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DEVELOPING COLDFUSION 9 APPLICATIONS
Developing CFML Applications
If your application requires utility functions that are used by multiple pages, not just by the methods in Application.cfc,
and you do not use an
onRequest
by running that CFC. As with other ColdFusion pages, Application.cfc can access any CFC in a directory path that is
configured on the ColdFusion Administrator Mappings page. Therefore, use this technique to share utility functions
across applications.
If your Application.cfc defines utility functions that you want available on request pages and does not use an
method, explicitly place the functions in a ColdFusion scope, such as the Request scope, as the following
onRequest
code shows:
<cffunction name="theFunctionName" returntype="theReturnType">
<!--- Function definition goes here. --->
</cffunction>
<cffunction name="OnRequestStart">
<!--- OnRequestStart body goes here --->
<cfset Request.theFunctionName=This.theFunctionName>
</cffunction>
On the request page, you would include the following code:
<cfset myVar=Request.theFunctionName(Argument1...)>
Functions that you define in this manner share the This scope and Variables scope with the Application.cfc file for the
request.
Setting application default variables and constants in onApplicationStart
You can set default variables and application-level constants in Application.cfc. For example, you can do the following:
• Specify a data source and ensure that it is available
• Specify domain name
• Set styles, such as fonts or colors
• Set other application-level variables
You do not have to lock Application scope variables when you set them in the Application.cfc
method.
For details on implementing the
Using the onApplicationEnd method
Use the
onApplicationEnd
such as saving data in memory to a database, or to log the application end. You cannot use this method to display data
on a user page, because it is not associated with any request. The application ends, even if this method throws an
exception. An application that is used often is unlikely to execute this method, except when the server is shut down.
For details on implementing the
Managing sessions in Application.cfc
Use the
and
onSessionStart
resources that are used by multiple pages while a user is accessing your site from during a single browser session. The
session begins when a user first requests a page in your application, and ends when the session times out. For more
information on Session scope and Session variables, see
method, Adobe recommends that you place them in a separate CFC and access them
method, see onApplicationStart in the CFML Reference.
onApplicationStart
method for any clean-up activities that your application requires when it shuts down,
method, see onApplicationEnd in the CFML Reference.
onApplicationEnd
methods to configure and manage user sessions; that is, to control
onSessionEnd
"Using Persistent Data and
Last updated 8/5/2010
onApplicationStart
Locking" on page 301.
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