[Koha-devel] Bug 18539 - Forbid Koha::Objects->find calls in list context

[Julian Maurice]

I know that find is supposed to retrieve only one result. That's why we
shouldn't have to care about the context, it's never ambiguous.
I should be allowed to write

    push @patrons, Koha::Patrons->find($borrowernumber);

without specifying that I only want one record (using 'scalar')

Le 13/12/2017 à 14:50, Marcel de Rooy a écrit :
> Find is supposed for retrieving one result not multiple ones. Use search
> instead.
> 
> Using find in a list context is not correct.
> 
> ------------------------------------------------------------------------
> *Van:* koha-devel-bounces at lists.koha-community.org
> <koha-devel-bounces at lists.koha-community.org> namens Julian Maurice
> <julian.maurice at biblibre.com>
> *Verzonden:* woensdag 13 december 2017 14:34:07
> *Aan:* koha-devel at lists.koha-community.org
> *Onderwerp:* [Koha-devel] Bug 18539 - Forbid Koha::Objects->find calls
> in list context
>  
> Hi developers,
> 
> I stumbled upon a line of code recently and I can't figure out why it
> has be done this way. I hope you can help me :)
> 
> The line in question is in Koha::Objects::find:
> 
>     croak 'Cannot use "->find" in list context' if wantarray;
> 
> I read the two bugs (18539 and 18179) and the link given by Jonathan but
> I still don't understand why the call in list context has been
> forbidden. Why not simply return undef (an explicit undef) when no
> records have be found ? It would work as expected in scalar and list
> contexts.
> 
> Here is a possible rewrite of 'find' to better explain what I mean:
> 
>     sub find {
>         my ( $self, @pars ) = @_;
> 
>         my $object = undef;
> 
>         @pars = grep { defined } @pars;
>         if (@pars) {
>             my $result = $self->_resultset()->find(@pars);
>             if ($result) {
>                 $object = $self->object_class()->_new_from_dbic($result);
>             }
>         }
> 
>         return $object;
>     }
> 
> @a = Koha::Patrons->find('foo'); # would result in @a = (undef)
> {a => K::P->find('foo'), b => 'bar'}; # would result in {a => undef, b
> => 'bar'}
> 
> Please tell me what you think.
> 
> -- 
> Julian Maurice <julian.maurice at biblibre.com>
> BibLibre
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-- 
Julian Maurice <julian.maurice at biblibre.com>
BibLibre