So with the items that are still waiting to be complete i wanted to
show how many days the ticket has been open by doing something
like ...
return date.today() - self.issued_date
and then those that are complete ...
return self.competion_date - self.issued_date
Can i create 2 managers for this?? one to return completed, and one to
return not completed??
On Oct 18, 12:04 pm, eyscooby <kenneyschm...@hotmail.com> wrote:
> Ok, this is helping, believe it or not your are helping, I'm probably
> confusing myself mostly.
>
> So the model method explanation was very helpful and you are correct
> that works great, as long as all dates have a completion_date. If a
> new ticket is entered it will fail due to a "NoneType field with
> DateField".
> That line in my model is as such "completed_date =
> DateField(blank=True, null=True)".
>
> The Manager is doing nothing more than returning data from the
> database as a query so that makes sense also.
>
> Step two .. is it because of the NULL=True? can't subtract date field
> from null field (which makes sense), is there a way around that?
> I think this is why i was trying to calculate on a specific filter.
>
> On Oct 18, 3:47 am, Daniel Roseman <dan...@roseman.org.uk> wrote:
>
>
>
> > On Monday, 17 October 2011 20:28:47 UTC+1, eyscooby wrote:
>
> > > Ok, sorry I thought I was starting to understand it a little better,
> > > but now I think I took a step backwards, so if it is ok with you let's
> > > step back and take it a step at a time.
>
> > > So, my first step is wondering if I really need a manager or not??
> > > I was thinking from your first response to me that you might be
> > > suggesting that I did. Let's start there.
> > > If I understand it correctly the Manager is a way of retrieving
> > > specific information.
>
> > > thanks
>
> > Sorry for confusing you. There are two things going on here.
>
> > A Manager is for making custom queries to the database, to return new
> > objects - either one or aquerysetof many. Your original code was using
> > `Model.filter()` and modifying the result, so I suggested that it belonged
> > in a manager.
>
> > A model method is useful when you want to do a separate, non-database,
> > operation on a single object. That's what you really want to do here - given
> > an instance of RequestTicket, calculate how old it is. There's noiteration
> > contained in the method - you iterate through your existingqueryset
> > elsewhere (say in the template) and call days_old on each instance:
>
> > {% for ticket in completed_tickets %}
> > {{ ticket.name }}: {{ ticket.days_old }}
> > {% endif %}
>
> > Or, in your particular circumstance, you simply give the `days_old` method
> > as one of the elements of the `list_display` tuple, and Django takes care of
> > the iterating, calling `days_old` on each row in the changelist.
>
> > So in both of these circumstances, `days_old` simply needs to look like
> > this:
>
> > def days_old(self):
> > return self.competion_date - self.issued_date
>
> > - so it returns a single value, for the one particular ticket instance which
> > it has been called on.
>
> > Hope that helps.
> > --
> > DR.- Hide quoted text -
>
> - Show quoted text -
--
You received this message because you are subscribed to the Google Groups
"Django users" group.
To post to this group, send email to django-users@googlegroups.com.
To unsubscribe from this group, send email to
django-users+unsubscr...@googlegroups.com.
For more options, visit this group at
http://groups.google.com/group/django-users?hl=en.
