Citrix Systems Network Router 9.2 User Manual

The advanced expression engine provides prefixes that are specific to parsing 
VPN or Clientless VPN data. This data includes the following:

•

Host names, domains, and URLs in VPN traffic.

•

Protocols in the VPN traffic.

HTTP.REQ.URL.PATH.

IGNORE_EMPTY_ELEMENTS 

Ignores the empty elements in the list. For example, if 
the element delimiter in the list is a comma, the 
following list has an empty element following a=10:

a=10,b=11, ,c=89 

The element following b=11 is not considered an empty 
element. 

As another example, consider the following header:

Cust_Header : 123,,24, ,15 

The following expression returns a value of 4:

http.req.header("Cust_Header").typecast_

list_t(',').ignore_empty_elements.count 

The following expression returns a value of 5:

http.req.header("Cust_Header").typecast_
list_t(',')

. count 

HTTP.REQ.URL.QUERY.

IGNORE_EMPTY_ELEMENTS 

This method ignores the empty elements in a name-
value list. For example, if the list delimiter is a 
semicolon, the following list has an empty element 
following a=10:

a=10;;b=11; ;c=89 

The element following b=11 is not considered an empty 
element. 

For example, consider the following header:

Cust_Header : a=1;;b=2; ;c=3 

The following expression returns a value of 4:

http.req.header("Cust_Header").typecast_

nvlist_t('=',';').ignore_empty_elements.

count 

The following expression returns a value of 5:

http.req.header("Cust_Header").typecast_

nvlist_t('=',';'). count