To efficiently construct and add a JSON object or array to your request body, use XPRIM_JsonWriter.
It's essential that you use XPRIM_JsonWriter when your JSON data is big (instead of directly instantiating multiple XPRIM_JsonObject or XPRIM_JsonArray), as XPRIM_JsonWriter is designed to perform better for big data.
Define_Com Class(#XPRIM_HttpRequest) Name(#Req)
* Create an XPRIM_JsonWriter to efficiently write JSON data
Define_Com Class(#XPRIM_JsonWriter) Name(#JsonWriter)
* Set the writer to output the JSON to the HTTP request object
#JsonWriter.SetOutputToHttpRequest HttpRequest(#Req)
* Start constructing the object
#JsonWriter.BeginObject
#JsonWriter.WriteString Name('givenName') Value(#EmpGivenName)
#JsonWriter.WriteString Name('lastName') Value(#EmpLastName)
#JsonWriter.WriteString Name('address') Value(#EmpAddress)
#JsonWriter.EndObject
* Execute the request
#Req.DoPost Url('http://yourcompany.com/api/hr/employee')