How to capture correctly a specific exception

I a using delayed_job, and I am raising an exception this way :

config/initializers/custom_exceptions.rb
   class RemoteLockerException < StandardError; end
   class RemoteLockerDenied < StandardError; end

lib/instruction_request_job.rb
class InstructionRequestJob < Struct.new(:style, :request_id)
   def perform
....

  connector = RemoteContainerServer::Connector.create!(remote_container)
  raise Exceptions::RemoteLockerDenied , "RemoteLockerDenied" if connector.nil?

....

  requestId = connector.request_job(user, remote_container)
  raise Exceptions::RemoteContainerException, "RemoteContainerException" if requestId.nil?

...
  end

there is a hook for any exception raised, to trap ALL the errors
and do something according to the raised exception , i.e. :

    def error(job, exception)
      case exception
      when "RemoteContainerDenied"
        .. do something
      when "RemoteContainerException"
        .. do something else ......
      end
    end

I am new to 'exception raising' ... so I initially thought I could
trap the exception message : "RemoteLockerDenied" or
"RemoteContainerException" as case parameter exception
but it seems not working that way ...

when raised , I get #<NameError: uninitialized constant
InstructionRequestJob::Exceptions> which is the exception type, not
the message ... I may be ( surely) totally wrong ..... how should I
proceed ?

I a using delayed_job, and I am raising an exception this way :

config/initializers/custom_exceptions.rb
class RemoteLockerException < StandardError; end
class RemoteLockerDenied < StandardError; end

This should define just RemoteLockerDenied, not
Exceptions::RemoteLockerDenied.

there is a hook for any exception raised, to trap ALL the errors
and do something according to the raised exception , i.e. :

def error\(job, exception\)
  case exception
  when &quot;RemoteContainerDenied&quot;
    \.\. do something
  when &quot;RemoteContainerException&quot;
    \.\. do something else \.\.\.\.\.\.
  end
end

Your whens should use the exception class, not the name, ie

when RemoteLockerDenied instead of when 'RemoteLockerDenied'

Fred

Thanks Fred

I believe I can pass parameters to the Exception class for fine grain
processing
will read more about it .. any better link than Rials doc ,

Thanks Fred

I believe I can pass parameters to the Exception class for fine grain
processing
will read more about it .. any better link than Rials doc ,

You probably want some pure ruby documentation - this isn't rails
specific at all.
Your subclasses of StandardError can store as many extra bits of
information about the error that occurred as you want - just override
the initialize method to stash the information in an instance variable
or something like that

Fred

got it .. and it's running well , may be not the best coding , but it
runs ....

in my config/initializers/custom_exceptions.rb

Module Exceptions
  class RemoteContainerDenied < StandardError
    def initialize(msg, remote_container_id, request_id , user_id)
        super(msg)
        @message = msg
        @request_id = request_id
        @remote_container_id = remote_container_id
        @user_id = user_id
    end
    def message; @message + "remote_container_id:
#{@remote_container_id} , requestId: #{@request_id}"; end
    def remote_container_id; @remote_container_id; end
    def request_id; @request_id; end
    def user_id; @user_id; end
  end
end

raised with :
raise(RemoteContainerDenied.new("Access denied",
remote_container_id[:id], request[:id], user[:id] ) if response.nil?

et voilà ...

then I can trap these exceptions in delayed_job ( error hook) and act
according to the exception :

def error(job, exception)
    case exception
    when RemoteLockerDenied
        AdminMailer.....

very awesome

by the way, if you were to write

attr_reader :remote_container_id, :request_id, :user_id then that
would write your reader methods for you

Fred

Hi Guys
Trying to copy your code but not having any luck

All I get is "wrong number of arguments (3 for 0..1)" in the
initialize call back actually referring to the .new call in the raise
Can't see what I'm doing wrong.

Any help greatly appreciated

regards

dukha

module Exceptions
  class IncorrectArrayFormatInYamlFile < StandardError
    attr_accessible :line_number, :translation_file_id

    def initialize( msg, line_number, translation_file_id)
      super(msg)
      @line_number = line_number
      @translation_file_id =translation_file_id
    end

    def file_name
      return
TranslationFile.find(@translation_file_id).english_translation_file_name
    end

    def message
      message = @message + "line number: #{@line_number}, file:
#{file_name}."
    end

  end
end

msg = "This file is using incorrect array format. Change file format
from \" - <array_element>\" to key: [element1,element2..]. This
element is on line " + line_sequence.to_s + " in " +
TranslationFile.find(translation_file_id).english_translation_file_name
raise Exceptions::IncorrectArrayFormatInYamlFile.new msg,
line_sequence, translation_file_id