[Dbix-class] Setting up database connection at run-time

[Matt S Trout]

On Mon, Jan 14, 2008 at 10:18:29AM -0500, Juan Camacho wrote:
> On Jan 13, 2008 8:03 PM, Matt S Trout <dbix-class at trout.me.uk> wrote:
> > On the Catalyst side use Catalyst::Component::InstancePerContext and
> > something approximating
> >
> > my $new = $self->new(%$self);
> > $new->schema($self->schema->connect(<get connect info from $c>);
> >
> > I do something similar quite a lot except that rather than changing the
> > DB connection I'm calling restrict_with_object (provided by
> > DBIx::Class::Schema::RestrictWithObject) to impose a security context.
> > Same basic principle though.
> >
> 
> Thanks Matt for the tip. The InstancePerContext module seems to do the
> trick. Do you see any danger in not creating a new schema each time,
> but simply re-using the existing object and changing the connection if
> the database is different?  Something like:
> 
> sub build_per_context_instance {
>    my ( $self, $c ) = @_;
>    if ( $self->{_database} ne $c->session->{database} ) {
>        $self->schema->connection( ... );
>        $self->{_database} = $c->session->{database};
>    }
>    return $self;
> }

That's horrible. That means if you somehow manage to bypass the context
check or hang onto a reference to the $schema, you're going to hit a random
client's database.

And it doesn't even gain you anything, except maybe an award for 'stupidest
piece of premature optimisation I've seen so far this week'.

-- 
      Matt S Trout       Need help with your Catalyst or DBIx::Class project?
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