[Catalyst] Date::Calc and Date::Calendar with Catalyst?

[Dave Morriss]

On 23/02/07, Jonathan Rockway <jon at jrock.us> wrote:
> Dave Morriss wrote:
> > Question 1: Will I need to build my own plugin to achieve what I want,
> > or is there another way?
>
> It's unlikely that you'll want to use a plugin.  Plugins should be
> reserved for things that modify Catalyst's usual request cycle.
> Pagecache, Static::Simple, and ConfigLoader are good examples of
> plugins; Prototype is a bad example.

I thought, based on the way C::P::DateTime is put together, that
plugins are also used as a way of making non-Catalyst modules
available in the Catalyst namespace. From the way I interpret the
documentation you referred to I reckon I _could_ do something like
that. You seem to be recommending against it.

> I'm not exactly sure what you're trying to do, but it sounds like you
> want a regular Perl module:
>
>   package MyOrg::Calendar;
>   use base 'Exporter';
>   my @EXPORT = qw(workdays_between_dates);
>
>   sub workdays_between_dates {
>      my ($from, $to) = @_;
>      return 42; # modify to taste
>   }

Yes, I'm doing something like this already.

In brief, I need to do some basic stuff such as:
    - define the organisation's non-workday calendar, which
Date::Calendar can do
    - manage a holiday allocation per person (different people have
different rates, and can
      earn more by working overtime)
    - record "bookings" which have a start date & am/pm, end date &
am/pm, and a duration
    - compute duration such that the guy who takes the Friday before a
Monday holiday and
      the Tuesday after is billed for only 2 days; decrement the allocation
    - etc

I'm using Date::Calc date objects, delta times, and related stuff for
all of this, so I'd like constant data and
Date::Calc/Date::Calendar/DateTime methods as well as my own to be
available in several controllers.

> Then in Catalyst, you'd do something like:
>
>   package MyOrg::Vacations::Controller::GiveMeADayOff;
>   use base 'Catalyst::Controller';
>   use MyOrg::Calendar;
>
>   sub get_a_day_off : Path {
>       my ($self, $c, $date) = @_;
>
>       $c->stash(template => 'day_off.tt');
>
>       my $last_day_off =
>        $c->model('Vacataions')->get_last_vacation_day_for($c->user);
>
>       if(workdays_between_dates($last_day_off, $date) > 5){
>          $c->stash(error =>
>                    "Only one vacation day per week is allowed,
>                     slacker!");
>       }
>       else {
>          $c->model('Vacations')->add_vacation($date, $c->user);
>       }
>
>       ... # you get the idea
>   }
>
> Hope this helps a bit.

Yes, thanks. It's broadly what I am doing now. Some of the basic
functionality is working using this technique.

> Basically you should read up on writing Perl
> modules; I think that's what you really want here.  man perlmod should help.

Ow! I didn't realise I was so transparent. Yes, I'm an old-fashioned
programmer from the pre-OO days :-)

> > Question 2: Is there a plugin writer's HOWTO?
>
> There is; at:
>
> http://search.cpan.org/~jrockway/Catalyst-Manual-5.700501/lib/Catalyst/Manual/WritingPlugins.pod
>
> But I don't think you need a plugin.

OK, thanks.

-- 
Dave Morriss