Feature Request: Key-value pair input widget for Shiny

[RN]

A question /  feature request:

It's very often that one needs a key-value type input in an UI. e.g. For a grocery shopping application I might have the user enter item names and the quantity he wants etc. 

The possible list of grocery items might be thousands so you don't really want an input box for each item. Rather the user dynamically selects his items and you provide a numeric input box for each item he wants. 

I feel to capture something like this there ought to be a standard function or workflow in Shiny. I did get what I wanted (see link below) but the code sounds rather complicated. On the other hand, if there's an easier way to do this I'd love to hear. 

https://statspot.shinyapps.io/app_upload_test_v3/

Can't this be made into a standard UI widget? Where I give it a list of items like usual for a multi select box and the input function does the rest?