As I mentioned in the introduction, the Web is a stateless environment. ColdFusion addresses this problem by providing five variable scopes you can use to maintain state within your application: application, client, cookie, session, and server. These are known as persistent variable scopes because the variables you set within them persist from template to template, in spite of the stateless nature of the Web. This allows you to build applications that can share data across multiple templates without having to pass the values via form fields or URL variables.
Here’s an overview of the types of persistent variables you can use in your ColdFusion applications:
Application variables define
application-wide settings for your application, such as data-source
names and other constants. Application variables are stored in the
server’s RAM and are most often defined in the
Application.cfm template. Application variables
are available to all users accessing the named application and are
often referred to as global variables. Application variables must
always be referenced using the
By default, a single predefined application variable is available:
Application.ApplicationName returns the name of
the application as defined in the
Client variables store values associated with a particular user across multiple sessions. An ...