1package # hide from PAUSE
2    DBIx::Class::Relationship::HasOne;
3
4use strict;
5use warnings;
6use Carp::Clan qw/^DBIx::Class/;
7
8our %_pod_inherit_config =
9  (
10   class_map => { 'DBIx::Class::Relationship::HasOne' => 'DBIx::Class::Relationship' }
11  );
12
13sub might_have {
14  shift->_has_one('LEFT' => @_);
15}
16
17sub has_one {
18  shift->_has_one(undef() => @_);
19}
20
21sub _has_one {
22  my ($class, $join_type, $rel, $f_class, $cond, $attrs) = @_;
23  unless (ref $cond) {
24    $class->ensure_class_loaded($f_class);
25
26    my $pri = $class->_get_primary_key;
27
28    $class->throw_exception(
29      "might_have/has_one needs a primary key  to infer a join; ".
30      "${class} has none"
31    ) if !defined $pri && (!defined $cond || !length $cond);
32
33    my $f_class_loaded = eval { $f_class->columns };
34    my ($f_key,$too_many,$guess);
35    if (defined $cond && length $cond) {
36      $f_key = $cond;
37      $guess = "caller specified foreign key '$f_key'";
38    } elsif ($f_class_loaded && $f_class->has_column($rel)) {
39      $f_key = $rel;
40      $guess = "using given relationship '$rel' for foreign key";
41    } else {
42      $f_key = $class->_get_primary_key($f_class);
43      $guess = "using primary key of foreign class for foreign key";
44    }
45    $class->throw_exception(
46      "No such column ${f_key} on foreign class ${f_class} ($guess)"
47    ) if $f_class_loaded && !$f_class->has_column($f_key);
48    $cond = { "foreign.${f_key}" => "self.${pri}" };
49  }
50  $class->_validate_cond($cond);
51  $class->add_relationship($rel, $f_class,
52   $cond,
53   { accessor => 'single',
54     cascade_update => 1, cascade_delete => 1,
55     ($join_type ? ('join_type' => $join_type) : ()),
56     %{$attrs || {}} });
57  1;
58}
59
60sub _get_primary_key {
61  my ( $class, $target_class ) = @_;
62  $target_class ||= $class;
63  my ($pri, $too_many) = eval { $target_class->_pri_cols };
64  $class->throw_exception(
65    "Can't infer join condition on ${target_class}: $@"
66  ) if $@;
67
68  $class->throw_exception(
69    "might_have/has_one can only infer join for a single primary key; ".
70    "${class} has more"
71  ) if $too_many;
72  return $pri;
73}
74
75sub _validate_cond {
76  my ($class, $cond )  = @_;
77
78  return if $ENV{DBIC_DONT_VALIDATE_RELS};
79  return unless 'HASH' eq ref $cond;
80  foreach my $foreign_id ( keys %$cond ) {
81    my $self_id = $cond->{$foreign_id};
82
83    # we can ignore a bad $self_id because add_relationship handles this
84    # warning
85    return unless $self_id =~ /^self\.(.*)$/;
86    my $key = $1;
87    my $column_info = $class->column_info($key);
88    if ( $column_info->{is_nullable} ) {
89      carp(qq'"might_have/has_one" must not be on columns with is_nullable set to true ($class/$key). This might indicate an incorrect use of those relationship helpers instead of belongs_to.');
90    }
91  }
92}
93
941;
95