X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FResultSetColumn.pm;h=7b0fee6db81ba23449c51ebdcc9cfc00bf3c2178;hb=152002c48f71b635f56c2a1709581a6f7e5e6650;hp=68cc4e0c795f8c765a5e9135da4ef67c7e2bd347;hpb=78bf8b8b0f821581b58225e4cbb5595df3ff2c21;p=dbsrgits%2FDBIx-Class.git

diff --git a/lib/DBIx/Class/ResultSetColumn.pm b/lib/DBIx/Class/ResultSetColumn.pm
index 68cc4e0..7b0fee6 100644
--- a/lib/DBIx/Class/ResultSetColumn.pm
+++ b/lib/DBIx/Class/ResultSetColumn.pm
@@ -2,6 +2,7 @@ package DBIx::Class::ResultSetColumn;
 use strict;
 use warnings;
 use base 'DBIx::Class';
+use List::Util;
 
 =head1 NAME
 
@@ -36,8 +37,19 @@ sub new {
   my ($class, $rs, $column) = @_;
   $class = ref $class if ref $class;
   my $new_parent_rs = $rs->search_rs; # we don't want to mess up the original, so clone it
-  $new_parent_rs->{attrs}->{prefetch} = undef; # prefetch causes additional columns to be fetched
-  my $new = bless { _column => $column, _parent_resultset => $new_parent_rs }, $class;
+  my $attrs = $new_parent_rs->_resolved_attrs;
+  $new_parent_rs->{attrs}->{$_} = undef for qw(prefetch include_columns +select +as); # prefetch, include_columns, +select, +as cause additional columns to be fetched
+
+  # 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
+  # definition set up with 'select' or '+select' attrs), otherwise use $column
+  # (to create a new column definition on-the-fly).
+  my $as_list = $attrs->{as} || [];
+  my $select_list = $attrs->{select} || [];
+  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 = bless { _select => $select, _as => $column, _parent_resultset => $new_parent_rs }, $class;
   $new->throw_exception("column must be supplied") unless $column;
   return $new;
 }
@@ -62,8 +74,7 @@ one value.
 
 sub next {
   my $self = shift;
-  $self->{_resultset} = $self->{_parent_resultset}->search(undef, {select => [$self->{_column}], as => [$self->{_column}]}) unless ($self->{_resultset});
-  my ($row) = $self->{_resultset}->cursor->next;
+  my ($row) = $self->_resultset->cursor->next;
   return $row;
 }
 
@@ -87,7 +98,53 @@ than row objects.
 
 sub all {
   my $self = shift;
-  return map {$_->[0]} $self->{_parent_resultset}->search(undef, {select => [$self->{_column}], as => [$self->{_column}]})->cursor->all;
+  return map { $_->[0] } $self->_resultset->cursor->all;
+}
+
+=head2 reset
+
+=over 4
+
+=item Arguments: none
+
+=item Return Value: $self
+
+=back
+
+Resets the underlying resultset's cursor, so you can iterate through the
+elements of the column again.
+
+Much like L<DBIx::Class::ResultSet/reset>.
+
+=cut
+
+sub reset {
+  my $self = shift;
+  $self->_resultset->cursor->reset;
+  return $self;
+}
+
+=head2 first
+
+=over 4
+
+=item Arguments: none
+
+=item Return Value: $value
+
+=back
+
+Resets the underlying resultset and returns the next value of the column in the
+resultset (or C<undef> if there is none).
+
+Much like L<DBIx::Class::ResultSet/first> but just returning the one value.
+
+=cut
+
+sub first {
+  my $self = shift;
+  my ($row) = $self->_resultset->cursor->reset->next;
+  return $row;
 }
 
 =head2 min
@@ -175,7 +232,7 @@ value. Produces the following SQL:
 
 sub func {
   my ($self,$function) = @_;
-  my $cursor = $self->{_parent_resultset}->search(undef, {select => {$function => $self->{_column}}, as => [$self->{_column}]})->cursor;
+  my $cursor = $self->{_parent_resultset}->search(undef, {select => {$function => $self->{_select}}, as => [$self->{_as}]})->cursor;
   
   if( wantarray ) {
     return map { $_->[ 0 ] } $cursor->all;
@@ -184,6 +241,44 @@ sub func {
   return ( $cursor->next )[ 0 ];
 }
 
+=head2 throw_exception
+
+See L<DBIx::Class::Schema/throw_exception> for details.
+  
+=cut 
+    
+sub throw_exception {
+  my $self=shift;
+  if (ref $self && $self->{_parent_resultset}) {
+    $self->{_parent_resultset}->throw_exception(@_)
+  } else {
+    croak(@_);
+  }
+}
+
+# _resultset
+#
+# Arguments: none
+#
+# Return Value: $resultset
+#
+#  $year_col->_resultset->next
+#
+# Returns the underlying resultset. Creates it from the parent resultset if
+# necessary.
+# 
+sub _resultset {
+  my $self = shift;
+
+  return $self->{_resultset} ||= $self->{_parent_resultset}->search(undef,
+    {
+      select => [$self->{_select}],
+      as => [$self->{_as}]
+    }
+  );
+}
+
+
 1;
 
 =head1 AUTHORS