MICROSOFT_PRESS_EBOOK_PROGRAMMING_WINDOWS_8_APPS_WITH_HTML_CSS_AND_JAVASCRIPT_PDF

Similarly, change stopBadgePolling in js/scenario5.js to read as follows:
function stopBadgePolling() {
var updater = notifications.BadgeUpdateManager.createBadgeUpdaterForApplication();
updater.clear();
updater.stopPeriodicUpdate();
WinJS.log && WinJS.log("Stopped polling.", "sample", "status");
}
Without these changes, old updates will persist on the tile even after you stop the updates. If you
then change your web service but it has an error in the XML, you won’t see any change on the tile and
might think that the update worked when it really didn’t. Trust me: making these small changes will
simplify your life!
Web Services for Updates
Creating a web service for periodic updates means creating a web page at some given URI whose sole
purpose is to respond to an XmlHttpRequest with XML content for a TileNotification or
BadgeNotification object. Ideally, such a page also handles the scaling, accessibility, and localization
parameters provided in the query string described earlier in “Using Local and Web Images.”
The page can be implemented using whatever language and tools you want, such as PHP or
ASP.NET. In fact, unless you really enjoy programming in Notepad, you’ll certainly want to utilize a good
web development tool! Visual Studio Express for Windows 8 is not actually equipped for this task; the
full version of Visual Studio 2012 is. You might also look into Visual Studio Express 2012 for Web as
another option; more on this in a moment. If you use ASP.NET, remember again that you can again
employ the Notifications Extensions Library for easily creating the tile XML.
Some examples of pages that provide tile updates are given in the Creating a great tile experience
(Part 2) post on the Windows Developers Blog. Based on those examples, here is a trivial (but functional)
one-liner PHP page that will post XML for a badge update with the current day of the month:
Drop this code into a .php file (see HelloTiles/dayofmonthservice.php in the companion content for
this chapter) on whatever web server you might have access to and voila! There’s a very basic service
that delivers badge updates. You can use this in Scenario 5 of the Push and periodic notifications
client-side sample—enter your page’s URI in the box, press the button to start polling, and then check
the sample’s tile on the Start screen tile. In a few seconds you should see the day of the month appear as
a badge. (Of course, with this ultrasimplistic example the date will reflect the local time on the web
server rather than the device, which could be completely mismatched. A real service would be sensitive
to time zone and other locale-specific considerations.)
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