Advanced policy expressions: Parsing HTTP, TCP, and UDP data
You can configure Advanced policy expressions to evaluate and process the payload in HTTP requests and responses. The payload associated with an HTTP connection includes the various HTTP headers (both standard and custom headers), the body, and other connection information such as the URL. Additionally, you can evaluate and process the payload in a TCP or UDP packet. For HTTP connections, for example, you can check whether a particular HTTP header is present or if the URL includes a particular query parameter.
You can configure expressions to transform the URL encoding and apply HTML or XML “safe” coding for subsequent evaluation. You can also use XPATH and JSON prefixes to evaluate date in XML and JSON files, respectively.
You can also use text-based and numeric Advanced policy expressions to evaluate HTTP request and response data. For more information, see Advanced policy expressions: Evaluating text. and Default Syntax Expressions: Working with Dates, Times, and Numbers.