Policy Server Guides › Policy Server Configuration Guide › Attributes and Expressions Reference › Functions Available within Expressions › VEXIST Function--Is the Parameter Defined?

VEXIST Function--Is the Parameter Defined?

The VEXIST function accepts a named expression, a context variable, or user attribute and determines whether it is defined. If defined, VEXIST returns TRUE. If not, VEXIST returns FALSE.

Note: In the case of LDAP user directories, SiteMinder cannot determine whether a user attribute is defined and returns FALSE.

Syntax

The VEXIST function has the following format:

VEXIST(#virtual_user_attribute | @user_class | %context_variable | user_attribute_name | user_attribute_string)

Parameters

The VEXIST function accepts one of the following parameters:

#virtual_user_attribute (named expression)

Specifies a named expression that calculates a user attribute.

@user_class (named expression)

Specifies a named expression that tests for membership in a user directory or group.

%context_variable (context variable)

Specifies a context variable.

user_attribute_name (unquoted string)

Specifies a single user attribute.

user_attributes_string (string)

Specifies a string of user attribute names separated by a character.

Return Value

The VEXIST function returns a Boolean.

Example

Return_value=VEXIST(#Age)
Return_value=TRUE

Return_value=VEXIST(@IsDolphin)
Return_value=FALSE

Return_value=VEXIST(%ClientIP)
Return_value=TRUE

Return_value=VEXIST(givenname)
Return_value=FALSE

Return_value=VEXIST('last,first')
Return_value=TRUE