title: iOS 9 "Save PDF to iBooks" with HTML
body: <p><code>iOS 9</code> has a new built-in <code>UIActivity</code> of <code>UIActivityTypeOpenInIBooks</code>. It's in the default list of activities in the UI and in header file but I've not been able to find any API documentation for it (yet). </p>
  
  <p>It appears that <code>UIActivityTypeOpenInIBooks</code> will create a PDF in iBooks just fine if you include UIImages in your <code>UIActivityViewController</code> items or return them in your <code>UIActivityItemProvider</code>.</p>
  
  <p>However I'd like to create a <code>PDF</code> with an HTML page containing text and images like Safari does. But I can't seem to find a way to pass the HTML to <code>UIActivityTypeOpenInIBooks</code> in an acceptable way. </p>
  
  <p>I've tried passing the HTML as a String, <code>NSData</code> and <code>NSURL</code> of a file. I've also tried returning an UIMarkupTextPrintFormatter which works fine for printing but not for <code>UIActivityTypeOpenInIBooks</code>.</p>
  
  <p>Providing an HTML string or the UIMarkupTextPrintFormatter both result in the following errors:</p>
  
  <pre><code>2015-09-08 11:35:46.392 MyApp[4599:1492484] ERROR: attempting to save to URL with no printing source (formatter/renderer) set
  2015-09-08 11:35:46.393 MyApp[4599:1492484] FAILED! due to error in domain UIPrintErrorDomain with error code 4
  </code></pre>
  
  <p><em>Has anyone gotten this working?</em></p>