Adding automation to MFC applications

MFC Application 에 자동화를 추가하는 방법을 설명하는 글이다. 정리를 잘 한듯.

Introduction

Automation support in MFC is a great example of why some people don't like MFC: it works great as long as you follow the pre-made examples and use MFC exactly like it was designed, but as soon as you get even a little bit off the beaten path, you're on your own. There are some tutorials in MSDN and articles online that will teach you how to use the 'New project' wizard to generate an automation-enabled application, and some of those even explain some of the working of the code the wizard generates - but unfortunately, that's not always how things go in the Big Bad Real World. Sometimes, you inherit an application that is so old that the initial skeleton was probably generated with the wizard of Visual Studio 4; that has been expanded and hacked on by dozens of people, each with their own understanding (or lack thereof) of the MFC doc/view architecture; that has mutated from an afternoon-hack-proof-of-concept to a piece of software that is critical for the survival of the company; that has had so much surgery that its innards have started to resemble (metaphorically speaking) the leftovers of the struggle that a 3-year old had with a big bowl of spaghetti bolognese. Believe me - not pretty.

So, what can you do when you are asked to add automation support to such an application? Starting over with a fresh application and moving the functionality of the old code back in is not an option. And even if it was, you would find out that the wizard-generated code is built for the idea that the central element of your application's object model is the Document. In some MFC applications, that is simply not the case any more. The only recourse is to figure out exactly what it is that makes automation tick in an MFC application - and add those pieces into the old application.

The obvious way to start is to take an application that is wizard-generated with automation support, and compare it to an application that doesn't have automation support. Add those differences to the old application and you're all set, right? Well, that's partially true - as long as the object model that you want to implement is centered around a Document, as I said before. If you have an object model that doesn't work this way, and you wonder how to get automation to work, read on.

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http://www.codeproject.com/KB/COM/mfc_autom.aspx