DBIx::Class::FilterColumn(3pm) User Contributed Perl Documentation DBIx::Class::FilterColumn(3pm)NAME
DBIx::Class::FilterColumn - Automatically convert column data
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;
DESCRIPTION
This component is meant to be a more powerful, but less DWIM-y, DBIx::Class::InflateColumn. One of the major issues with said component is
that it only works with references. Generally speaking anything that can be done with DBIx::Class::InflateColumn can be done with this
component.
METHODS
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 "filter_from_storage" and "filter_to_storage" set to either a method name or a code reference. In either
case the filter is invoked as:
$row_obj->$filter_specification ($value_to_filter)
with $filter_specification being chosen depending on whether the $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.
get_filtered_column
$obj->get_filtered_column('colname')
Returns the filtered value of the column
set_filtered_column
$obj->set_filtered_column(colname => 'new_value')
Sets the filtered value of the column
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 "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 { $_[1] ? 1 : 0 },
}
);
In this case the "filter_from_storage" is not required, as just passing the database value through to perl does the right thing.
perl v5.14.2 2010-12-25 DBIx::Class::FilterColumn(3pm)
Check Out this Related Man Page
DBIx::Class::InflateColumn(3) User Contributed Perl Documentation DBIx::Class::InflateColumn(3)NAME
DBIx::Class::InflateColumn - Automatically create references from column data
SYNOPSIS
# In your table classes
__PACKAGE__->inflate_column('column_name', {
inflate => sub {
my ($raw_value_from_db, $result_object) = @_;
...
},
deflate => sub {
my ($inflated_value_from_user, $result_object) = @_;
...
},
});
DESCRIPTION
This component translates column data into references, i.e. "inflating" the column data. It also "deflates" references into an appropriate
format for the database.
It can be used, for example, to automatically convert to and from DateTime objects for your date and time fields. There's a convenience
component to actually do that though, try DBIx::Class::InflateColumn::DateTime.
It will handle all types of references except scalar references. It will not handle scalar values, these are ignored and thus passed
through to SQL::Abstract. This is to allow setting raw values to "just work". Scalar references are passed through to the database to deal
with, to allow such settings as " 'year + 1'" and " 'DEFAULT' " to work.
If you want to filter plain scalar values and replace them with something else, see DBIx::Class::FilterColumn.
METHODS
inflate_column
Instruct DBIx::Class to inflate the given column.
In addition to the column name, you must provide "inflate" and "deflate" methods. The "inflate" method is called when you access the field,
while the "deflate" method is called when the field needs to used by the database.
For example, if you have a table "events" with a timestamp field named "insert_time", you could inflate the column in the corresponding
table class using something like:
__PACKAGE__->inflate_column('insert_time', {
inflate => sub {
my ($insert_time_raw_value, $event_result_object) = @_;
DateTime->from_epoch( epoch => $insert_time_raw_value );
},
deflate => sub {
my ($insert_time_dt_object, $event_result_object) = @_;
$insert_time_dt_object->epoch;
},
});
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 result object itself.
In this example, calls to an event's "insert_time" accessor return a DateTime object. This DateTime object is later "deflated" back to the
integer epoch representation when used in the database layer. For a much more thorough handling of the above example, please see
DBIx::Class::DateTime::Epoch
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.
perl v5.18.2 2013-12-16 DBIx::Class::InflateColumn(3)