Windows 8 HTML5/JavaScript code sample that asks for a review of the app after 5 launches per app version

example.js

// -------------------------------------------------------------------
// Ask for a review after 5 starts of a new version of the Application
// -------------------------------------------------------------------

// Variable to hold the number of time the app started
var startedCount = 0;
// Variable to hold if the user actually accepted to rate the application
var reviewedBefore = false;
// Variables to hold the current and the last version number that was started in a string
var currentPackage = Windows.ApplicationModel.Package;
var currentVersion = currentPackage.current.id.version.major + " - " +
    currentPackage.current.id.version.minor + " - " +
    currentPackage.current.id.version.build + " - " +
    currentPackage.current.id.version.revision;
var lastVersionStarted = currentVersion;

// Check if the variables were stored in the Roaming Settings before loading them
var appData = Windows.Storage.ApplicationData.current;
var roamingSettings = appData.roamingSettings;
if (roamingSettings.values.hasKey("startedCount"))
{
    // If so, read it in the variable
    startedCount = roamingSettings.values["startedCount"];
}
if (roamingSettings.values.hasKey("reviewedBefore")) {
    // If so, read it in the variable
    reviewedBefore = roamingSettings.values["reviewedBefore"];
}
if (roamingSettings.values.hasKey("lastVersionStarted")) {
    // If so, read it in the variable
    lastVersionStarted = roamingSettings.values["lastVersionStarted"];
}

// If the current version is equal to the last version started
if (currentVersion.localeCompare(lastVersionStarted) == 0)
    // Increment the started count by 1
    startedCount++;
else
    // Reset the count because the new version might have fixed some problems or be better
    startedCount = 0;

// And then save it in the Roaming Settings. Note that if the value pair was not
// created before, the method will create it automatically
roamingSettings.values["startedCount"] = startedCount;
roamingSettings.values["lastVersionStarted"] = currentVersion;

// If the app was started 5 times
if (startedCount == 5)
{
    // Change the msg based on the fact that the application was reviewed before or not.
    var msg;
    if (!reviewedBefore)
        msg = "Thank you for using [App Name] for a while now, would you like to review this app?";
    else
        msg = "Thank you for your ongoing use of [App Name]. We made changes since the last time you were asked to review it. Would you mind telling us what you think again?";

    // Create a MessageDialog requesting a review
    var md = new Windows.UI.Popups.MessageDialog(msg, "Please review my app");

    // Build the 3 potential responses using the Commands collection
    // If they say yes, send them to the store
    md.commands.append(new Windows.UI.Popups.UICommand(
        "Yes", 
        function (command) {
            // Change the status to track the fact that they agreed to a review
            reviewedBefore = true;
            // and store it
            roamingSettings.values["reviewedBefore"] = reviewedBefore;
            // Find the FamilyName of the app package
            var familyName = Windows.ApplicationModel.Package.current.id.familyName;
            // Navigate to the store Review Page for the Application
            // *** Note that the next line will launch the store app but will not find your app until
            // *** it is published.
            var uri = new Windows.Foundation.Uri("ms-windows-store:REVIEW?PFN={0}", familyName);
            Windows.System.Launcher.launchUriAsync(uri);
        }));
    // If they say no, just close the dialog box
    md.commands.append(new Windows.UI.Popups.UICommand(
        "No"));
    // If they say ask later, reset the count to 0 giving a grace period of 5 again
    md.commands.append(new Windows.UI.Popups.UICommand(
        "Ask Later",
        function (command) {
            startedCount = 0;
            roamingSettings.values["startedCount"] = startedCount;
        }));
    // Set the command that will be invoked by default
    md.defaultCommandIndex = 0;
    // Set the command to be invoked when escape is pressed
    md.cancelCommandIndex = 1;

    // Display the MessageBox asyncronously.
    md.showAsync();