DBIx::Class::InflateColumn(3)

NAME
DBIx::Class::InflateColumn - Automatically create references from column data

SYNOPSIS
    # In your table classes
    __PACKAGE__->inflate_column('column_name', {
        inflate => sub { ... },
        deflate => sub { ... },
    });

DESCRIPTION
This component translates column data into references, i.e. "inflating" the column data. It also "deflates" references into an appropriate format for the database.

It can be used, for example, to automatically convert to and from DateTime objects for your date and time fields. There's a convenience component to actually do that though, try DBIx::Class::InflateColumn::DateTime.

It will handle all types of references except scalar references. It will not handle scalar values, these are ignored and thus passed through to SQL::Abstract. This is to allow setting raw values to "just work". Scalar references are passed through to the database to deal with, to allow such settings as " \'year + 1'" and " \'DEFAULT' " to work.

If you want to filter plain scalar values and replace them with something else, see DBIx::Class::FilterColumn.

METHODS

  inflate_column
Instruct DBIx::Class to inflate the given column.

In addition to the column name, you must provide "inflate" and "deflate" methods. The "inflate" method is called when you access the field, while the "deflate" method is called when the field needs to used by the database.

For example, if you have a table "events" with a timestamp field named "insert_time", you could inflate the column in the corresponding table class using something like:

    __PACKAGE__->inflate_column('insert_time', {
        inflate => sub { DateTime::Format::Pg->parse_datetime(shift); },
        deflate => sub { DateTime::Format::Pg->format_datetime(shift); },
    });

(Replace DateTime::Format::Pg with the appropriate module for your database, or consider DateTime::Format::DBI.)

The coderefs you set for inflate and deflate are called with two parameters, the first is the value of the column to be inflated/deflated, the second is the row object itself. Thus you can call "->result_source->schema->storage->dbh" in your inflate/defalte subs, to feed to DateTime::Format::DBI.

In this example, calls to an event's "insert_time" accessor return a DateTime object. This DateTime object is later "deflated" when used in the database layer.

  get_inflated_column
  my $val = $obj->get_inflated_column($col);

Fetch a column value in its inflated state. This is directly analogous to "get_column" in DBIx::Class::Row in that it only fetches a column already retrieved from the database, and then inflates it. Throws an exception if the column requested is not an inflated column.

  set_inflated_column
  my $copy = $obj->set_inflated_column($col => $val);

Sets a column value from an inflated value. This is directly analogous to "set_column" in DBIx::Class::Row.

  store_inflated_column
  my $copy = $obj->store_inflated_column($col => $val);

Sets a column value from an inflated value without marking the column as dirty. This is directly analogous to "store_column" in DBIx::Class::Row.

SEE ALSO

DBIx::Class::Core - This component is loaded as part of the "core" DBIx::Class components; generally there is no need to load it directly

AUTHOR
Matt S. Trout <mst@shadowcatsystems.co.uk>

CONTRIBUTORS
Daniel Westermann-Clark <danieltwc@cpan.org> (documentation)

Jess Robinson <cpan@desert-island.demon.co.uk>

LICENSE
You may distribute this code under the same terms as Perl itself.