Citrix Systems 9.2 manual Http.Req.Setcookie, Http.Req.Cookie.Typecasthttpheader

174 Citrix NetScaler Policy Configuration and Reference Guide

Typecasting Operations

Operation	Description
text.TYPECAST_HTTP_	Overrides the behavior of certain methods that are used with
HEADER_T	protocol-aware prefixes. This operator can be used only with
	protocol-aware prefixes that qualify standard HTTP headers,
	that is, prefixes of the format HTTP.REQ.<STANDARD_
	HEADER> (for example, HTTP.REQ.COOKIE and
	HTTP.REQ.SET_COOKIE).
	Protocol-aware prefixes of the format
	HTTP.REQ.<STANDARD_HEADER> are used with
	several methods, such as COUNT and VALUE("string").
	TYPECAST_HTTP_HEADER_T overrides the behavior of
	these methods.
	Following are two examples of how TYPECAST_HTTP_
	HEADER_T overrides the behavior of methods associated
	with protocol-aware prefixes for HTTP headers:
	Example 1: HTTP.REQ.COOKIE.COUNT returns the total
	number of name-value pairs present in Cookie headers.
	HTTP.REQ.COOKIE.TYPECAST_HTTP_HEADER_
	T.COUNT, however, overrides this behavior and returns the
	number of instances of the COOKIE header.
	Example 2: HTTP.REQ.COOKIE.VALUE(n) accepts an
	unsigned integer n (whose value can range from 0 to 14) as
	an argument and selects the value of the first name-value
	pair in the nth instance of the Cookie header, starting from
	the last instance. Therefore,
	HTTP.REQ.COOKIE.VALUE(0) selects the value of the
	first name-value pair in the last instance of the Cookie
	header, HTTP.REQ.COOKIE.VALUE(1) selects the value of
	the first name-value pair in the second to last instance of the
	Cookie header, and so on. When used with TYPECAST_
	HTTP_HEADER_T, however, the method returns the entire
	value of the nth occurrence of the Cookie header, starting
	from the last instance. Therefore, HTTP.REQ.COOKIE.
	TYPECAST_HTTP_HEADER_T.VALUE(0) selects the
	entire value of the last instance of the Cookie header,
	HTTP.REQ.COOKIE.TYPECAST_HTTP_HEADER_T
	.VALUE(1) selects the entire value of the second to last
	instance of the Cookie header, and so on.
	TYPECAST_HTTP_HEADER_T returns an error if used
	with prefixes that are not protocol-aware. It returns an error
	regardless of whether or not the header that is used in the
	prefix is a standard HTTP header. For example, the
	following expression returns an error even though the prefix
	contains a standard header:
	HTTP.REQ.HEADER("Cookie").TYPECAST_HTTP_
	HEADER_T.CONTAINS("abc")