Ruby on Rails错误处理，捕获错误和消息

Question

I'm trying to figure out the best way to catch a specific error thrown AND the error's message in Ruby on Rails. My use case is that I encounter a timeout error every now and then which is thrown with a general error and I want to treat the timeout error differently than other errors within the same general error. I'm not sure what other type of errors could be thrown in the general error but I assume more of them exist. I have some sample code below of how I'm currently handling it, but I was thinking there might be a better way which I haven't found yet?

tries = 0
begin
  tries += 1
  <code>
rescue Foo::Bar => e
  case e.to_s
  when 'More specific timeout error message'
    retry unless tries >= 5
  else
    # Let me see other error messages
    log.info("Error: #{e.to_s}")
  end
end

Answer 1

You can use multi rescue , to handle different errors.

begin
  # DO SOMETHING
rescue Net::Timeout => e # change it to the error your want to catch, check the log.
  # handle it
rescue SyntaxError => e # just an example 
  # handle it
rescue => e # any error that not catch by above rescue go here.
  # handle it
end

Read more: http://phrogz.net/programmingruby/tut_exceptions.html

You can try Rollbar , it help report error on production.

Answer 2

Take a look at retriable gem . It seems like a good fit for what you're proposing. Usually you'd rescue from an specific error type, but retriable also gives you the choice to rescue based on the error message.

begin
  Retriable.retriable on: { Foo::Bar => /More specific timeout error message/ }, tries: 3 do
    # will retry if an error of type Foo::Bar is raised
    # and its message matches /More specific timeout error message/

    # code here... 
  end
rescue => e # rescue for everything else
  puts e.message # same as e.to_s
end