MICROSOFT_PRESS_EBOOK_PROGRAMMING_WINDOWS_8_APPS_WITH_HTML_CSS_AND_JAVASCRIPT_PDF

You might have noticed that a ProductListing (from the app’s productListings collection) only
contains a name and not a description. This really means that the name is the description and you should
use it as such, rather than using it as another type of identifier, for which you already have productId. In
other words, a product that provides 20 extra levels for a game should be named something like
“Twenty extra levels with new challenges” rather than “extra_levels” because that name will appear in UI.
As you dangle all your product options in front of the user, the user will (I’m being very affirmative
here!) at some point want to purchase one or more of them. When the user taps the appropriate
button, like the Buy Product buttons in the sample (see Figure 17-5 again), the app just needs to call
requestProductPurchaseAsync with the product ID and a Boolean indicating whether the method
should provide a receipt:
currentApp.requestProductPurchaseAsync("product1", false).done(
function () {
if (licenseInformation.productLicenses.lookup("product1").isActive) {
// Purchase was fulfilled; UI is not shown if the user already owns the product.
} else {
// Purchase UI was shown, but the user canceled.
}
},
function () {
// There was an error in the transaction; purchase did not occur
});
If the product already has an active license, requestProductPurchaseAsync will simply call your
completed handler without showing any UI, as none is needed. Otherwise the user will see a series of
prompts to confirm the purchase, including confirmation of their credentials. For the whole flow, see
The in-app purchase user experience for a customer. A typical confirmation message is shown below:
Note that the warning here, which exists to meet regulations in some countries, is not entirely true:
you can also cancel entering your credentials in the next dialog.
When using the CurrentAppSimulator, of course, you won’t see the Store prompts but only another
simple dialog to control the result:
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