#158 Sets a step of 1 for the quantity field of InvoiceDetail

The quantity field had a step of 0.01, which was quite inadequate. To ensure an easy update, this PR does not modify the model to change quantity fields by an IntegerField or something, but just changes the step of the corresponding field in the admin interface.

Ticket: #90

Thanks again !

If I'm not mistaken, I think there is a way with far less code to do that same thing.

No obligation at all, your way is perfectly fine. Let me know what you prefer. I'd be happy either way :-)

Oh, you're right, I did'nt know this method.

However, I just tested and it seems it also affects "amount" and "tax" fields (all DecimalFields, in fact). Do you know a workaround for this?

Here is the current code.

class InvoiceDetailInline(LimitedAdminInlineMixin, admin.StackedInline):
    model = InvoiceDetail
    extra = 0
    fields = (('label', 'amount', 'quantity', 'tax'),
              ('offersubscription', 'period_from', 'period_to'))
    formfield_overrides = {
        models.DecimalField: {'widget': forms.NumberInput(attrs={'step': 1})}
    }

Thank you!

However, I just tested and it seems it also affects "amount" and "tax" fields (all DecimalFields, in fact). Do you know a workaround for this?

Oh you are right, I was misreading the documentation. So your way seems the best, tested and approved !