[Catalyst-dev] Bug in Catalyst::Model::DBI .15

[Evan Carroll]

On 5/7/07, Alex Pavlovic <alex at taskforce-1.com> wrote:
> Well, one way of getting to the $dbh before was through the ACCEPT_CONTEXT
> because if you had single Root DBI model, you could just do:
>
> my $dbh = $c->model('Root')->dbh;

This is essentially the way I'm doing it.

> from a model that did not inherit from that root model. The other alternative
> was to use C::M::Proxy instead. This way each model could get access to
> shared $dbh. There is no relation with the $c->user.

> Each time you inherit from a single root model, a database connection has to
> be created for that specific child model. This is not a big overhead though,
> because it's done only once per model, unless the request is in a different
> process or thread ( which is a different story ).

Why is that? The non-Root model's don't inherit from M::DBI at all..
They inherit from M::DBI::Root which uses a single instance of M::DBI

> So to cut the story short, unless you re-implement similiar code used by the
> Proxy in your Root model, then you will still be opening connection initially
> each time you inherit, i.e. there will be separate connection channel for
> each model.

I still don't understand what exactly M::Proxy does, let me show my code.

packagepackage Dealermade::M::DBI;
use base qw/Catalyst::Model::DBI/;
use strict;
use warnings;
use Data::Dumper;
use Carp;

__PACKAGE__->config(
        dsn           => 'dbi:Pg:dbname=dealermade;host=127.0.0.1',
        user          => 'ecarroll',
        password      => 'barfoo',
        options       => { AutoCommit => 1 },
);

sub ACCEPT_CONTEXT {
        my( $self, $c ) = @_;
        bless { %$self, c => $c}, ref ( $self );
}

1;

Dealermade::M::DBI::Root;
use base 'Catalyst::Component';

sub ACCEPT_CONTEXT {
        my( $self, $c ) = @_;
        bless { %$self, c => $c}, ref ( $self );
}

sub dbh {
        my $self = shift;

        $self->{c}->model('DBI')->dbh;

}

package Dealermade::M::DBI::Contact::Pots;
use base 'Dealermade::M::DBI::Root';

sub create {
        my ( $self, $args ) = @_;
        my $dbh = $self->dbh;

        unless ( $self->{_is_valid} ) {
                Carp::croak 'Failed validation'
                        unless $self->validate($args)
                ;
        }

        my $sth = $dbh->prepare('
                INSERT INTO contact.pots ( number, fkey_user )
                VALUES ( ?, ? )
        ');
        $sth->execute(
                $args->{number}
                , $self->user_id
        );

        Carp::croak $sth->errstr if $sth->err;
        Carp::croak 'No modifications' unless $sth->rows;

}

(Has been cut down to show only what is needed)

--
Evan Carroll
System Lord of the Internets
me at evancarroll.com
832-445-8877