MACROMEDIA ColdFusion MX, Develop Manual

Page: 329 / 860

Configuring and using session variables 329
Note: ColdFusion lets you delete or change the values of the built-in session variables. As a general
rule, avoid doing so.
If you enable client variables and ColdFusion session management, ColdFusion uses the same
values for the Client and Session scope
CFID
,
CFToken
, and
URLtoken
variables. ColdFusion gets
the values for these variables from the same source, the client’s
CFID
and
CFTOKEN
cookies.
If you use J2EE session management, the Session scope does not include the
Session.CFID
or
Session.CFToken
variables, but does include the
Session.URLToken
and
Session.SessionID
variables. In this case, the
Session.SessionID
is the J2EE session ID and
Session.URLToken
consists of the string
jsessionid=
followed by the J2EE session ID.
Getting a list of session variables
Use the
StructKeyList
function to get a list of session variables, as follows:
<cflock timeout=20 scope="Session" type="Readonly">
<cfoutput> #StructKeyList(Session)# </cfoutput>
</cflock>
Caution: Always put code that accesses session variables inside
cflock
tags.
Creating and deleting session variables
Use a standard assignment statement to create a new session variable, as follows:
<cflock timeout=20 scope="Session" type="Exclusive">
<cfset Session.ShoppingCartItems = 0>
</cflock>
Use the
structdelete
tag to delete a session variable; for example:
<cflock timeout=20 scope="Session" type="Exclusive">
<cfset StructDelete(Session, "ShoppingCartItems")>
</cflock>
Note: If you set session variables on a CFML template that uses the
cflocation
tag, ColdFusion
might not set the variables. For more information, see Macromedia TechNote 22712 at
www.macromedia.com/v1/Handlers/index.cfm?ID=22712&Method=Full.
Session.URLToken ColdFusion session management: A combination of the
CFID
and
CFToken
values in the form
CFID= IDNum &CFTOKEN= tokenNum
. Use this variable
if the client does not support cookies and you must pass the
CFID
and
CFToken
variables from page to page.
J2EE session management: A combination of the
CFID
and
CFToken
cookies and the J2EE session ID, in the form
CFID= IDNum &CFTOKEN= tokenNum &jsessionid= SessionID
.
Session.SessionID A unique identifier for the session.
ColdFusion session management: a combination of the application name
and
CFID
and
CFToken
values.
J2EE session management: the
jsessionid
value.
Variable Description