Chapter 24 -- Workgroup and Workflow Technologies

Chapter 24

About This Chapter

Collaboration data objects (CDO) is a popular technology to add messaging functionality to business applications. This technology was not always referred to as CDO. In Microsoft Exchange Server 4.0, the name was OLE Messaging, which was changed in Exchange Server 5.0 to Active Messaging. In Exchange Server 5.5, Microsoft decided to change the name again to describe the technology more intuitively. This time the name became Collaboration Data Objects. However, innovation never stops at Microsoft. Although the name hasn't changed, distinct versions of CDO evolved, called CDO for Exchange Server 5.5 (CDO 1.2.1) and CDO for Windows NT Server (CDONTS). Different CDO versions are also available for Microsoft Windows 2000 Server (CDOSYS) and Microsoft Exchange 2000 Server (CDOEX). Furthermore, Exchange 2000 Server introduces CDO for Exchange Management (CDOEXM) and CDO for Workflow (CDOWF). Short, CDO provides a vast spectrum of programmable objects. It is a comprehensive technology to build custom solutions that exactly match the needs of your organization.

CDO for Exchange 2000 Server will install cleanly over CDO for Windows 2000 Server. You do not need to recompile or reprogram any solutions that have been developed with CDOSYS. CDO 1.2.1 and CDOEX, however, are not alike. CDO 1.2.1 is based on the Messaging Application Programming Interface (MAPI). Because Exchange 2000 Server is fully backward compatible, CDO 1.2.1 remains an important programming technology that comes with Microsoft Outlook 2000 and is also installed as part of Exchange 2000 Server. CDOEX, on the other hand, is based on an entirely new approach that retreats from MAPI and employs the technologies of the Microsoft Web Storage System. It relies on the Exchange Object Linking and Embedding Database (ExOLE DB) provider, which can only be used directly on the server. This is not a disadvantage. CDOEX is a perfect choice for programming Microsoft Active Server Pages (ASPs), ActiveX DLLs, Microsoft Web Storage System event sinks, and Windows 2000 services that run on the server.

This chapter concentrates on the new CDO technologies for Exchange 2000 Server. Lesson 1 introduces CDOEX. Lesson 2 then illustrates how to use CDOEXM to manage an Exchange 2000 server. Lesson 3 discusses CDOWF and related tools to design workflow processes.

Before You Begin

To complete this chapter:

• You need to be familiar with the concepts of ActiveX Data Objects (ADO), ExOLEDB, and the Web Storage System, as explained in Chapter 23, "Microsoft Exchange 2000 Web Storage System."
• You should have a general understanding of the essential Exchange 2000 components and their interaction with each other, as covered in Chapter 3, "Microsoft Exchange 2000 Server Architecture."
• You only need a minimum level of skills for Visual Basic Scripting Edition (VBScript) to follow the code samples in this chapter. All code samples are also available in the form of .vbs files in the Sample_Scripts\Chapter24 folder on the Supplemental Course Materials CD-ROM.