From: Robert Klemme <shortcutter@...>
Date: 2006-11-21T02:45:07+09:00
Subject: Re: (Simple?) Why is my rescue clause not catching an exception?

On 20.11.2006 18:34, Wes Gamble wrote:
> All,
> 
> I'm using the Net::HTTP module to fetch resources from the Internet in a 
> Rails application.
> 
> I have a method that does the HTTP request and this action is enclosed 
> in a begin/rescue/end block.  However, when I just did a request and the 
> Internet connectivity went down for a second, the call to 
> "http.request(req)" failed and I didn't see my rescue block get 
> executed.  Instead, it appears that the original exception (from 
> timeout.rb) just bubbles all of the way up the stack and my rescue 
> doesn't seem to catch it.
> 
> Is this because the call to http.request is inside of it's own block and 
> I would need to place a rescue clause in there?
> 
> Here's the guts of my method:
> 
> begin
>   if (theURL.instance_of?(URI::HTTP))
>     req = Net::HTTP::Get.new(theURL.request_uri())
>     res = Net::HTTP.start(theURL.host, theURL.port) {|http|
>       http.request(req)
>     }
>   end
> rescue
>   raise("Unable to get page - please check the URL")
> end
> 
> Thanks,
> Wes
> 

rescue catches StandardError by default only and the exception thrown by 
Net::HTTP is likely some other type not inheriting standard error.

 >> StandardError.ancestors
=> [StandardError, Exception, Object, Kernel]

You need

rescue Exception

Kind regards

	robert