my $position_column = $self->position_column;
- # FIXME this needs to be wrapped in a transaction
{
+ my $guard = $self->result_source->schema->txn_scope_guard;
+
my ($direction, @between);
if ( $from_position < $to_position ) {
$direction = -1;
}
my $new_pos_val = $self->_position_value ($to_position); # record this before the shift
- $self->_ordered_internal_update({ $position_column => $self->null_position_value }); # take the row out of the picture for a bit
+
+ # 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 }} ) ) ) {
+ $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;
+
return 1;
}
}
return $self->move_to ($to_position);
}
- # FIXME this needs to be wrapped in a transaction
{
+ my $guard = $self->result_source->schema->txn_scope_guard;
+
# Move to end of current group to adjust siblings
$self->move_last;
$self->_ordered_internal_update;
+ $guard->commit;
+
return 1;
}
}
return $self->next::method( \%changes, @_ );
}
- # FIXME this needs to be wrapped in a transaction
{
+ my $guard = $self->result_source->schema->txn_scope_guard;
+
# if any of our grouping columns have been changed
if (grep { exists $changes{$_} } ($self->_grouping_columns) ) {
$self->move_to(delete $changes{$position_column});
}
- return $self->next::method( \%changes, @_ );
+ my @res;
+ my $want = wantarray();
+ if (not defined $want) {
+ $self->next::method( \%changes, @_ );
+ }
+ elsif ($want) {
+ @res = $self->next::method( \%changes, @_ );
+ }
+ else {
+ $res[0] = $self->next::method( \%changes, @_ );
+ }
+
+ $guard->commit;
+ return $want ? @res : $res[0];
}
}
sub delete {
my $self = shift;
- # FIXME this needs to be wrapped in a transaction
- {
- $self->move_last;
- return $self->next::method( @_ );
+
+ my $guard = $self->result_source->schema->txn_scope_guard;
+
+ $self->move_last;
+
+ my @res;
+ my $want = wantarray();
+ if (not defined $want) {
+ $self->next::method( @_ );
}
+ elsif ($want) {
+ @res = $self->next::method( @_ );
+ }
+ else {
+ $res[0] = $self->next::method( @_ );
+ }
+
+ $guard->commit;
+ return $want ? @res : $res[0];
}
-=head1 Methods for extending Ordered
+=head1 METHODS FOR EXTENDING ORDERED
You would want to override the methods below if you use sparse
(non-linear) or non-numeric position values. This can be useful
my $num_pos = $item->_position;
-Returns the absolute numeric position of the current object, with the
+Returns the B<absolute numeric position> of the current object, with the
first object being at position 1, its sibling at position 2 and so on.
By default simply returns the value of L</position_column>.
my $pos_value = $item->_position_value ( $pos )
-Returns the value of L</position_column> of the object at numeric
+Returns the B<value> of L</position_column> of the object at numeric
position C<$pos>. By default simply returns C<$pos>.
=cut
__PACKAGE__->_initial_position_value(0);
-This method specifies a value of L</position_column> which is assigned
+This method specifies a B<value> of L</position_column> which is assigned
to the first inserted element of a group, if no value was supplied at
insertion time. All subsequent values are derived from this one by
L</_next_position_value> below. Defaults to 1.
my $new_value = $item->_next_position_value ( $position_value )
-Returns a position value that would be considered C<next> with
+Returns a position B<value> that would be considered C<next> with
regards to C<$position_value>. Can be pretty much anything, given
that C<< $position_value < $new_value >> where C<< < >> is the
SQL comparison operator (usually works fine on strings). The
$item->_shift_siblings ($direction, @between)
-Shifts all siblings with position in the range @between (inclusive)
-by one position as specified by $direction (left if < 0, right if > 0).
-By default simply increments/decrements each L<position_column> value
-by 1.
+Shifts all siblings with B<positions values> in the range @between
+(inclusive) by one position as specified by $direction (left if < 0,
+ right if > 0). By default simply increments/decrements each
+L<position_column> value by 1, doing so in a way as to not violate
+any existing constraints.
+
+Note that if you override this method and have unique constraints
+including the L<position_column> the shift is not a trivial task.
+Refer to the implementation source of the default method for more
+information.
=cut
sub _shift_siblings {
# position column is part of a unique constraint, and do a
# one-by-one update if this is the case
- my %uc = $self->result_source->unique_constraints;
- if (grep { $_ eq $position_column } ( map { @$_ } (values %uc) ) ) {
+ if (grep { $_ eq $position_column } ( map { @$_ } (values %{{ $self->result_source->unique_constraints }} ) ) ) {
my $rs = $shift_rs->search ({}, { order_by => { "-$ord", $position_column } } );
# FIXME - no need to inflate each row
=head2 _group_rs
-This method returns a resultset containing all memebers of the row
+This method returns a resultset containing all members of the row
group (including the row itself).
=cut
return 1;
}
+=head2 _ordered_internal_update
+
+This is a short-circuited method, that is used internally by this
+module to update positioning values in isolation (i.e. without
+triggering any of the positioning integrity code).
+
+Some day you might get confronted by datasets that have ambiguous
+positioning data (i.e. duplicate position values within the same group,
+in a table without unique constraints). When manually fixing such data
+keep in mind that you can not invoke L<DBIx::Class::Row/update> like
+you normally would, as it will get confused by the wrong data before
+having a chance to update the ill-defined row. If you really know what
+you are doing use this method which bypasses any hooks introduced by
+this module.
+
+=cut
+
sub _ordered_internal_update {
my $self = shift;
local $self->{_ORDERED_INTERNAL_UPDATE} = 1;
=head1 AUTHOR
-Aran Deltac <bluefeet@cpan.org>
+ Original code framework
+ Aran Deltac <bluefeet@cpan.org>
+
+ Constraints support and code generalisation
+ Peter Rabbitson <ribasushi@cpan.org>
=head1 LICENSE
projects / dbsrgits/DBIx-Class.git / blobdiff