[GNC] Customizing invoices (Helmut Eller

[Adrien Monteleone]

On 3/29/22 5:14 PM, John Ralls wrote:
> 
> 
>> On Mar 29, 2022, at 10:33 AM, Adrien Monteleone <adrien.monteleone at lusfiber.net> wrote:
>>
>> The report should simply print the data from the invoice unchanged.
> 
> Be careful what you ask for. The data from the invoice is a rational number, meaning a numerator and a denominator. The print routine will print that as an integer plus a fraction. Remember all of the complaining a few years ago when the price editor showed numbers like 123 + 45/6789? Do you *really* want your invoices to look like that?

Oops, yeah, I was making assumptions and shouldn't do that, certainly 
without investigating. (but then I'd already understand how the number 
is stored)
> 
> Or were you thinking "unchanged" means in decimal form but with no rounding? So if you have say 1/3 your printer keeps printing pages full of '3' until it runs out of paper? ;-)

As I mentioned in IRC, the 'view' of the invoice retains the precision 
'as entered' but the Invoice Report mangles it. To me, that's the bug. A 
user would reasonable expect a printed version of a 'view' to be the 
same data-wise as the view itself.

At the very least, the info should not be so altered as to render it 
incorrect, or at least certainly un-helpful (such as rounding/truncating 
to '0.00' when that is false)

Of course, there are understandable physical screen/paper limits to 
displaying or printing rational numbers. (if someone uses π, ϕ, √2, or 
e, they're own their own!)
> 
> There's a preference for force prices to decimal. If that's set then prices displayed in the Price Database window and the register are rounded to 1/100th of the smallest currency unit in which the price is denominated. For most currencies that's two decimal places so prices are displayed with four. The same could be applied to invoices and other reports.
> 
> I'd think amounts on invoices should be in some integer multiple of the commodity's smallest fraction traded--that's a property of the commodity that you set in the New/Edit Security dialog--and should display as a decimal with the appropriate number of places if the fraction's denominator is a power of 10 or a rational number if not.
> 
> Does that seem reasonable?

It doesn't affect it now, but that would be reasonable at least for 
prices. And if someone is really intent on 4 decimal precision for a 
quantity, perhaps their answer is to rethink the base unit of the 
invoice item. (one could argue that should be the answer here too I suppose)

The bug I filed isn't about these questions though. It is that this 
already is not much of a problem in the Invoice 'view', but that this 
same info is mangled as it makes its way to a printable report.

Regards,
Adrien