Try using Ruby's exception handling:

begin
  @new_ipv4 = Ipv4addr.find(IPAddr.new(params[:ipv4addr][:id]).to_i)
rescue
  # Code to add data to database
end

A little more info:

http://www.rubycentral.com/book/tut_exceptions.html

On 3/16/06, Franz Bettag <fbettag / qs-housing.net> wrote:
> Hi guys,
>
> uhm how to fetch out a RecordNotFound?
>
> i have this here
>
> @new_ipv4 = Ipv4addr.find(IPAddr.new(params[:ipv4addr][:id]).to_i)
>
> but at this line it gives an error RecordNotFound. But this is okay! But
> now i want the application to do something special like adding the not
> found IPaddr to the database.. But how? since it stops at this line =)
>
> Thanks in advance!
> --
>
>
> Mit freundlichen Grüßen
>
> Franz Bettag
>
> ____________________________
> QS Housing
> Franz Bettag
> Ludwigstr. 45-47
> 90402 Nnberg
> http://www.qs-housing.net
>
> Tel: +49 1805 737376 664
> Fax: +49 1805 737376 665
>
>