title: How to download In-App hosted content?
body: <p>I followed <a href="http://www.raywenderlich.com/21081/introduction-to-in-app-purchases-in-ios-6-tutorial">http://www.raywenderlich.com/21081/introduction-to-in-app-purchases-in-ios-6-tutorial</a>
  to set up Apple hosted In-App purchase. It lists the products. When I want to download the products from Apple, I do something like this</p>
  
  <pre><code>-(void) paymentQueue:(SKPaymentQueue *)queue updatedTransactions:(NSArray *)transactions
  {
      for (SKPaymentTransaction * transaction in transactions)
      {
          switch (transaction.transactionState)
          {
              case SKPaymentTransactionStatePurchased:
              {
                  [[SKPaymentQueue defaultQueue] startDownloads:transaction.downloads];
  
      ....
  
  }
  
  -(void) paymentQueue:(SKPaymentQueue *)queue updatedDownloads:(NSArray *)downloads
  {
      NSLog(@"paymentQues");
  
      for (SKDownload *download in downloads)
      {
          switch (download.downloadState)
          {
              case SKDownloadStateActive:
              {
                  NSLog(@"%f", download.progress); break;
               }
      ...
  
  }
  
  -(void) paymentQueue:(SKPaymentQueue *)queue removedTransactions:(NSArray *)transactions
  {
  
  }
  </code></pre>
  
  <p>I started the download in updatedTransactions, then updatedDownloads is called by Apple with downloadState == Active. Then next, Apple calls removedTransaction without ever actually start the download. The download progress is always 0% and updatedDownloads is never called with downloadState == Finished.</p>
  
  <p>I don't know why my download never started and why my transaction get removed before the download finishes. Anybody has a working sample?</p>