NAME
DBIx::Class::Helper::Row::OnColumnMissing - Configurably handle access of missing columns
SYNOPSIS
package MyApp::Schema::Result::Account;
use parent 'DBIx::Class::Core';
__PACKAGE__->load_components(qw(Helper::Row::OnColumnMissing));
__PACKAGE__->table('Account');
__PACKAGE__->add_columns(
id => {
data_type => 'integer',
is_auto_increment => 1,
},
name => {
data_type => 'varchar',
size => 25,
},
book => { data_type => 'text' },
);
sub on_column_missing { 'die' }
1;
Or with DBIx::Class::Candy:
package MyApp::Schema::Result::Account;
use DBIx::Class::Candy -components => ['Helper::Row::OnColumnMissing'];
table 'Account';
column id => {
data_type => 'integer',
is_auto_increment => 1,
};
column amount => {
data_type => 'float',
keep_storage_value => 1,
};
column book => { data_type => 'text' };
sub on_column_missing { 'die' }
1;
Elsewhere:
my $row = $rs->search(undef, { columns => [qw( id name )] })->one_row;
$row->book # dies
DESCRIPTION
This module is written to handle the odd condition where you have limited the columns retrieved from the database but accidentally access one of the ones not included. It is configurable by tweaking the on_column_missing
return value.
MODES
You specify the mode
by returning the mode
from the on_column_missing
method. By default the mode
returned is warn
.
The predefined modes are:
die
-
Dies with
Column $name has not been loaded
. warn
-
Warns with
Column $name has not been loaded
. nothing
-
Does nothing
You can predefine more modes by defining methods named on_column_$mode
, and also override the default modes by overriding the corresponding methods. If you need ad-hoc behavior you can return a code reference and that will be called as a method on the object.
ADVANCED USAGE
If for some reason you find that you need to change your mode
at runtime, you can always replace the on_column_missing
with an accessor. For example:
__PACKAGE__->mk_group_accessors(inherited => 'on_column_missing');
__PACKAGE__->on_column_missing('warn');
Elsewhere:
$row->on_column_missing('die');
If you are especially crazy you could even do something like this:
$row->on_column_missing(sub {
my ($self, $column) = @_;
$self
->result_source
->resultset
->search({ id => $self->id })
->get_column($column)
->single
});
Though if you do that I would make it a named mode (maybe retrieve
?)
THANKS
Thanks ZipRecruiter for funding the development of this module.
AUTHOR
Arthur Axel "fREW" Schmidt <frioux+cpan@gmail.com>
COPYRIGHT AND LICENSE
This software is copyright (c) 2024 by Arthur Axel "fREW" Schmidt.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.