---+ Package ==

%TOC%
=head1 NAME

CGI::Session::Driver::DBI - Base class for native DBI-related CGI::Session drivers

=head1 SYNOPSIS

    require CGI::Session::Driver::DBI;
    @ISA = qw( CGI::Session::Driver::DBI );

=head1 DESCRIPTION

In most cases you can create a new DBI-driven CGI::Session driver by simply creating an empty driver file that inherits from CGI::Session::Driver::DBI. That's exactly what L<sqlite|CGI::Session::Driver::sqlite> does. The only reason why this class doesn't suit for a valid driver is its name isn't in lowercase. I'm serious!

=head2 NOTES

CGI::Session::Driver::DBI defines init() method, which makes DBI handle available for drivers in I<Handle> - object attribute regardless of what C<\%dsn_args> were used in creating session object. Should your driver require non-standard initialization you have to re-define init() method in your F<.pm> file, but make sure to set 'Handle' - object attribute to database handle (returned by DBI->connect(...)) if you wish to inherit any of the methods from CGI::Session::Driver::DBI.

=head1 STORAGE

Before you can use any DBI-based session drivers you need to make sure compatible database table is created for CGI::Session to work with. Following command will produce minimal requirements in most SQL databases:

    CREATE TABLE sessions (
        id CHAR(32) NOT NULL PRIMARY KEY,
        a_session TEXT NOT NULL
    );

Your session table can define additional columns, but the above two are required. Name of the session table is expected to be I<sessions> by default. You may use a different name if you wish. To do this you have to pass I<TableName> as part of your C< \%dsn_args >:

    $s = CGI::Session->new('driver:sqlite', undef, {TableName=>'my_sessions'});
    $s = CGI::Session->new('driver:mysql', undef,
    {
        TableName=>'my_sessions',
        DataSource=>'dbi:mysql:shopping_cart'.
    });

To use different column names, change the 'create table' statement, and then simply do this:

    $s = CGI::Session->new('driver:pg', undef,
    {
        TableName=>'session',
        IdColName=>'my_id',
        DataColName=>'my_data',
        DataSource=>'dbi:pg:dbname=project',
    });

or

    $s = CGI::Session->new('driver:pg', undef,
    {
        TableName=>'session',
        IdColName=>'my_id',
        DataColName=>'my_data',
        Handle=>$dbh,
    });

=head1 DRIVER ARGUMENTS

Following driver arguments are supported:

=over 4

=item DataSource

First argument to be passed to L<DBI|DBI>->L<connect()|DBI/connect()>. If the driver makes
the database connection itself, it will also explicitly disconnect from the database when 
the driver object is DESTROYed.

=item User

User privileged to connect to the database defined in C<DataSource>.

=item Password

Password of the I<User> privileged to connect to the database defined in C<DataSource>

=item Handle

An existing L<DBI> database handle object. The handle can be created on demand
by providing a code reference as a argument, such as C<<sub{DBI->connect}>>.
This way, the database connection is only created if it actually needed. This can be useful
when combined with a framework plugin like L<CGI::Application::Plugin::Session>, which creates
a CGI::Session object on demand as well. 

C<Handle> will override all the above arguments, if any present.

=item TableName

Name of the table session data will be stored in.

=back

=head1 LICENSING

For support and licensing information see L<CGI::Session|CGI::Session>

