Trailing WS crusade - got to save them bits

[dbsrgits/DBIx-Class.git] / lib / DBIx / Class / ResultSetColumn.pm

diff --git a/lib/DBIx/Class/ResultSetColumn.pm b/lib/DBIx/Class/ResultSetColumn.pm
index 14b35f7..49adce9 100644 (file)
--- a/lib/DBIx/Class/ResultSetColumn.pm
+++ b/lib/DBIx/Class/ResultSetColumn.pm
@@ -4,10 +4,11 @@ use strict;
 use warnings;
 
 use base 'DBIx::Class';
-
-use Carp::Clan qw/^DBIx::Class/;
+use DBIx::Class::Carp;
 use DBIx::Class::Exception;
-use List::Util;
+
+# not importing first() as it will clash with our own method
+use List::Util ();
 
 =head1 NAME
 
@@ -45,18 +46,7 @@ sub new {
   $rs->throw_exception('column must be supplied') unless $column;
 
   my $orig_attrs = $rs->_resolved_attrs;
-  my $new_parent_rs = $rs->search_rs;
-  my $new_attrs = $new_parent_rs->{attrs} ||= {};
-
-  # since what we do is actually chain to the original resultset, we need to throw
-  # away all selectors (otherwise they'll chain)
-  delete $new_attrs->{$_} for (qw/columns +columns select +select as +as cols include_columns/);
-
-  # prefetch causes additional columns to be fetched, but we can not just make a new
-  # rs via the _resolved_attrs trick - we need to retain the separation between
-  # +select/+as and select/as. At the same time we want to preserve any joins that the
-  # prefetch would otherwise generate.
-  $new_attrs->{join} = $rs->_merge_attr( delete $new_attrs->{join}, delete $new_attrs->{prefetch} );
+  my $alias = $rs->current_source_alias;
 
   # If $column can be found in the 'as' list of the parent resultset, use the
   # corresponding element of its 'select' list (to keep any custom column
@@ -67,9 +57,37 @@ sub new {
   my $as_index = List::Util::first { ($as_list->[$_] || "") eq $column } 0..$#$as_list;
   my $select = defined $as_index ? $select_list->[$as_index] : $column;
 
+  my $new_parent_rs;
+  # analyze the order_by, and see if it is done over a function/nonexistentcolumn
+  # if this is the case we will need to wrap a subquery since the result of RSC
+  # *must* be a single column select
+  my %collist = map
+    { $_ => 1, ($_ =~ /\./) ? () : ( "$alias.$_" => 1 ) }
+    ($rs->result_source->columns, $column)
+  ;
+  if (
+    scalar grep
+      { ! $collist{$_->[0]} }
+      ( $rs->result_source->schema->storage->_extract_order_criteria ($orig_attrs->{order_by} ) )
+  ) {
+    # nuke the prefetch before collapsing to sql
+    my $subq_rs = $rs->search;
+    $subq_rs->{attrs}{join} = $subq_rs->_merge_joinpref_attr( $subq_rs->{attrs}{join}, delete $subq_rs->{attrs}{prefetch} );
+    $new_parent_rs = $subq_rs->as_subselect_rs;
+  }
+
+  $new_parent_rs ||= $rs->search_rs;
+  my $new_attrs = $new_parent_rs->{attrs} ||= {};
+
+  # prefetch causes additional columns to be fetched, but we can not just make a new
+  # rs via the _resolved_attrs trick - we need to retain the separation between
+  # +select/+as and select/as. At the same time we want to preserve any joins that the
+  # prefetch would otherwise generate.
+  $new_attrs->{join} = $rs->_merge_joinpref_attr( $new_attrs->{join}, delete $new_attrs->{prefetch} );
+
   # {collapse} would mean a has_many join was injected, which in turn means
   # we need to group *IF WE CAN* (only if the column in question is unique)
-  if (!$new_attrs->{group_by} && keys %{$orig_attrs->{collapse}}) {
+  if (!$orig_attrs->{group_by} && keys %{$orig_attrs->{collapse}}) {
 
     # scan for a constraint that would contain our column only - that'd be proof
     # enough it is unique
@@ -131,7 +149,7 @@ sub as_query { return shift->_resultset->as_query(@_) }
 Returns the next value of the column in the resultset (or C<undef> if
 there is none).
 
-Much like L<DBIx::Class::ResultSet/next> but just returning the 
+Much like L<DBIx::Class::ResultSet/next> but just returning the
 one value.
 
 =cut
@@ -423,7 +441,7 @@ sub func_rs {
 
 See L<DBIx::Class::Schema/throw_exception> for details.
 
-=cut 
+=cut
 
 sub throw_exception {
   my $self=shift;