Merge 'trunk' into 'sybase'
[dbsrgits/DBIx-Class.git] / lib / DBIx / Class / Relationship / BelongsTo.pm
CommitLineData
9b83fccd 1package # hide from PAUSE
2 DBIx::Class::Relationship::BelongsTo;
3
4# Documentation for these methods can be found in
5# DBIx::Class::Relationship
07037f89 6
7use strict;
8use warnings;
9
044e70c7 10our %_pod_inherit_config =
11 (
12 class_map => { 'DBIx::Class::Relationship::BelongsTo' => 'DBIx::Class::Relationship' }
13 );
14
07037f89 15sub belongs_to {
16 my ($class, $rel, $f_class, $cond, $attrs) = @_;
6bf6ba2f 17
18 # assume a foreign key contraint unless defined otherwise
19 $attrs->{is_foreign_key_constraint} = 1
20 if not exists $attrs->{is_foreign_key_constraint};
cef1bdda 21 $attrs->{undef_on_null_fk} = 1
22 if not exists $attrs->{undef_on_null_fk};
6bf6ba2f 23
aeb1bf75 24 # no join condition or just a column name
7b601771 25 if (!ref $cond) {
fd4df975 26 $class->ensure_class_loaded($f_class);
aeb1bf75 27 my %f_primaries = map { $_ => 1 } eval { $f_class->primary_columns };
fd4df975 28 $class->throw_exception(
29 "Can't infer join condition for ${rel} on ${class}; ".
30 "unable to load ${f_class}: $@"
31 ) if $@;
1e3bc087 32
33 my ($pri, $too_many) = keys %f_primaries;
fd4df975 34 $class->throw_exception(
35 "Can't infer join condition for ${rel} on ${class}; ".
36 "${f_class} has no primary keys"
37 ) unless defined $pri;
38 $class->throw_exception(
39 "Can't infer join condition for ${rel} on ${class}; ".
40 "${f_class} has multiple primary keys"
41 ) if $too_many;
1e3bc087 42
43 my $fk = defined $cond ? $cond : $rel;
fd4df975 44 $class->throw_exception(
45 "Can't infer join condition for ${rel} on ${class}; ".
46 "$fk is not a column of $class"
47 ) unless $class->has_column($fk);
1e3bc087 48
49 my $acc_type = $class->has_column($rel) ? 'filter' : 'single';
07037f89 50 $class->add_relationship($rel, $f_class,
1e3bc087 51 { "foreign.${pri}" => "self.${fk}" },
5a3c5f64 52 { accessor => $acc_type, %{$attrs || {}} }
07037f89 53 );
54 }
aeb1bf75 55 # explicit join condition
4ff1b819 56 elsif (ref $cond) {
57 if (ref $cond eq 'HASH') { # ARRAY is also valid
58 my $cond_rel;
59 for (keys %$cond) {
60 if (m/\./) { # Explicit join condition
61 $cond_rel = $cond;
62 last;
63 }
64 $cond_rel->{"foreign.$_"} = "self.".$cond->{$_};
99be059e 65 }
4ff1b819 66 $cond = $cond_rel;
07037f89 67 }
4ff1b819 68 my $acc_type = ((ref $cond eq 'HASH')
69 && keys %$cond == 1
70 && $class->has_column($rel))
71 ? 'filter'
72 : 'single';
07037f89 73 $class->add_relationship($rel, $f_class,
4ff1b819 74 $cond,
0cc03829 75 { accessor => $acc_type, %{$attrs || {}} }
07037f89 76 );
77 }
7b601771 78 else {
fd4df975 79 $class->throw_exception(
80 'third argument for belongs_to must be undef, a column name, '.
81 'or a join condition'
82 );
7b601771 83 }
07037f89 84 return 1;
85}
86
e09b8a14 87# Attempt to remove the POD so it (maybe) falls off the indexer
503536d5 88
e09b8a14 89#=head1 AUTHORS
90#
91#Alexander Hartmaier <Alexander.Hartmaier@t-systems.at>
92#
93#Matt S. Trout <mst@shadowcatsystems.co.uk>
94#
95#=cut
503536d5 96
07037f89 971;