Here's some code that demonstrates the general logic when using in app purchases.
// app title InAppPurchaseSetTitle ( "your app title" )
// keys for android InAppPurchaseSetKeys ( "key1", "" )
// products that our app has InAppPurchaseAddProductID ( "productID1", 0 ) InAppPurchaseAddProductID ( "productID2", 0 )
// initial set up InAppPurchaseSetup ( )
// restore any non-consumable products on iOS - automatic on Amazon and Android InAppPurchaseRestore ( )
if GetInAppPurchaseAvailable ( 0 ) // user owns productID1 endif
if GetInAppPurchaseAvailable ( 1 ) // user owns productID2 endif
do // buy first product when pointer is pressed if GetPointerPressed ( ) = 1 BuyProduct ( 0 ) endif
sync ( ) loop
function BuyProduct ( ID as integer ) // start activation InAppPurchaseActivate ( ID )
// wait until it is done do // display info on screen print ( "waiting to complete purchase..." ) // check if it has finished if GetInAppPurchaseState ( ) = 1 exit endif
sync ( ) loop
if GetInAppPurchaseAvailable ( ID ) = 1 // provide the content endif endfunction