end

I get the "Bad date" json but not the Notification.send_to(:admin, e).

score 2 · Answer 1 · answered Jul 18 '15 at 13:00

2

Raise again your exception.

def send_date
    date = Date.strptime('10/100/2013', '%m/%d/%Y')
    render json: {success: true, date: date}
rescue ArgumentError => e
    render json: {success: false, msg: 'Bad date'}
    raise e
end

answered Jul 18 '15 at 13:00

coorasse

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Really great! Is there a way to make it easier for each reraise error? A global solution or a function? – Shalev Shalit Jul 18 '15 at 14:31

score 1 · Accepted Answer · answered Jul 18 '15 at 19:31

Is there a way to make it easier for each reraise error? A global solution or a function?

You could monkeypatch raise.

module RaiseNotify
  def raise(msg_or_exc, msg=msg_or_exc, trace=caller)
    Notification.send_to(:admin, msg_or_exc) if msg_or_exc.kind_of? StandardError
    fail msg_or_exc, msg=msg_or_exc, trace
  end
end

module Kernel
  include RaiseNotify
end

I haven't tested this, it would probably have impact beyond Rails, and I think it's a bad idea! Personally, I'd just call the notification code inside the initial rescue clause.

def send_date
  date = Date.strptime('10/100/2013', '%m/%d/%Y')
  render json: {success: true, date: date}
rescue ArgumentError => e
  Notification.send_to(:admin, e)
  render json: {success: false, msg: 'Bad date'}
end

This may be shortened with a method:

def rescue_with_notify error_type=ArgumentError
  *yield 
rescue error_type => e      
  Notification.send_to(:admin, e)
  [nil,false]
end

The idea would be to wrap what you wish to check, and respond with an array, the end of which would be the "success" flag.

def send_date date_string
  date,success = rescue_with_notify do
    Date.strptime(date_string, '%m/%d/%Y') 
  end
  success = true if success.nil?
  date ||= "Bad date"
  render json: {success: success, date: date} 
end

But this is adding complexity and maybe extra lines for very little in return. I'd stick with pasting the notification code into rescue clauses as and when it's required.

@TheShalit Glad it could help. I got the idea from Avdi Grimm's Exceptional Ruby, it's worth a read if you get the chance. — ian, Jul 19 '15 at 18:25

notification all errors and keep different rescues

2 Answers2