use warnings;
use base qw( DBIx::Class );
-use List::Util 'first';
-use namespace::clean;
-
=head1 NAME
DBIx::Class::Ordered - Modify the position of objects in an ordered list.
=cut
-__PACKAGE__->mk_classdata( 'position_column' => 'position' );
+__PACKAGE__->mk_classaccessor( 'position_column' => 'position' );
=head2 grouping_column
=cut
-__PACKAGE__->mk_classdata( 'grouping_column' );
+__PACKAGE__->mk_group_accessors( inherited => 'grouping_column' );
=head2 null_position_value
=cut
-__PACKAGE__->mk_classdata( 'null_position_value' => 0 );
+__PACKAGE__->mk_classaccessor( 'null_position_value' => 0 );
=head2 siblings
group excluding the one you called it on.
The ordering is a backwards-compatibility artifact - if you need
-a resultset with no ordering applied use L</_siblings>
+a resultset with no ordering applied use C<_siblings>
=cut
sub siblings {
my $position_column = $self->position_column;
- if ($self->is_column_changed ($position_column) ) {
+ my $rsrc = $self->result_source;
+
+ my $is_txn;
+ if ($is_txn = $rsrc->schema->storage->transaction_depth) {
+ # Reload position state from storage
+ # The thinking here is that if we are in a transaction, it is
+ # *more likely* the object went out of sync due to resultset
+ # level shenanigans. Instead of always reloading (slow) - go
+ # ahead and hand-hold only in the case of higher layers
+ # requesting the safety of a txn
+
+ $self->store_column(
+ $position_column,
+ ( $rsrc->resultset
+ ->search($self->_storage_ident_condition, { rows => 1, columns => $position_column })
+ ->cursor
+ ->next
+ )[0] || $self->throw_exception(
+ sprintf "Unable to locate object '%s' in storage - object went ouf of sync...?",
+ $self->ID
+ ),
+ );
+ delete $self->{_dirty_columns}{$position_column};
+ }
+ elsif ($self->is_column_changed ($position_column) ) {
# something changed our position, we need to know where we
# used to be - use the stashed value
$self->store_column($position_column, delete $self->{_column_data_in_storage}{$position_column});
return 0;
}
- my $guard = $self->result_source->schema->txn_scope_guard;
+ my $guard = $is_txn ? undef : $rsrc->schema->txn_scope_guard;
my ($direction, @between);
if ( $from_position < $to_position ) {
my $new_pos_val = $self->_position_value ($to_position); # record this before the shift
# we need to null-position the moved row if the position column is part of a constraint
- if (grep { $_ eq $position_column } ( map { @$_ } (values %{{ $self->result_source->unique_constraints }} ) ) ) {
+ if (grep { $_ eq $position_column } ( map { @$_ } (values %{{ $rsrc->unique_constraints }} ) ) ) {
$self->_ordered_internal_update({ $position_column => $self->null_position_value });
}
$self->_shift_siblings ($direction, @between);
$self->_ordered_internal_update({ $position_column => $new_pos_val });
- $guard->commit;
+ $guard->commit if $guard;
return 1;
}
if (! keys %$changed_ordering_cols) {
return $self->next::method( undef, @_ );
}
- elsif (defined first { exists $changed_ordering_cols->{$_} } @group_columns ) {
+ elsif (grep { exists $changed_ordering_cols->{$_} } @group_columns ) {
$self->move_to_group(
# since the columns are already re-set the _grouping_clause is correct
# move_to_group() knows how to get the original storage values
# add the current position/group to the things we track old values for
sub _track_storage_value {
my ($self, $col) = @_;
- return $self->next::method($col) || defined first { $_ eq $col } ($self->position_column, $self->_grouping_columns);
+ return (
+ $self->next::method($col)
+ ||
+ grep { $_ eq $col } ($self->position_column, $self->_grouping_columns)
+ );
}
=head1 METHODS FOR EXTENDING ORDERED
=cut
-__PACKAGE__->mk_classdata( '_initial_position_value' => 1 );
+__PACKAGE__->mk_classaccessor( '_initial_position_value' => 1 );
=head2 _next_position_value
local $rsrc->schema->{_ORDERED_INTERNAL_UPDATE} = 1;
my @pcols = $rsrc->primary_columns;
if (
- first { $_ eq $position_column } ( map { @$_ } (values %{{ $rsrc->unique_constraints }} ) )
+ grep { $_ eq $position_column } ( map { @$_ } (values %{{ $rsrc->unique_constraints }} ) )
) {
- my $cursor = $shift_rs->search (
+ my $clean_rs = $rsrc->resultset;
+
+ for ( $shift_rs->search (
{}, { order_by => { "-$ord", $position_column }, select => [$position_column, @pcols] }
- )->cursor;
- my $rs = $rsrc->resultset;
-
- my @all_data = $cursor->all;
- while (my $data = shift @all_data) {
- my $pos = shift @$data;
- my $cond;
- for my $i (0.. $#pcols) {
- $cond->{$pcols[$i]} = $data->[$i];
- }
-
- $rs->find($cond)->update ({ $position_column => $pos + ( ($op eq '+') ? 1 : -1 ) });
+ )->cursor->all ) {
+ my $pos = shift @$_;
+ $clean_rs->find(@$_)->update ({ $position_column => $pos + ( ($op eq '+') ? 1 : -1 ) });
}
}
else {
=head2 Multiple Moves
-Be careful when issuing move_* methods to multiple objects. If
-you've pre-loaded the objects then when you move one of the objects
-the position of the other object will not reflect their new value
-until you reload them from the database - see
-L<DBIx::Class::Row/discard_changes>.
+If you have multiple same-group result objects already loaded from storage,
+you need to be careful when executing C<move_*> operations on them:
+without a L</position_column> reload the L</_position_value> of the
+"siblings" will be out of sync with the underlying storage.
-There are times when you will want to move objects as groups, such
-as changing the parent of several objects at once - this directly
-conflicts with this problem. One solution is for us to write a
-ResultSet class that supports a parent() method, for example. Another
-solution is to somehow automagically modify the objects that exist
-in the current object's result set to have the new position value.
+Starting from version C<0.082800> DBIC will implicitly perform such
+reloads when the C<move_*> happens as a part of a transaction
+(a good example of such situation is C<< $ordered_resultset->delete_all >>).
+
+If it is not possible for you to wrap the entire call-chain in a transaction,
+you will need to call L<DBIx::Class::Row/discard_changes> to get an object
+up-to-date before proceeding, otherwise undefined behavior will result.
=head2 Default Values
Using a database defined default_value on one of your group columns
could result in the position not being assigned correctly.
-=head1 AUTHOR
-
- Original code framework
- Aran Deltac <bluefeet@cpan.org>
-
- Constraints support and code generalisation
- Peter Rabbitson <ribasushi@cpan.org>
+=head1 FURTHER QUESTIONS?
-=head1 LICENSE
+Check the list of L<additional DBIC resources|DBIx::Class/GETTING HELP/SUPPORT>.
-You may distribute this code under the same terms as Perl itself.
+=head1 COPYRIGHT AND LICENSE
+This module is free software L<copyright|DBIx::Class/COPYRIGHT AND LICENSE>
+by the L<DBIx::Class (DBIC) authors|DBIx::Class/AUTHORS>. You can
+redistribute it and/or modify it under the same terms as the
+L<DBIx::Class library|DBIx::Class/COPYRIGHT AND LICENSE>.
projects / dbsrgits/DBIx-Class.git / blobdiff