MacKuba

(See full blog post here)

Current full photo library access: your app has full access to all contents of user’s photo library, can read and write to the photo database

Users usually have thousands or tens of thousands of photos in their library, possibly from many years, but they almost never want an app to have access to all of them (unless this is an app used for photo library management)

New limited mode: you only have access to “user’s limited library selection” – a kind of filter for the photo library

You can only fetch assets and resources related to what the user has chosen to give you access to

When the user updates the selection, your app is notified so you can update your UI

This affects all apps using photo library, even apps that are already live

When the user is asked for access to photos, they can choose:

• Allow access to all
• Don’t allow
• Select photos…

If they choose "Select photos", they're presented with a picker UI in which they can choose the set of photos that your app will be able to see

The selected photo set can be changed in the Settings later

If an app hasn’t made any changes to support this new mode yet, the user will be asked if they want to change selection every time the app accesses the photo library after a restart

How can you use the photo library without requesting access to it at all?

Photo picker:

If your app only needs to let you choose a photo for an avatar, or to post to a chat  ⭢  use system photo picker (PHPickerViewController)

• replacement for UIImagePickerController
• improved with search and multi-select
• doesn’t require user to grant photo library access

See more in Meet the new Photos Picker

Add-only access:

If you only need to save photos and images to the library, you can ask for add-only access

This is useful for e.g. saving an image from a message or post to the phone, or for simple camera apps

See more in What's New in Photos APIs (2017)

Full access makes sense for apps like photo browsing and editing apps, camera or backup apps

Querying for authorization status:

The PHAuthorizationStatus enum that tells you if the app is authorized to use the photo library has a new possible option: .limited

There is also now a second "dimension" to the authorization, represented by a new enum PHAccessLevel, which is either .readWrite or .addOnly

When asking for and checking authorization, you need to specify if you want to check or request read-write access or add-only access by passing a PHAccessLevel parameter

The limited library access only affects read-write access

So here's how you detect if the user has granted you limited access to the library:

Requesting authorization:

When requesting access, it's recommended that you just send a request to the photo library when the user performs an action that requires it, and the popup will appear automatically

This way, it's more clear to the user why exactly the app is requesting access to photos

If you want to request access explicitly without making a request, do:

Note that the popup will only appear if the authorization status isn't determined yet, i.e. if your app hasn't requested it before

Older authorizationStatus() and requestAuthorization(_ handler:) APIs will be deprecated and will just return .authorized even if the access is limited

Other APIs should work the same regardless of access, they will just return fewer items if access is limited

A few exceptions:

• assets created by your app are automatically accessible to your app
• you can’t create or fetch user’s albums in limited mode
• no access to cloud shared assets or albums

UIs to update the limited library selection:

If your app has limited access to the photo library, it's recommended that you add a piece of UI that will let the user update the selection easily without having to go look for it in the Settings app

Here's how you do it:

• add some kind of button that the user can tap to access the selection screen
• when the button is pressed, call PHPhotoLibrary.shared().presentLimitedLibraryPicker(from: viewController)
• monitor changes through PHPhotoLibraryChangeObserver

The selection alert will also appear automatically after each relaunch of your app when the app tries to access a limited photo library

To prevent this automatic popup, add the key PHPhotoLibraryPreventAutomaticLimitedAccessAlert to Info.plist ("Prevent limited photos access alert" in Xcode)

1. 1. Reconsider if your app needs photo library access at all  ⭢  consider using system picker instead, or asking for write-only access
2. 2. Adopt the new authorization APIs
3. 3. Add a button which lets the user access the library selection UI if it makes sense
4. 4. Add the Info.plist key to prevent the alert once you make the necessary UI changes