Managing Documents in your iOS Apps

WWDC 2018

Client API

File Provider API

Validation tool

• File Provider Validation tests your FileProvider Extension and guides you to fix the issues
• https://developer.apple.com/download/more/

Siri Shortcuts

• File Provider Extension → Info.plist → 
  Add NSFileProviderUsesUniqueItemIdentifiersAcrossDevices

Sample App

• Particles Sample App

Document Picker vs Document Browser

UIDocumentBrowserViewController

• Starting point of your app
  Best practice is to make it the rootViewController
• Full screen
• Open and organize your documents
• All the features of the Files App
• Can be customized
• Present your own UI on top

UIDocumentPickerViewController

• Access files in the cloud (.open)
• Move files to the cloud (.moveToService)
• Copy from/to the cloud (.import, .exportToService)

Example

Document Types

• let the system know which files your application handles

2 Steps

• Declaring the type if it isn’t already declared by iOS
• Claiming that you can view or edit files of this type

Declaring a Type

• More Detail

Declaring a New File Type

• My type conforms to public.data, public.content

Type Conformance

Claiming Support for a Type

Your App and the Sandbox

Coordinating File Access

• NSFileCoordinator, NSFIlePresenter
• Wide Multiple reader/single writer lock
• Instructs the system to download the document

Restore the UI State

How do we implement it?

• Use a Bookmark

Encode/ Decode restorableState example

Open In Place