[Catalyst] Best practice for database connections, where $c is not available?

[Ash Berlin]

On 31 Dec 2008, at 15:37, Oliver Charles wrote:

> Hi,
>
> This has hit me a few times, and I've just encountered it again, so I
> thought it would be good to ask those wiser than I :)
>
> There have been a few times where I could do with querying the
> database (which I'd normally do through $c->model), but this is not
> available. For example, I've added the option for users to specify how
> to display dates on our website, through a variety of formats. I
> thought the best way to do this, would be using a Template Toolkit
> plugin:
>
>    [% USE user_date %]
>    The date is [% user_date.format(some_date) %].
>
> However, this plugin needs to access the user preferences model
> ($c->model('UserPreference')->date_format($user)). Should I be
> instantiating this model (the Catalyst model is a very lightweight
> wrapper around a non-catalyst specific model) - or is there a better
> option?
>
> - Ollie
>
>

The way I do this is by overriding template_vars in my View:TT (which  
has $c available) to provide format_date and format_datetime subs/ 
closures (I just let the user specify a TZ, but the idea is the same):

sub template_vars {
     my ($self, $c) = @_;

     return (
         $self->NEXT::template_vars($c),
         format_datetime => sub { $self->format_datetime($c, @_) },
         format_date     => sub { $self->format_date($c, @_) },
     );
};

sub format_datetime {
     my ($self, $c, $date) = @_;
     return unless $date;

     if ($c->user && $c->user->timezone) {
       $date->set_time_zone('UTC');
       $date->set_time_zone($c->user->timezone);
     }

     my $str = $date->strftime("%e %B %Y, %R");
     $str =~ s/^ //;
     return $str;
}