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
FURTHER QUESTIONS?¶
Check the list of additional DBIC resources.
COPYRIGHT AND LICENSE¶
This module is free software copyright by the DBIx::Class (DBIC) authors. You
can redistribute it and/or modify it under the same terms as the DBIx::Class
library.