release 0.08123

[dbsrgits/DBIx-Class.git] / lib / DBIx / Class / Relationship / HasOne.pm

diff --git a/lib/DBIx/Class/Relationship/HasOne.pm b/lib/DBIx/Class/Relationship/HasOne.pm
index 584ed2a..3f1160d 100644 (file)
--- a/lib/DBIx/Class/Relationship/HasOne.pm
+++ b/lib/DBIx/Class/Relationship/HasOne.pm
@@ -1,35 +1,55 @@
-package DBIx::Class::Relationship::HasOne;
+package # hide from PAUSE
+    DBIx::Class::Relationship::HasOne;
 
 use strict;
 use warnings;
+use Carp::Clan qw/^DBIx::Class/;
+use Try::Tiny;
+use namespace::clean;
+
+our %_pod_inherit_config =
+  (
+   class_map => { 'DBIx::Class::Relationship::HasOne' => 'DBIx::Class::Relationship' }
+  );
 
 sub might_have {
   shift->_has_one('LEFT' => @_);
 }
 
 sub has_one {
-  shift->_has_one(undef => @_);
+  shift->_has_one(undef() => @_);
 }
 
 sub _has_one {
   my ($class, $join_type, $rel, $f_class, $cond, $attrs) = @_;
-  eval "require $f_class";
   unless (ref $cond) {
-    my ($pri, $too_many) = keys %{ $class->_primaries };
-    $class->throw( "might_have/has_one can only infer join for a single primary key; ${class} has more" )
-      if $too_many;
-    my $f_key;
-    if ($cond) {
+    $class->ensure_class_loaded($f_class);
+
+    my $pri = $class->_get_primary_key;
+
+    $class->throw_exception(
+      "might_have/has_one needs a primary key  to infer a join; ".
+      "${class} has none"
+    ) if !defined $pri && (!defined $cond || !length $cond);
+
+    my $f_class_loaded = try { $f_class->columns };
+    my ($f_key,$too_many,$guess);
+    if (defined $cond && length $cond) {
       $f_key = $cond;
-    } elsif ($f_class->_columns->{$rel}) {
+      $guess = "caller specified foreign key '$f_key'";
+    } elsif ($f_class_loaded && $f_class->has_column($rel)) {
       $f_key = $rel;
+      $guess = "using given relationship '$rel' for foreign key";
     } else {
-      ($f_key, $too_many) = keys %{ $f_class->_primaries };
-      $class->throw( "might_have/has_one can only infer join for a single primary key; ${f_class} has more" )
-        if $too_many;
+      $f_key = $class->_get_primary_key($f_class);
+      $guess = "using primary key of foreign class for foreign key";
     }
+    $class->throw_exception(
+      "No such column ${f_key} on foreign class ${f_class} ($guess)"
+    ) if $f_class_loaded && !$f_class->has_column($f_key);
     $cond = { "foreign.${f_key}" => "self.${pri}" };
   }
+  $class->_validate_has_one_condition($cond);
   $class->add_relationship($rel, $f_class,
    $cond,
    { accessor => 'single',
@@ -39,4 +59,40 @@ sub _has_one {
   1;
 }
 
+sub _get_primary_key {
+  my ( $class, $target_class ) = @_;
+  $target_class ||= $class;
+  my ($pri, $too_many) = try { $target_class->_pri_cols }
+    catch {
+      $class->throw_exception("Can't infer join condition on ${target_class}: $_");
+    };
+
+  $class->throw_exception(
+    "might_have/has_one can only infer join for a single primary key; ".
+    "${class} has more"
+  ) if $too_many;
+  return $pri;
+}
+
+sub _validate_has_one_condition {
+  my ($class, $cond )  = @_;
+
+  return if $ENV{DBIC_DONT_VALIDATE_RELS};
+  return unless 'HASH' eq ref $cond;
+  foreach my $foreign_id ( keys %$cond ) {
+    my $self_id = $cond->{$foreign_id};
+
+    # we can ignore a bad $self_id because add_relationship handles this
+    # warning
+    return unless $self_id =~ /^self\.(.*)$/;
+    my $key = $1;
+    $class->throw_exception("Defining rel on ${class} that includes ${key} but no such column defined here yet")
+        unless $class->has_column($key);
+    my $column_info = $class->column_info($key);
+    if ( $column_info->{is_nullable} ) {
+      carp(qq'"might_have/has_one" must not be on columns with is_nullable set to true ($class/$key). This might indicate an incorrect use of those relationship helpers instead of belongs_to.');
+    }
+  }
+}
+
 1;