Understanding the Web Application Framework  
 
 

A ColdFusion application is a collection of application pages that work together. Applications can be as simple as a guest book or as sophisticated as a full Internet commerce system with catalog pages, shopping carts, and reporting. You can combine individual applications to create advanced Web systems.

The ColdFusion Web Application Framework is based on four basic components:

  • Application-level settings and functions
  • Client state management
  • Custom error handling
  • Web server security integration

With these components, you can easily combine your ColdFusion application pages into sophisticated Web applications.

 
 
  Application-level settings and functions  
 
 

ColdFusion offers application-level features that help you control settings, variables, and features available across the entire application. Once you have defined an application, you can use the application-level features in addition to all of the other features in ColdFusion.

The application framework relies on a special application-wide template called Application.cfm, which defines application-level settings and functions such as:

  • The application name
  • Client state management options
  • Application and session variables
  • Default variables
  • Custom error pages
  • Data sources
  • Default style settings
  • Exclusive locks
  • Other application-level constants
 
 
  Note  
 

Because UNIX is case sensitive, the application framework file must be spelled with an initial capital, Application.cfm, for applications that run on UNIX platforms.

See Establishing Application-Level Settings in this chapter.

 
 
  Client state management  
 
 

Because the Web is a stateless system, each connection a browser makes to a Web server is unique in the eyes of the Web server. However, within an application it is important to be able to keep track of users as they move through the pages within the application. This is the definition of client state management.

You can maintain client state by seamlessly tracking variables for a browser as the user moves from page to page in an application. This can be used in place of other methods for tracking client state such as using URL parameters, hidden form fields, and HTTP cookies.

See Enabling Client State Management for more information.

 
 
  Custom error handling  
 
 

Using the CFERROR tag, you can display customized HTML pages when errors occur. This allows you to maintain a consistent look and feel within your application even when errors occur. It also allows you to optionally suppress the display of error information.

CFERROR is often used with CFTRY, CFCATCH, and CFTHROW to customize error pages in ColdFusion applications.

See Generating Custom Error Messages (CFERROR) for more information.

 
 
  Web server security integration  
 
 

You can integrate your applications with the user authentication and security provided by your Web server. In addition, the ColdFusion Server offers a security framework that controls access to applications, pages, data sources, and users. You set the bounds of a security domain using the CFAUTHENTICATE tag.

See Integrating with web server security for more information.



 
 
BackUp LevelNext
 
 

allaire     AllaireDoc@allaire.com
    Copyright © 1998, Allaire Corporation. All rights reserved.