MACROMEDIA COLDFUSION MX 61-DEVELOPING COLDFUSION MX, Develop Manual

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274 Chapter 13: Designing and Optimizing a ColdFusion Application
Defining page processing settings
The
cfsetting
tag lets you specify the following page processing attributes that you might want
to apply to all pages in your application:
Often, you use the
cfsetting
tag on individual pages, but you can also use it in your
Application.cfm. For example, you might use it in multi-application environment to override the
ColdFusion MX Administrator settings in one application.
Setting application default variables and constants
You can set default variables and application-level constants on the Application.cfm page. For
example, you can specify the following values:
•
A data source
•
A domain name
•
Style settings, such as fonts or colors
•
Other important application-level variables
Often, an Application.cfm page uses one or more
cfinclude
tags to include libraries of
commonly used code, such as user-defined functions, that are required on many of the
application’s pages.
Processing logins
When an application requires a user to log in, you typically put the
cflogin
tag on the
Application.cfm page. For detailed information on security and creating logins, including an
Application.cfm page that manages user logins, see
Chapter 16, “Securing Applications,”
on page 345 .
Handling errors
You can use the
cferror
tag on your Application.cfm page to specify application-specific error-
handling pages for request, validation, or exception errors, as shown in the example in the
following section. This way you can include application-specific information, such as contact
information or application or version identifiers, in the error message, and you display all error
messages in the application in a consistent manner.
Attribute Use
showDebugOutput Specifies whether to show debugging output. This setting cannot enable
debugging if it is disabled in the ColdFusion MX Administrator. However,
this option can ensure that debugging output is not displayed, even if the
Administrator enables it.
requestTimeout Specifies the page request time-out. If ColdFusion cannot complete
processing a page within the time-out period, it generates an error. This
setting overrides the setting in the ColdFusion MX Administrator. You can
use this setting to increase the page time-out if your application or page
frequently accesses external resources that might be particularly slow,
such as external LDAP servers or web services providers.
enableCFOutputOnly Disables output of text that is not included inside
cfoutput
tags. This
setting can help ensure that extraneous text that might be in your
ColdFusion pages does not get displayed.