Enhanced Float-Value Display Options

Description of the need

An enhanced level of flexibility in how float-values are displayed is needed.

This is a [modified] snip from the admin page of my site at "/admin/structure/types/manage/sell-line-item/display/default":

My current use case

I have a quantity field which can refer to units of (each), (lbs), (packets of X), etc. I need to be able to specify a value such as 215.326 in the case of pounds (for instance) or 5,000 in the case of 5k units (or items). So it makes sense to display the full "scale" of the float in the case of lbs, whereas I'd rather the value for quantity of items read as "5,000" instead or "5,000.000."

This feature would furthermore provide for the value "0.3750" to be displayed as "0.375" or ".375", either of which might be preferable over "0.3750".

I have been unable to find a module which provides this functionality, though it is possible that views offers this option. In any case, it seems appropriate that it would be offered in core, since it is so closely tied with the basic Display Mode functions.

Proposed solution

Looking at the BD documentation, it appears to me that this might be accomplished by adding two booleans to the data structure, and some code to the functions:

function number_field_formatter_info()
function number_field_formatter_settings_form()

...and others, found in the number.module.