How to pass an argument to a Javascript Module?

Question

I want to use a Javascript Module (JSM) in a single window of my Xul application, so I can load the resource as I need it.

But, I need to pass the window to the JSM, and I don't know how to do it. Follows my attempt:

In my resource.jsm:

var EXPORTED_SYMBOLS = ["hello"];

function hello(win) {
    win.alert("ALERT FROM JSM!");
}

calling in my window with:

Components.utils.import("resource://module/resource.jsm");
hello(window);

but I get:

win is undefined

in the resource.jsm.

Any idea how to make it work?

Answer 1

It might be causing problems that you named the parameter for your hello function to be window. While window isn't a reserved word, most browser environments treat it as an unassignable constant of sorts. Try:

function hello( obj ) {
    obj.alert("ALERT FROM JSM!");
}

in your module and then invoke it with hello(window), hello(document.window), or hello(this)

---

After reading the Javascript Module documentation, it looks like you'll need to create an object within the module and then change it's property by reference. So in your JSM:

var EXPORTED_SYMBOLS = ["params", "hello"];

params = {
  win: this
};

function hello() {
    params.win.alert("ALERT FROM JSM!");
}

Then you'd invoke by first assigning the window to that parameter and then calling the function:

Components.utils.import("resource://module/resource.jsm");
params.win = window;
hello();

Note: I am not familiar enough with JSMs to know if there's a better way to do this, but this should work.