Custom file types with iOS Document Interaction Programming

Question

I understand the basic of Document Interaction Programming and UIDocumentInteractionController and I've got it working in my app. However I'm having trouble with specific details of using custom file types. I can't find this addressed in the Apple docs anywhere.

My app uses it's own file types with unique extensions. The files themselves are just plists (xml), but I want the device to treat the files as only openable in my app. Originally I implemented the Document Interaction stuff to treat them as XML while I got it working, but now I want it to treat them as binary files that it needs to hand off to my app.

At the moment, if you have one of my files in an email attachment, iOS first shows the QuickLook (which just spews all the text content of the xml out) before you can choose to Open In. Similarly if one of my files is opened with Safari, Safari just shows the XML and doesn't give you the option to show it in my app at all.

So how do I get iOS to not treat my files as XML? I've changed the "Conforms to UTI" value and "public.mime-type" value in the info.plist, but it seems to have no effect.

Any tips greatly appreciated.

Answer 1

As far as i understand the UIT concept of Apple you cannot just change the file extension to change a potential UIT of the file. If the file contains XML-Data, other apps as well as internal apps might recognize your content and show it internally as XML.

Try to store your Plists with NSPropertyListSerialization NSPropertyListBinaryFormat_v1_0 (then you readble XML)

When you did that without success, why not trying this:

1. use zlib to compress the XML plists afterwards to a zipped file.
2. make a "unique" file extensions (<file>.myappname)

this should "hide" other apps and quick view.

Tell me if one of the ways did work for you.