package # hide from PAUSE
DBIx::Class::Relationship::BelongsTo;
# Documentation for these methods can be found in
# DBIx::Class::Relationship
use strict;
use warnings;
use Try::Tiny;
use namespace::clean;
our %_pod_inherit_config =
(
class_map => { 'DBIx::Class::Relationship::BelongsTo' => 'DBIx::Class::Relationship' }
);
sub belongs_to {
my ($class, $rel, $f_class, $cond, $attrs) = @_;
# assume a foreign key contraint unless defined otherwise
$attrs->{is_foreign_key_constraint} = 1
if not exists $attrs->{is_foreign_key_constraint};
$attrs->{undef_on_null_fk} = 1
if not exists $attrs->{undef_on_null_fk};
# no join condition or just a column name
if (!ref $cond) {
$class->ensure_class_loaded($f_class);
my %f_primaries = map { $_ => 1 } try { $f_class->_pri_cols }
catch {
$class->throw_exception( "Can't infer join condition for '$rel' on ${class}: $_");
};
my ($pri, $too_many) = keys %f_primaries;
$class->throw_exception(
"Can't infer join condition for '$rel' on ${class}: "
. "${f_class} has multiple primary keys"
) if $too_many;
my $fk = defined $cond ? $cond : $rel;
$class->throw_exception(
"Can't infer join condition for '$rel' on ${class}: "
. "'$fk' is not a column of $class"
) unless $class->has_column($fk);
$cond = { "foreign.${pri}" => "self.${fk}" };
}
# explicit join condition
elsif (ref $cond) {
if (ref $cond eq 'HASH') { # ARRAY is also valid
my $cond_rel;
for (keys %$cond) {
if (m/\./) { # Explicit join condition
$cond_rel = $cond;
last;
}
$cond_rel->{"foreign.$_"} = "self.".$cond->{$_};
}
$cond = $cond_rel;
}
}
# dunno
else {
$class->throw_exception(
'third argument for belongs_to must be undef, a column name, '.
'or a join condition'
);
}
my $acc_type = (
ref $cond eq 'HASH'
and
keys %$cond == 1
and
$class->has_column($rel)
) ? 'filter' : 'single';
my $fk_columns = ($acc_type eq 'single' and ref $cond eq 'HASH')
? { map { $_ =~ /^self\.(.+)/ ? ( $1 => 1 ) : () } (values %$cond ) }
: undef
;
$class->add_relationship($rel, $f_class,
$cond,
{
accessor => $acc_type,
$fk_columns ? ( fk_columns => $fk_columns ) : (),
%{$attrs || {}}
}
);
return 1;
}
# Attempt to remove the POD so it (maybe) falls off the indexer
#=head1 AUTHORS
#
#Alexander Hartmaier <Alexander.Hartmaier@t-systems.at>
#
#Matt S. Trout <mst@shadowcatsystems.co.uk>
#
#=cut
1;