When a purchase has invoices, you could relate (keyword) from the purchase to invoices and open all invoices in new tab.
In case you create a new invoice, default invoice type is customer.
Control invoice type from the “origin”:
A- Not allow new button when list records from a purchase or sale
B- Default invoice type depends from the origin (from the context, … a parameter keyword…)
- A purchase with invoices
- Click “Invoices (1)” button.
- Create a new invoice. Default invoice type is “customer” when the origin is a purchase (supplier).