NAME

DBIx::Class::VirtualColumns - Add virtual columns to DBIx::Class schemata

SYNOPSIS

 package Your::Schema::Class;
 use strict;
 use warnings;
 
 use base 'DBIx::Class';
 
 __PACKAGE__->load_components(
   "VirtualColumns",
   "PK",
   "Core",
 );
 
 __PACKAGE__->table("sometable");
 __PACKAGE__->add_columns(qw/dbcol1 dbcol2/);
 __PACKAGE__->add_virtual_columns(qw/vcol1 vcol2 vcol3/);
 
 # =========================================================
 # Somewhere else
 
 my $item = $schema->resultset('Artist')->find($id);
 $item->vcol1('test'); # Set 'test'
 $item->get_column('vcol1'); # Return 'test'
 
 my $otheritem = $schema->resultset('Artist')->create({
     dbcol1 => 'value1',
     dbcol2 => 'value2',
     vcol1  => 'value3',
     vcol2  => 'value4',
 });
 
 $otheritem->vcol1(); # Now is 'value3'
 
 # Get the column metadata just like for a regular DBIC column
 my $info = $result_source->column_info('vcol1');

DESCRIPTION

This module allows to specify 'virtual columns' in DBIx::Class schema classes. Virtual columns behave almost like regular columns but are not stored in the database. They may be used to store temporary information in the DBIx::Class::Row object and without introducting an additional interface.

Most DBIx::Class methods like "set_column", "set_columns", "get_column", "get_columns", "column_info", ... will work with regular as well as virtual columns.

USAGE

Use this module if you want to add 'virtual' columns to a DBIC class which behave like real columns (e.g. if you want to use the "set_column", "get_column" methods)

However if you only want to add non-column data to DBIx::Class::Row objects, then there are easier/better ways:

 __PACKAGE__->mk_group_accessors(simple => qw(foo bar baz));

METHODS

add_virtual_columns

Adds virtual columns to the result source. If supplied key => hashref pairs, uses the hashref as the column_info for that column. Repeated calls of this method will add more columns, not replace them.

 $table->add_virtual_columns(qw/column1 column2/); 
 OR 
 $table->add_virtual_columns(column1 => \%column1_info, column2 => \%column2_info, ...);

The column names given will be created as accessor methods on your "DBIx::Class::Row objects", you can change the name of the accessor by supplying an "accessor" in the column_info hash.

The following options are currently recognised/used by DBIx::Class::VirtualColumns:

•: accessor
Use this to set the name of the accessor method for this column. If not set, the name of the column will be used.

add_virtual_column

Shortcut for add_virtual_columns

has_any_column

Returns true if the source has a virtual or regular column of this name, false otherwise.

has_virtual_column

Returns true if the source has a virtual column of this name, false otherwise.

remove_virtual_columns

 $table->remove_columns(qw/col1 col2 col3/);

Removes virtual columns from the result source.

remove_virtual_column

Shortcut for remove_virtual_columns

_virtual_filter

Splits attributes for regular and virtual columns

new

Overloaded method. "new" in DBIx::Class::Row

get_column

Overloaded method. "get_colum" in DBIx::Class::Row

get_columns

Overloaded method. "get_colums" in DBIx::Class::Row

store_column

Overloaded method. "store_column" in DBIx::Class::Row

set_column

Overloaded method. "set_column" in DBIx::Class::Row

column_info

Overloaded method. "column_info" in DBIx::Class::ResultSource

Additionally returns the HASH key 'virtual' which indicates if the requested column is virtual or not.

update

Overloaded method. "update" in DBIx::Class::Row

CAVEATS

The best way to add non-column data to DBIC objects is to use Class::Accessor::Grouped.

 __PACKAGE__->mk_group_accessors(simple => qw(foo bar baz));

Use DBIx::Class::VirtualColumns only if you rely on DBIx::Class::Row methods like "set_column", "get_column", ...

SUPPORT

This module was just a proof of concept, and is not actively developed anymore. Patches are still welcome though.

Please report any bugs to "bug-dbix-class-virtualcolumns@rt.cpan.org", or through the web interface at <http://rt.cpan.org/Public/Bug/Report.html?Queue=DBIx::Class::VirtualColumns>. I will be notified, and then you'll automatically be notified of progress on your report as I make changes.

AUTHOR

    Maroš Kollár
    CPAN ID: MAROS
    maros [at] k-1.com
    L<http://www.revdev.at>

ACKNOWLEDGEMENTS

This module was written for Revdev <http://www.revdev.at>, a nice litte software company I run with Koki and Domm (<http://search.cpan.org/~domm/>).

COPYRIGHT

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

The full text of the license can be found in the LICENSE file included with this module.