Connected Web Part Series - Part 2

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). 

Hypothesis:
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.