From the details of an invoice, a user should have the capacity to perform a hard delete on a line item from the invoice, if the line item has not been marked as settled. If deletion is attempted, a notification that the line item has been settled should appear and user returned to the invoice details.
Also, from the index of invoices or details of a particular invoice, a user should be able to perform a hard delete on an invoice, unless the invoice has been settled. If settled, the user should be notified that the invoice can not be deleted.
From the details of an invoice, a user should have the capacity to perform a hard delete on a line item from the invoice, if the line item has not been marked as settled. If deletion is attempted, a notification that the line item has been settled should appear and user returned to the invoice details.
Also, from the index of invoices or details of a particular invoice, a user should be able to perform a hard delete on an invoice, unless the invoice has been settled. If settled, the user should be notified that the invoice can not be deleted.