Client Variables - MACROMEDIA COLDFUSION 5 - INSTALING AND CONFIGURING SERVER Manual

72

Client Variables

Client variables let you perform tasks like determining the IP address of a site
visitor's Web browser. Using information from client variables, you can customize
page content for individual users.
You enable client variable default settings in ColdFusion Server on the Client
Variables page of the Administrator. ColdFusion Server lets you store client variables
in these ways:
Note
You can override settings specified in the Client Variables page using the attributes of
the
Applications book.
The following table compares these storage options:
Storage Type
System registry
Browser cookies
Data source
The operating system registry
As cookies in users' Web browsers
In a data source.
tag. For more information, see the Developing ColdFusion
cfapplication
Advantage
Simple implementation
Good performance
Registry can be exported
easily to other systems
Server-side control
Simple implementation
Good performance
Can be set to expire
automatically
Client-side control
Can use existing data
source
Portable: not tied to the
host system or operating
system
Chapter 5 Basic ColdFusion Server Administration
Disadvantage
Possible restriction of the
registry's maximum size limit on
Windows NT and WIndows 2000
in the Control Panel
Integrated with the host system:
not practical for clustered servers
Solaris, Linux, and HP-UX
registries are text files. Their
registries deliver slow
performance and low scalability.
Users can configure browsers to
disallow cookies
ColdFusion Server limits a
cookie's data to 4 KB
Netscape Navigator allows only
20 cookies from one host;
ColdFusion Server uses three
cookies to store read-only data,
leaving only 17 cookies available
Requires database transaction to
read/write variables
More complex to implement