Javascript Runtime Error: 'Application is undefined'

Question

I need to know if this is correct. I'm just beginning in app development using WinJS. I've identified the source of the problem and got rid of it but I don't know if that's the correct method.Please help!

// Optimize the load of the application and while the splash screen is
// shown, execute high priority scheduled work.

ui.disableAnimations();
var p = ui.processAll().then(function () {
    //return nav.navigate(nav.location || Application.navigator.home, nav.state);
        return nav.navigate(nav.location || app.local, nav.state)
    }).then(function () {
        return sched.requestDrain(sched.Priority.aboveNormal + 1);
    }).then(function () {
        ui.enableAnimations();
    });

The problem is in the first .then(). The commented line was the default line, I've changed it for the app to work.I've absolutely no idea what it is.Please tell me what it means and what is changed. By the way, 'app' is WinJS.Application and Application is a WinJS namespace in navigator.js where the home property is located.

Answer 1

This error would suggest that navigator.js isn't being loaded by the time this code is executed. The Application namespace, which is entirely arbitrary and unrelated to WinJS.Application, is defined only in navigator.js, so if that file isn't loaded that namespace won't exist.

A WinJS namespace, by the way, is just a formalization of a module pattern in JavaScript that helps you keep the global namespace from getting cluttered. Declaring a namespace like navigator.js does it:

 WinJS.Namespace.define("Application", {
     PageControlNavigator: WinJS.Class.define( 

just creates a single object in the global namespace called "Application" and then defines members for it. (You can change "Application" to anything you want, by the way. Nothing else in navigator.js relies on it, and navigator.js is something that comes from the app templates in Visual Studio and isn't part of WinJS itself.)

So again, my suspicion is that you don't have (or whatever the proper path is) in your default.html, the path to it isn't correct, or that perhaps it's being loaded after the other code is trying to execute. Try setting breakpoints on WinJS.Namespace.define and see if that file is loaded and the breakpoint gets hit.