If I have an React/Redux single page application that has - say - a customers page that lists businesses that are customers, and from there each customer can be accessed with a URL like this:

`/customer/1`

From there, the page lists contacts at said customer, and the user can drill into individual contacts at that customer:

`/contact/58`

On the contact page, there are details about the customer, and a few details about the customer they work for.

This all works fine if the user navigates through the pages as I've described. But if the user goes straight to /contact/58, there won't be any state about the customer to display.

Finally, the question: how should Redux-based SPAs cope with this?