The solution I came up with also uses eval() as there's no global object in JScript which stores the global variables. (In browser JavaScript, there's the global object "window" which holds the global scope.)
However, you'll have to do one extra thing to make it work...
When adding globals using eval() in run-time, the scripting engine will not register those added functions as event handlers. That is, if you add an OnWndIdEvent_Destroyed() event using eval(), it won't get called when the window is destroyed. The trick to get these registered is to use MsgPlus.LoadScriptFile(). When calling LoadScriptFile, the script file is loaded and the global scope is rescanned for event handlers. This results in the newly added functions to be properly registered.
Note that you don't need to trick eval() to be called in the global scope. By simply omitting the "var" keyword, the variable will be created in the global scope. It is generally a bad idea to omit the "var" keyword, but in this case it's sort of acceptable.
Proof of concept:
Javascript code:
var plusWnd = $(MsgPlus).CreateWnd("interface.xml", "yiew", 0);
//[...]
$.wrappers.MsgPlus.CreateWnd = function (XmlFile, WindowId, Options) {
var toEval = "On" + WindowId + "Event_Cancel = function (plusWnd) { $.trigger(plusWnd, '" + WindowId + "Event_Cancel', plusQuery.$A(arguments)); };";
toEval += "On" + WindowId + "Event_Destroyed = function (plusWnd, exitCode) { $.trigger(plusWnd, '" + WindowId + "Event_Destroyed', plusQuery.$A(arguments)); };";
//etc
eval(toEval);
$(MsgPlus).LoadScriptFile("_blank.js"); // black magic happens here
this.original.CreateWnd(XmlFile, WindowId, Options);
}
The loaded script file can contain anything. From my tests, it may not be completely empty though - one character will work though. I think the best options to fill this file with are a single space " " or a semicolon ";". You can even save it as ANSI and save a few bytes, Plus! will still parse it (although Plus! recommends Unicode).
I warned you, it's very hackish and not really recommended (eval is evil but so is LoadScriptFile) but unfortunately it's the only way I could get this to work. Feel free to use it if you think it's "good enough" but think about the consequences. If you decide to use this, don't forget to keep track of the created event handlers so you don't need to redeclare them when creating the same window twice.
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