do not use "me" on the related_resultset pessimization

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

diff --git a/lib/DBIx/Class/Relationship/Base.pm b/lib/DBIx/Class/Relationship/Base.pm
index 1a46d4e..050c056 100644 (file)
--- a/lib/DBIx/Class/Relationship/Base.pm
+++ b/lib/DBIx/Class/Relationship/Base.pm
@@ -447,57 +447,58 @@ sub related_resultset {
       }
     }
 
-    # this is where we're going to check if we have an extended
-    # rel. In that case, we need to: 1) If there's a second
-    # condition, we use that instead.  2) If there is only one
-    # condition, we need to join the current resultsource and have
-    # additional conditions.
-    if (ref $rel_info->{cond} eq 'CODE') {
-      # this is an extended relationship.
-      if ($extended_cond) {
+    if (ref $rel_info->{cond} eq 'CODE' && !$extended_cond) {
+      # since we don't have the extended condition, we need to step
+      # back, get a resultset for the current row and do a
+      # search_related there.
+
+      my $row_srcname = $source->source_name;
+      my $base_rs_class = $source->resultset_class;
+      my $base_rs_attr  = $source->resultset_attributes;
+      my $base_rs = $base_rs_class->new
+        ($source,
+         {
+          %$base_rs_attr,
+          alias => $source->storage->relname_to_table_alias(lc($row_srcname).'__row',1)
+         });
+      my $alias = $base_rs->current_source_alias;
+      my %identity = map { ( "${alias}.${_}" => $self->get_column($_) ) } $source->primary_columns;
+      my $row_rs = $base_rs->search(\%identity);
+      my $related = $row_rs->related_resultset($rel, { %$attrs, alias => 'me' });
+      $related->search($query);
+
+    } else {
+      # when we have the extended condition or we have a simple
+      # relationship declaration, it can optimize the JOIN away by
+      # simply adding the identity in WHERE.
+
+      if (ref $rel_info->{cond} eq 'CODE' && $extended_cond) {
         $cond = $extended_cond;
-
-      } else {
-
-        # it's a bit hard to find out what to do with other joins
-        $self->throw_exception('Extended relationship '.$rel.' with additional join requires optimized declaration')
-          if exists $attrs->{join} && $attrs->{join};
-
-        # aliases get a bit more complicated, so we won't accept additional queries
-        $self->throw_exception('Extended relationship '.$rel.' with additional query requires optimized declaration')
-          if $query;
-
-        $attrs->{from} =
-          [ { $rel => $self->result_source->from },
-            [ { 'me' => $self->result_source->related_source($rel)->from }, { 1 => 1 } ] ];
-
-        $cond->{"${rel}.${_}"} = $self->get_column($_) for $self->result_source->primary_columns;
       }
-    }
 
-    if (ref $cond eq 'ARRAY') {
-      $cond = [ map {
-        if (ref $_ eq 'HASH') {
-          my $hash;
-          foreach my $key (keys %$_) {
-            my $newkey = $key !~ /\./ ? "me.$key" : $key;
-            $hash->{$newkey} = $_->{$key};
+      if (ref $cond eq 'ARRAY') {
+        $cond = [ map {
+          if (ref $_ eq 'HASH') {
+            my $hash;
+            foreach my $key (keys %$_) {
+              my $newkey = $key !~ /\./ ? "me.$key" : $key;
+              $hash->{$newkey} = $_->{$key};
+            }
+            $hash;
+          } else {
+            $_;
           }
-          $hash;
-        } else {
-          $_;
+        } @$cond ];
+      } elsif (ref $cond eq 'HASH') {
+        foreach my $key (grep { ! /\./ } keys %$cond) {
+          $cond->{"me.$key"} = delete $cond->{$key};
         }
-      } @$cond ];
-    } elsif (ref $cond eq 'HASH') {
-      foreach my $key (grep { ! /\./ } keys %$cond) {
-        $cond->{"me.$key"} = delete $cond->{$key};
       }
-    }
 
-    $query = ($query ? { '-and' => [ $cond, $query ] } : $cond);
-    $self->result_source->related_source($rel)->resultset->search(
-      $query, $attrs
-    );
+      $query = ($query ? { '-and' => [ $cond, $query ] } : $cond);
+      $self->result_source->related_source($rel)->resultset->search(
+        $query, $attrs);
+    }
   };
 }
 
@@ -576,6 +577,37 @@ in L<DBIx::Class::ResultSet> for details.
 sub create_related {
   my $self = shift;
   my $rel = shift;
+
+  $self->throw_exception("Can't call *_related as class methods")
+    unless ref $self;
+
+  # we need to stop and check if this is at all possible. If this is
+  # an extended relationship with an incomplete definition, we should
+  # just forbid it right now.
+  my $rel_info = $self->result_source->relationship_info($rel);
+  if (ref $rel_info->{cond} eq 'CODE') {
+    my ($cond, $ext) = $rel_info->{cond}->({ self_alias => 'me',
+                                             foreign_alias => $rel,
+                                             self_rowobj => $self
+                                           });
+    $self->throw_exception("unable to set_from_related - no simplified condition available for '${rel}'")
+      unless $ext;
+
+    # now we need to make sure all non-identity relationship
+    # definitions are overriden.
+    my ($argref) = @_;
+    while ( my($col, $value) = each %$ext ) {
+      $col =~ s/^$rel\.//;
+      my $vref = ref $value;
+      if ($vref eq 'HASH') {
+        if (keys(%$value) && (keys %$value)[0] ne '=' &&
+            !exists $argref->{$col}) {
+          $self->throw_exception("unable to set_from_related via complex '${rel}' condition on column(s): '${col}'")
+        }
+      }
+    }
+  }
+
   my $obj = $self->search_related($rel)->create(@_);
   delete $self->{related_resultsets}->{$rel};
   return $obj;