Problem grasping webpart communication

Question

Hi, I'm having trouble understanding some web part communication code, and how to make it work as needed. I'm fairly new to web parts, so I figure I'm over complicating it.

I have

public interface IFormTypeRID
{
    int FormTypeRID { get; }
}

For this page, I have a ListControl on the left which is a web part. When you select something with this list control, it posts back and sends this interface to the MainForm web part So I have this on the receiving end:

private IFormTypeRID theProvider;

[ConnectionConsumer("FormTypeRID Consumer", "FormTypeRIDConsumer")]
public void InitializeProvider(IFormTypeRID provider)
{
    theProvider = provider;
    FormTypeRID = theProvider.FormTypeRID;
}

Now, my problem is that InitializeProvider happens after Page_Load.

This means that when a post back happens from inside the MainForm webpart, the FormTypeRID is never sent in. Well, thats easy just store it in view state or a hidden field.

But theres the problem.

How do I act on FormTypeRID being set if it's after PageLoad. Currently, I just have a setter method that calls the appropriate functions. This is troublesome however because the code in the setter must be executed twice. This is because FormTypeRID must be set in Page_Load because it is unknown whether our provider will be giving us our FormTypeRID or not(because we do not know if the post back happened because of the other webpart, or because of the FormMain)

I know I explained that horribly. But basically, how do you tell if a postback happened(and therefore a page_load) from one webpart(the provider) or another?(the consumer)

Answer 1

The answer to all of this is non-trivial.

I ended up writing my own "webpart communication" which actually ended up being a lot cleaner than ASP.Net's and it will work during Init and Load and so on.