How to capture correctly a specific exception

Rails
1

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 ?

2

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 ,

3

On May 22, 4:36pm, Erwin [email protected] wrote:

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.

end
end

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

when RemoteLockerDenied instead of when ‘RemoteLockerDenied’

Fred

4

On May 23, 7:11am, Erwin [email protected] wrote:

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

5

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 voil …

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

6

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

On May 23, 10:36pm, Frederick C. [email protected]

7

On May 23, 11:39am, Erwin [email protected] wrote:

def remote_container_id; @remote_container_id; end
def request_id; @request_id; end
def user_id; @user_id; end

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