I will be more than happy to enter it in the support system. I wanted to post it in the forum to gain other feedback. I can appreciate the possibilities of issues with field types but I have to say I think it is ultimately doable as long as there is proper documentation/demonstration(s) provided.
For example, if the rules of the road are, don't setup a combo box to allow a user to add their own entry, then so be it. If the rules state that it won't work if you include alpha characters so be it (but then again, that's what field level validation is for. I'm completely ok with substituting combo boxes with populated quantity values over having a text quantity fields.
I think including a new field type of numeric would be the simplest. Include an option that would enable totaling and it could be stand alone or included in an HTML field (I think that's the newest 4.1 capability - but haven't tried).
For example, 5 line items (A thru E) on the form;
Each item has a new quantity field;
A sixth quantity field is added to the form and the Totaling setting is checked;
This action queries the form for quantity type fields used in this form and allows the user to select only the quantity fields to be included in the total.
Other considerations would be the mathematical operators to be available via drop-down or radio button or designer defined variables such as (field A * variable(4.95))
In place of the designer defined variable, it would be helpful to allow designers to hide any field type but not by role (perhaps they can but I'm not aware). Meaning, a designer could populate a field with a numeric variable such as shipping rate = 4.95 but it didn't need to be visible by the end user. This field needs to be periodically updated by a designer and it needs to be used in one or multiple calculations.
At present, the designer has to update the shipping rate in the client-side event everywhere it reside and this makes everyone sad...
Lastly, since the previous totaling field is a new quantity field type, a second Grand Total quantity field type should be allowed to select any other quantity field type including the previous totaling field.
for starters...