[RFC 1/1] virxml: Accept 'default' for virTristate* properties

[Andrea Bolognani]

On Thu, Mar 24, 2022 at 12:42:12PM +0100, Peter Krempa wrote:
> On Thu, Mar 24, 2022 at 12:02:05 +0100, Martin Kletzander wrote:
> > On Thu, Mar 24, 2022 at 10:32:51AM +0000, Andrea Bolognani wrote:
> > > On Thu, Mar 24, 2022 at 09:58:28AM +0100, Martin Kletzander wrote:
> > > > I would rather change this flag to something like
> > > > VIR_XML_PROP_ALLOW_ZERO and only allow parsing default values with this
> > > > flag making the callers be able to opt in for this behaviour rather then
> > > > all the others having to opt out.
> > >
> > > Yeah, this sounds better from the caller's point of view, but it
> > > would require adding a check to make sure that only one of
> > > VIR_XML_PROP_NONZERO and VIR_XML_PROP_ALLOW_ZERO has been passed.
> > > I'll see how clunky that looks.
> >
> > I meant only keeping the new one, although I must admit I completely
> > missed the fact that it is used properly somewhere else.  If we went
> > that way then the flag might itself be a tristate enum "default,
> > allow_zero, non_zero" where default is different for numbers and enums,
> > but that seems even clunkier and I don't like that myself.
>
> Alternatively introduce a new helper e.g. virXMLPropTristateBoolDefault
> which will allow also the 'default' value to be specified explicitly.
>
> In such case we can document the difference in the comment and don't
> have to touch every other usage.

Yeah, I thought of that approach too and it sounds like it would be
the least terrible one. I'm going to give it a try and report back :)

Thanks for all your input so far!

-- 
Andrea Bolognani / Red Hat / Virtualization