Goal to achieve would be to display a popup over current sales order, which enables the user to specify a product template and set several quantities of product variants in a table which will finally passed back to current sales order as individual salesorder lines:

                size

color       quantity


My first approach was to solve the problem client side, displaying a widget as a popup on sales order view and query needed data thorugh javascript api. Unfortunatley i did not figure out how to display a widget as a popup or how to pass sales order context id to the widget.

What would be the best approach to achieve that goal?