Exposing Undocumented PeopleCode Functions

There are some really useful built-in PeopleCode functions that are available to be consumed, but are not documented in PeopleBooks. Good examples of these functions include the CreateJsonXxx functions used for creating and parsing JSON structures. Developers can expose delivered usages of undocumented functions by doing “Find In” searches in App Designer. This method of uncovering undocumented functions is rather tedious and only exposes the undocumented functions that are being used in delivered code. It is quite possible that there are delivered undocumented functions that are not being used in any delivered code. How can we expose these undocumented, unused functions?

The answer is to use Java to perform type introspection on the delivered PeopleSoft.PeopleCode.Func Java Class. The Func Java Class is mentioned in the From Java to PeopleCode section of PeopleBooks. This class holds methods that replicate the built-in PeopleCode functions. I am unsure if this class holds all of the available built-in functions, but I have discovered that it holds some functions that are undocumented.

I used the Dynamic Java in PeopleCode approach to run the type introspection Java code via JavaScript. Here is the JavaScript program that performs type introspection on the PeopleSoft.PeopleCode.Func Java Class:

var peopleCodeClass = new Packages.PeopleSoft.PeopleCode.Func();
var className = peopleCodeClass.getClass().getName();
var classMethods = peopleCodeClass.getClass().getMethods();

var methods = [];

for (var i = 0; i < classMethods.length; i++) {

   var method = {};
   method.name = classMethods[i].getName();
   method.returnType = classMethods[i].getReturnType().getSimpleName();

   var parameters = [];
   var paramType = classMethods[i].getParameterTypes();
   
   for (var j = 0; j < paramType.length; j++) {
      var parameter = {};
      parameter.type = paramType[j].getSimpleName();
      parameters.push(parameter);
   }

   method.parameters = parameters;
   methods.push(method);
}

var classDetails = {};
classDetails.name = className;
classDetails.methods = methods;

var result = JSON.stringify(classDetails);

The program puts the function information in a JSON string and stores it in the result JavaScript variable. This program can be stored in an HTML Object (PSM_TEST in this example) and be invoked from PeopleCode as follows:

Local JavaObject &joManager = CreateJavaObject("javax.script.ScriptEngineManager");
Local JavaObject &joEngine = &joManager.getEngineByName("JavaScript");
Local string &sProgram = GetHTMLText(HTML.PSM_TEST);

&joEngine.eval(&sProgram);

Local string &sResult = &joEngine.get("result").toString();

Return &sResult;

The &sResult PeopleCode variable will hold the function information represented as a JSON string. In my 8.56.12 environment there are 1032 methods listed in the JSON output:

You can also use the same approach to expose the available system variables (%UserId, etc.) that PeopleCode has to offer. To do this, you can replace the first line in the JavaScript program to reference the PeopleSoft.PeopleCode.SysVar Java Class:

var peopleCodeClass = new Packages.PeopleSoft.PeopleCode.SysVar();

And the output will be similar to the Func Class output:

Keep in mind that the type introspection JavaScript program does not perform any data type mappings. You will notice some Java-specific parameter and return data types listed in the script’s output. The PeopleCode and Java Data Types Mapping section of PeopleBooks can be referenced to understand the corresponding PeopleCode types.