Hello all,
There's a new branch "ordered_handle_updates" that adds some
functionality to the DBIx::Class::Ordered component.
Firstly, there is a new move_to_group() method as detailed
in a previous post to the list. But far more interestingly,
there is now support for reordering and moving between
groups *implicitly* by overloading the update() method.
Any comments/criticism would be greatly appreciated, as I am
a little green when it comes to Class::C3 method dispatch.
The move_to and move_to_group methods need to bypass the
overloaded update() but I couldn't see a way to do that short
of a flag in the object instance.
I've attached the code portion of the patch for convenience.
Best,
Brian Kirkbride
=== lib/DBIx/Class/Ordered.pm
==================================================================
--- lib/DBIx/Class/Ordered.pm (/mirrors/cat/branches/DBIx-Class-current)
(revision 2112)
+++ lib/DBIx/Class/Ordered.pm
(/mirrors/cat/branches/DBIx-Class/ordered_handle_updates) (revision 2112)
@@ -290,10 +290,55 @@
});
my $op = ($from_position>$to_position) ? '+' : '-';
$rs->update({ $position_column => \"$position_column $op 1" });
+ $self->{_ORDERED_INTERNAL_UPDATE} = 1;
$self->update({ $position_column => $to_position });
return 1;
}
+=head2 move_to_group
+
+ $item->move_to_group( $group, $position );
+
+Moves the object to the specified position of the specified
+group, or to the end of the group if $position is undef.
+1 is returned on success, and 0 is returned if the object is
+already at the specified position of the specified group.
+
+=cut
+
+sub move_to_group {
+ my( $self, $to_group, $to_position ) = @_;
+ my $position_column = $self->position_column;
+ my $grouping_column = $self->grouping_column;
+
+ return 0 if ( ! defined($to_group) );
+ return 0 if ( defined($to_position) and $to_position < 1 );
+ return 0 if ( $self->$grouping_column==$to_group and defined($to_position)
and $self->$position_column==$to_position );
+
+ # Move to end of current group and adjust siblings
+ $self->move_last;
+
+ $self->$grouping_column($to_group);
+ my $new_group_count =
$self->result_source->resultset->search({$self->_grouping_clause()})->count();
+ if (!defined($to_position) or $to_position > $new_group_count) {
+ $self->{_ORDERED_INTERNAL_UPDATE} = 1;
+ $self->update({ $position_column => $new_group_count + 1 });
+ }
+ else {
+ my @between = ($to_position, $new_group_count);
+
+ my $rs = $self->result_source->resultset->search({
+ $position_column => { -between => [ @between ] },
+ $self->_grouping_clause(),
+ });
+ $rs->update({ $position_column => \"$position_column + 1" });
+ $self->{_ORDERED_INTERNAL_UPDATE} = 1;
+ $self->update({ $position_column => $to_position });
+ }
+
+ return 1;
+}
+
=head2 insert
Overrides the DBIC insert() method by providing a default
@@ -310,6 +355,42 @@
return $self->next::method( @_ );
}
+=head2 update
+
+Overrides the DBIC update() method by checking for a change
+to the position and/or group columns. Movement within a
+group or to another group is handled by repositioning
+the appropriate siblings. Position defaults to the end
+of a new group if it has been changed to undef.
+
+=cut
+
+sub update {
+ my $self = shift;
+
+ if ($self->{_ORDERED_INTERNAL_UPDATE}) {
+ delete $self->{_ORDERED_INTERNAL_UPDATE};
+ return $self->next::method( @_ );
+ }
+
+ $self->set_columns($_[0]) if @_ > 0;
+ my %changes = $self->get_dirty_columns;
+ $self->discard_changes;
+
+ my $pos_col = $self->position_column;
+ my $grp_col = $self->grouping_column;
+ if (defined($grp_col) and exists $changes{$grp_col}) {
+ $self->move_to_group(
+ delete($changes{$grp_col}),
+ exists($changes{$pos_col}) ? delete($changes{$pos_col}) :
$self->$pos_col
+ );
+ }
+ elsif (exists $changes{$pos_col}) {
+ $self->move_to(delete $changes{$pos_col});
+ }
+ return $self->next::method( \%changes );
+}
+
=head2 delete
Overrides the DBIC delete() method by first moving the object
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