RE: No way to instantiate two related CDBI classes at once, isthere?

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I'm not so bothered about avoiding the need to create an accessor; the
method which creates both objects will sit outside either.

But I can't get it to work.

I've tried calling $class->sth_to_objects($sth) or $class->construct
repeatedly for each class, and although the first resulting object is
fine, the second doesn't contain all the fields from the initiating hash
- least of all its primary key. There's a large chance that I'm missing
something, but it looks to me that something's going wrong inside
Class::DBI::_init.

It seems to be pulling a broken something out of Live_Objects. Despite
the fact that there's nothing in Live_Objects. From the Perl debugger:

526:            unless (defined($obj =3D $Live_Objects{$obj_key})) {
  DB<5> p $obj_key
Conquer::Persist::ActiveRecord::PC|cha_id=3D55

  DB<7> p %Live_Objects

  DB<11> p Dumper(%Class::DBI::Live_Objects)

  DB<12> p $Live_Objects{$obj_key}
Use of uninitialized value in print at (eval
83)[/usr/local/perl-5.6.1/lib/perl5/5.6.1/perl5db.pl:1521] line 2.

  DB<13> p $obj
Use of uninitialized value in print at (eval
84)[/usr/local/perl-5.6.1/lib/perl5/5.6.1/perl5db.pl:1521] line 2.

  DB<14> p $obj =3D $Live_Objects{$obj_key}
Use of uninitialized value in print at (eval
85)[/usr/local/perl-5.6.1/lib/perl5/5.6.1/perl5db.pl:1521] line 2.

  DB<15> p defined($obj =3D $Live_Objects{$obj_key})

  DB<16> p $obj
Use of uninitialized value in print at (eval
87)[/usr/local/perl-5.6.1/lib/perl5/5.6.1/perl5db.pl:1521] line 2.

  DB<17> s
Class::DBI::_init(/home/ianm/conquer/cgi-bin/lib/Class/DBI.pm:542):
542:            return $obj;
  DB<17> p $obj
Conquer::Persist::ActiveRecord::PC
  DB<18> p Dumper($obj)
$VAR1 =3D bless( {
                 'sso_user_id' =3D> undef,
			... (partial list of fields, none of which have
true values, deleted)
               }, 'Conquer::Persist::ActiveRecord::PC' );

  DB<19>=20

-----Original Message-----
From: Perrin Harkins [mailto:perrin@xxxx.xxx]=20
Sent: 09 August 2004 16:56
To: brano@xxxxxxxxxx.xx
Cc: cdbi-talk@xxxxxx.xxxxx.xxx
Subject: Re: No way to instantiate two related CDBI classes at once,
isthere?


It can be done.

package Foo;

__PACKAGE__->set_sql(get_both =3D> qq{
    SELECT foo.id, foo.other, bar.id, bar.other
    FROM __TABLE__
    WHERE foo.a =3D ?
};

sub retrieve_with_bar {
    my ($class, $id) =3D @_;
    my $sth =3D $class->sq_get_both();
    $sth->execute($id);
    my $row =3D $sth->fetchrow_arrayref();
    my $foo =3D Foo->construct($row->[0,1]);
    my $bar =3D Bar->construct($row->[2,3]);
    $foo->{'_bar_object'} =3D $bar;
    return $foo;
}

sub bar {
    my $self =3D shift;
    return $self->{'_bar_object'};
}

If you read through the Class::DBI::Relationship::MightHave source, you
can see how to make it store the object just like the normal might_have
method does, and avoid the need to create your own accessor.  That would
certainly violate encapsulation, and my example here has
retrieve_with_bar tightly coupled to the SQL statement, but it should
work.

- Perrin


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