X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FRelationship%2FBelongsTo.pm;h=b871266500d85be05a6afdf18a8991d1d47ce66c;hb=a28009914a3e447af53737d503b1953160d146c9;hp=f59f5324b65d8639b675995ec452081875a2edb2;hpb=1240ad98aef51c2b33675451b5dc7a7973fe26d6;p=dbsrgits%2FDBIx-Class-Historic.git

diff --git a/lib/DBIx/Class/Relationship/BelongsTo.pm b/lib/DBIx/Class/Relationship/BelongsTo.pm
index f59f532..b871266 100644
--- a/lib/DBIx/Class/Relationship/BelongsTo.pm
+++ b/lib/DBIx/Class/Relationship/BelongsTo.pm
@@ -1,32 +1,47 @@
-package DBIx::Class::Relationship::BelongsTo;
+package # hide from PAUSE
+    DBIx::Class::Relationship::BelongsTo;
+
+# Documentation for these methods can be found in
+# DBIx::Class::Relationship
 
 use strict;
 use warnings;
 
 sub belongs_to {
   my ($class, $rel, $f_class, $cond, $attrs) = @_;
-  eval "require $f_class";
-  if ($@) {
-    $class->throw($@) unless $@ =~ /Can't locate/;
-  }
+  # no join condition or just a column name
+  if (!ref $cond) {
+    $class->ensure_class_loaded($f_class);
+    my %f_primaries = map { $_ => 1 } eval { $f_class->primary_columns };
+    $class->throw_exception(
+      "Can't infer join condition for ${rel} on ${class}; ".
+      "unable to load ${f_class}: $@"
+    ) if $@;
 
-  my %f_primaries;
-  $f_primaries{$_} = 1 for eval { $f_class->primary_columns };
-  my $f_loaded = !$@;
-  # single key relationship
-  if (not defined $cond) {
-    $class->throw("Can't infer join condition for ${rel} on ${class}; unable to load ${f_class}") unless $f_loaded;
     my ($pri, $too_many) = keys %f_primaries;
-    $class->throw("Can't infer join condition for ${rel} on ${class}; ${f_class} has multiple primary key") if $too_many;
-    $class->throw("Can't find any primary keys for $f_class, try adding some") if !$pri;
-    my $acc_type = ($class->has_column($rel)) ? 'filter' : 'single';
+    $class->throw_exception(
+      "Can't infer join condition for ${rel} on ${class}; ".
+      "${f_class} has no primary keys"
+    ) unless defined $pri;
+    $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);
+
+    my $acc_type = $class->has_column($rel) ? 'filter' : 'single';
     $class->add_relationship($rel, $f_class,
-      { "foreign.${pri}" => "self.${rel}" },
+      { "foreign.${pri}" => "self.${fk}" },
       { accessor => $acc_type, %{$attrs || {}} }
     );
   }
-  # multiple key relationship
-  else {
+  # explicit join condition
+  elsif (ref $cond eq 'HASH') {
     my $cond_rel;
     for (keys %$cond) {
       if (m/\./) { # Explicit join condition
@@ -35,9 +50,18 @@ sub belongs_to {
       }
       $cond_rel->{"foreign.$_"} = "self.".$cond->{$_};
     }
+    my $acc_type = (keys %$cond_rel == 1 and $class->has_column($rel))
+      ? 'filter'
+      : 'single';
     $class->add_relationship($rel, $f_class,
       $cond_rel,
-      { accessor => 'single', %{$attrs || {}} }
+      { accessor => $acc_type, %{$attrs || {}} }
+    );
+  }
+  else {
+    $class->throw_exception(
+      'third argument for belongs_to must be undef, a column name, '.
+      'or a join condition'
     );
   }
   return 1;