BizTalk™ Unleashed

Functoid Implementation

In this section, we will implement the Selector functoid design from the preceding section using C++ and ATL. For alternative implementation technologies, check the BizTalk product samples. They provide functoids in Visual Basic and C#.

The implementation in this section comprises the following items:

• A script implementing the Selector() functionality

• A COM coclass implementing IFunctoid

It is reasonable to ask why there is a mixture of COM and script. Script is not sufficient. BizTalk Mapper needs additional metadata for how to incorporate the functoid onto the mapper's diagram surface. BizTalk Mapper also uses COM categories to catalog available functoids.

We cannot eliminate the script entirely in favor of a COM object ...