Title: Creating a web part that is both a consumer and a provider.
Problem: I needed a web part that receives data from a provider web part. The same web part then passes data onto a consumer web part. I.e. WebPartGetUser (Provider), WebPartShowWeeks (Consumer & Provider) & WebPartShowProductsOrderedinWeek (consumer).
WebPartGetUser - Retrieve the user and passes the user id to the web part WebPartShowWeeks.
WebPartShowWeeks - Consumes the UserId and show weeks where the user placed an order. A drop down list show all the weeks, when the week is selected, the week is passed to the WebPartShowProductsOrderedinWeek web part. This show all the orders placed in a specific week.