Parent List has a lookup with multiple promotional items. Once user chooses a promotional item, I want user to be able to add a quantity to that specific item. User should be able to select Multiple items, and assign unique quantities to each item. Any help would be great!!
I would suggest to consider the following solution:
The most curious thing here is the mentioned custom control for displaying "Items with quantities" column. It would look something like this:
When you press
Each time you change quantity, the control must update the corresponding item in the "Quantities" list, following way:
Thus, since the Items with quantities column is linked to the Title column of the "Quantities" list, values of this column will be displayed by default as "[Title] ([Quantity])", this is I assume quite acceptable. Hence, you will be able to avoid any display customizations.
In order to do this you would have to add the following components:
But this would still not display the quantities on the list view.
Alternatively, you could create a multi-valued Custom Field Type to handle input and display, but this is is likely to be even more difficult.