You may run into cases where the sending application has one set of message standards and the receiving service has its own standards. One such case that I recently ran into with an app trying to initiate a call request via vendor-neutral open standards to Cisco Unified communication system. Obviously, Cisco expects the API request to be in its own format and some process needs to do this translation/transformation to complete the request successfully.
Cisco has good documentation on these Call APIs, also published a sample java application which can be found at https://developer.cisco.com/site/webdialer/
Netscaler Rewrite Action can be levered to transform the HTTP REQ Body to Cisco desired format. Below is a rewrite action that I used to bridge the gap, Basically, replaced the message body to Cisco specifications from the extracted information of the original message.
Expression
Note: Had to break the expression strings in chucks of ~200 char’s to please Netscaler character limitation. Also, while I could have used XPATH to extract the desired information, I went with regex as it turned out to be faster during testing.
"<soapenv:Envelope xmlns:soapenv=\"http://schemas.xmlsoap.org/soap/envelope/\" xmlns:urn=\"urn:WD70\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instanc"+"e\"><soapenv:Header /><soapenv:Body><urn:makeCallSoap soapenv:encodingStyle=\"http://schemas.xmlsoap.org/soap/encoding/\"><in0 xsi:type=\"urn:Credential\"><userID xsi:type=\"xsd:string\">username"+"</userID><password xsi:type=\"xsd:string\">******</password></in0><in1 xmlns:soapenc=\"http://schemas.xmlsoap.org/soap/encoding/\" xsi:type=\"soapenc:string\">" + HTTP.REQ.BODY(HTTP.REQ.CONTENT_LENGTH).AFTER_REGEX(re/<PhoneNumber>/).Before_REGEX(re/<.PhoneNumber>/) + "</in1><in2 xsi:type=\"urn:UserProfile"+"\"><user xsi:type=\"xsd:string\">?</user><deviceName xsi:type=\"xsd:string\">CSF" + HTTP.REQ.BODY(HTTP.REQ.CONTENT_LENGTH).AFTER_REGEX(re/<PhoneAgentID>/).Before_REGEX(re/<.PhoneAgentID>/).TO_UPPER + "</deviceName><lineNumber xsi:type=\"xsd:string\">?</lineNumber></in2></urn:makeCallSoap></soapenv:Body></soapenv:"+"Envelope>"References >
https://www.citrix.com/blogs/2014/03/03/creating-policies-greater-than-255-characters/