DBIx::Class::Helper::Row::OnColumnMissing - Configurably handle access of missing columns
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
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.
on_column_missing
You specify the mode by returning the mode from the on_column_missing method. By default the mode returned is warn.
mode
warn
The predefined modes are:
die
Dies with Column $name has not been loaded.
Column $name has not been loaded
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.
on_column_$mode
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');
$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?)
retrieve
Thanks ZipRecruiter for funding the development of this module.
Arthur Axel "fREW" Schmidt <frioux+cpan@gmail.com>
This software is copyright (c) 2019 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.
To install DBIx::Class::Helpers, copy and paste the appropriate command in to your terminal.
cpanm
cpanm DBIx::Class::Helpers
CPAN shell
perl -MCPAN -e shell install DBIx::Class::Helpers
For more information on module installation, please visit the detailed CPAN module installation guide.