User accessible xml files used in iOS application : <p>I'm building an iOS application which will read in XML files and generate various reports from them.  The application must read them from the local device (in this case an iPad Mini 4).  Users later may upload new XML files to the device (via non-developer type means and not changing the app's source code in any way).  What is a good method for users to upload files to the iPad in a way that my application will have read access to them?  Also, any pointers for XML reading in Swift would be beneficial.   </p>

<p>I'm using Swift 4.0.3 and XCode 9.2 and while I've been a software developer for a long time, I'm relatively new to iOS development.</p>
