=for comment POD_DERIVED_INDEX_GENERATED
The following documentation is automatically generated.  Please do not edit
this file, but rather the original, inline with DBIx::Class::FilterColumn
at lib/DBIx/Class/FilterColumn.pm
(on the system that originally ran this).
If you do edit this file, and don't want your changes to be removed, make
sure you change the first line.

=cut

=head1 NAME

DBIx::Class::FilterColumn - Automatically convert column data

=head1 SYNOPSIS

In your Schema or DB class add "FilterColumn" to the top of the component list.

  __PACKAGE__->load_components(qw( FilterColumn ... ));

Set up filters for the columns you want to convert.

 __PACKAGE__->filter_column( money => {
     filter_to_storage => 'to_pennies',
     filter_from_storage => 'from_pennies',
 });

 sub to_pennies   { $_[1] * 100 }

 sub from_pennies { $_[1] / 100 }

 1;

=head1 DESCRIPTION

This component is meant to be a more powerful, but less DWIM-y,
L<DBIx::Class::InflateColumn>.  One of the major issues with said component is
that it B<only> works with references.  Generally speaking anything that can
be done with L<DBIx::Class::InflateColumn> can be done with this component.

=head1 METHODS

=head2 filter_column

 __PACKAGE__->filter_column( colname => {
     filter_from_storage => 'method'|\&coderef,
     filter_to_storage   => 'method'|\&coderef,
 })

This is the method that you need to call to set up a filtered column. It takes
exactly two arguments; the first being the column name the second being a hash
reference with C<filter_from_storage> and C<filter_to_storage> set to either
a method name or a code reference. In either case the filter is invoked as:

  $result->$filter_specification ($value_to_filter)

with C<$filter_specification> being chosen depending on whether the
C<$value_to_filter> is being retrieved from or written to permanent
storage.

If a specific directional filter is not specified, the original value will be
passed to/from storage unfiltered.

=head2 get_filtered_column

 $obj->get_filtered_column('colname')

Returns the filtered value of the column

=head2 set_filtered_column

 $obj->set_filtered_column(colname => 'new_value')

Sets the filtered value of the column

=head1 EXAMPLE OF USE

Some databases have restrictions on values that can be passed to
boolean columns, and problems can be caused by passing value that
perl considers to be false (such as C<undef>).

One solution to this is to ensure that the boolean values are set
to something that the database can handle - such as numeric zero
and one, using code like this:-

    __PACKAGE__->filter_column(
        my_boolean_column => {
            filter_to_storage   => sub { $_[1] ? 1 : 0 },
        }
    );

In this case the C<filter_from_storage> is not required, as just
passing the database value through to perl does the right thing.

=head1 INHERITED METHODS

=over 4

=item L<DBIx::Class::Row>

L<copy|DBIx::Class::Row/copy>, L<delete|DBIx::Class::Row/delete>, L<discard_changes|DBIx::Class::Row/discard_changes>, L<get_from_storage|DBIx::Class::Row/get_from_storage>, L<get_inflated_columns|DBIx::Class::Row/get_inflated_columns>, L<in_storage|DBIx::Class::Row/in_storage>, L<inflate_result|DBIx::Class::Row/inflate_result>, L<insert|DBIx::Class::Row/insert>, L<insert_or_update|DBIx::Class::Row/insert_or_update>, L<is_changed|DBIx::Class::Row/is_changed>, L<is_column_changed|DBIx::Class::Row/is_column_changed>, L<make_column_dirty|DBIx::Class::Row/make_column_dirty>, L<register_column|DBIx::Class::Row/register_column>, L<result_source|DBIx::Class::Row/result_source>, L<set_column|DBIx::Class::Row/set_column>, L<set_columns|DBIx::Class::Row/set_columns>, L<set_inflated_columns|DBIx::Class::Row/set_inflated_columns>, L<throw_exception|DBIx::Class::Row/throw_exception>, L<update_or_insert|DBIx::Class::Row/update_or_insert>

=back

=head1 FURTHER QUESTIONS?

Check the list of L<additional DBIC resources|DBIx::Class/GETTING HELP/SUPPORT>.

=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>.