On 06/11/2014 8:32 AM, "Clint Byrum" <[email protected]> wrote: > > Excerpts from Lee, Alexis's message of 2014-11-05 15:46:43 +0100: > > I'm considering adding a function which takes a list and returns the first > > non-null, non-empty value in that list. > > > > So you could do EG: > > > > some_thing: > > config: > > ControlVIP: > > first_nonnull: > > - {get_param: ControlVIP} > > - {get_attr: [ControlVirtualIP, fixed_ips, 0, ip_address]}]} > > > > I'm open to other names, EG "some", "or", "fallback_list" etc. > > > > Steve Hardy suggested building this into get_attr or Fn::Select. My feeling > > is that those each do one job well right now, I'm happy to take a steer > > though. > > > > What do you think please? > > > > Yes this is super useful for writing responsive, reusable templates. > > I'd like to suggest that this be called 'coalesce' as that is what SQL > calls it.
Although I have no clue why they called it that (colalesce mean join/merge not get first non-null). I'd rather it be called what it does "first_nonnull()" seems more obvious to me. We could also try the conditional as Zane suggested. -Angus > > _______________________________________________ > OpenStack-dev mailing list > [email protected] > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
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