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.