For the past month or so, I've had the pleasure of doing some development in Lotus Domino. I worked with Domino a lot when I was just starting out my IT career, so I know it's a powerful development platform for client/server applications.
I'm sure if you're reading this, you're developing, or want to be developing, client/server applications with ColdFusion. In the Domino world, we have the Domino server and Lotus Notes client. When developing ColdFusion apps, your client is most likely Internet Explorer, Safari, or Navigator. Your Web server is probably IIS or Apache.
While juggling some Notes work with my standard Web fare, I started thinking about how the Lotus Notes client is different from a browser client. The Notes client is smart. It knows that I like my e-mail sorted by ascending date. It knows which documents I've read and which I haven't. Lotus Notes maintains my state in the application.
The browser, on the other hand, has no idea about any of these things. Every request exists in a vacuum and has no knowledge of any other request. This is a problem that plagues all Web applications, whether you're accessing your gmail account or changing your MSN home page preferences. How does the browser know what's going on? It doesn't, but thankfully in ColdFusion there is an easy way to handle this. This article will talk about ColdFusion's application framework.
cfapplication Tag
At the heart of ColdFusion's application framework is the cfapplication tag. This tag defines how ColdFusion stores application-specific and session-specific data. An application is a group of related actions or functions that work together to give the user a seamless experience. Any of the Web-based e-mail accounts, such as gmail, Yahoo Mail, or Hotmail would serve as a perfect example of a Web application. Even though there is only one application, there can be many users on it. A session keeps track of individual users.
These are the attributes of the cfapplication tag:
