DBIx::Class::InflateColumn - Automatically create references from column data |
DBIx::Class::InflateColumn - Automatically create references from column data
# In your table classes __PACKAGE__->inflate_column('column_name', { inflate => sub { ... }, deflate => sub { ... }, });
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.
It will accept arrayrefs, hashrefs and blessed references (objects),
but not scalarrefs. Scalar references are passed through to the
database to deal with, to allow such settings as \'year + 1'
and
\'DEFAULT'
to work.
Instruct the DBIx::Class manpage 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 the DateTime::Format::Pg manpage with the appropriate module for your database, or consider the DateTime::Format::DBI manpage.)
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
on
it, to feed to the DateTime::Format::DBI manpage.
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.
my $val = $obj->get_inflated_column($col);
Fetch a column value in its inflated state. This is directly analogous to get_column in the DBIx::Class::Row manpage in that it only fetches a column already retreived from the database, and then inflates it. Throws an exception if the column requested is not an 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 the DBIx::Class::Row manpage.
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 the DBIx::Class::Row manpage.
Matt S. Trout <mst@shadowcatsystems.co.uk>
Daniel Westermann-Clark <danieltwc@cpan.org> (documentation)
Jess Robinson <cpan@desert-island.demon.co.uk>
You may distribute this code under the same terms as Perl itself.
DBIx::Class::InflateColumn - Automatically create references from column data |