projekt kivitendo

our @EXPORT = qw(move_position_up move_position_down reorder_list configure_acts_as_list);

my %list_spec;

sub configure_acts_as_list {

  my ($class, %params) = @_;

  $list_spec{$class} = {

    group_by    => $params{group_by},

    column_name => $params{column_name},

  };

}

sub get_group_by_where {

  my ($self)   = @_;

  my $group_by = get_spec(ref $self, 'group_by') || [];

  $group_by    = [ $group_by ] if $group_by && !ref $group_by;

  my @where    = map { my $value = $self->$_; defined($value) ? "(${_} = " . $value . ")" : "(${_} IS NULL)" } @{ $group_by };

  return join ' AND ', @where;

}

  return 1 if defined $self->$column;

  my $table        = $self->meta->table;

  my $where        = get_group_by_where($self);

  $where           = " WHERE ${where}" if $where;

  my $sql = <<SQL;

    SELECT COALESCE(max(${column}), 0)

    FROM ${table}

    ${where}

SQL

  my $max_position = $self->db->dbh->selectrow_arrayref($sql)->[0];

  $self->$column($max_position + 1);

  return 1 unless defined $self->$column;

  my $table    = $self->meta->table;

  my $value    = $self->$column;

  my $group_by = get_group_by_where($self);

  $group_by    = ' AND ' . $group_by if $group_by;

  my $sql      = <<SQL;

    UPDATE ${table}

    SET ${column} = ${column} - 1

    WHERE (${column} > ${value}) ${group_by}

SQL

  $self->db->dbh->do($sql);

  my $table                                        = $self->meta->table;

  my $old_position                                 = $self->$column;

  my ($comp_sel, $comp_upd, $min_max, $plus_minus) = $direction eq 'up' ? ('<', '>=', 'max', '+') : ('>', '<=', 'min', '-');

  my $group_by                                     = get_group_by_where($self);

  $group_by                                        = ' AND ' . $group_by if $group_by;

  my $sql                                          = <<SQL;

    SELECT ${min_max}(${column})

    FROM ${table}

    WHERE (${column} ${comp_sel} ${old_position})

      ${group_by}

SQL

  my $new_position = $self->db->dbh->selectrow_arrayref($sql)->[0];

  $sql = <<SQL;

    UPDATE ${table}

    SET ${column} = ${old_position}

    WHERE (${column} = ${new_position})

     ${group_by};

SQL

  $self->db->dbh->do($sql);

  my $column = get_spec(ref $self, 'column_name');

  return $column if $column;

sub get_spec {

  my ($class, $key) = @_;

  return undef unless $list_spec{$class};

  return $list_spec{$class}->{$key};

}

column

The column name to use can be configured via L<configure_acts_as_list>.

=head1 CLASS FUNCTIONS

=over 4

=item C<configure_acts_as_list %params>

Configures the mixin's behaviour. C<%params> can contain the following

values:

=over 2

=item C<column_name>

The name of the column containing the position. If not set explicitly

then the mixin will use C<sortkey> if the model contains such a column

(only for legacy tables) and C<position> otherwise.

=item C<group_by>

An optional column name (or array reference of column names) by which

to group. If a table contains items for several distinct sets and each

set has its own sorting then this can be used.

An example would be requirement spec text blocks. They have a column

called C<output_position> that selects where to output the text blocks

(either before or after the sections). Furthermore these text blocks

each belong to a single requirement spec document. So each combination

of C<requirement_spec_id> and C<output_position> should have its own

set of C<position> values, which can be achieved by configuring this

mixin with C<group_by = [qw(requirement_spec_id output_position)]>.

=back

=back

=head1 INSTANCE FUNCTIONS