axiom-photo-library-ref

name	axiom-photo-library-ref
description	Reference — PHPickerViewController, PHPickerConfiguration, PhotosPicker, PhotosPickerItem, Transferable, PHPhotoLibrary, PHAsset, PHAssetCreationRequest, PHFetchResult, PHAuthorizationStatus, limited library APIs
license	MIT
metadata	{"version":"1.0.0"}

Photo Library API Reference

Quick Reference

// SWIFTUI PHOTO PICKER (iOS 16+)
import PhotosUI

@State private var item: PhotosPickerItem?

PhotosPicker(selection: $item, matching: .images) {
    Text("Select Photo")
}
.onChange(of: item) { _, newItem in
    Task {
        if let data = try? await newItem?.loadTransferable(type: Data.self) {
            // Use image data
        }
    }
}

// UIKIT PHOTO PICKER (iOS 14+)
var config = PHPickerConfiguration()
config.selectionLimit = 1
config.filter = .images
let picker = PHPickerViewController(configuration: config)
picker.delegate = self

// SAVE TO CAMERA ROLL
try await PHPhotoLibrary.shared().performChanges {
    PHAssetCreationRequest.creationRequestForAsset(from: image)
}

// CHECK PERMISSION
let status = PHPhotoLibrary.authorizationStatus(for: .readWrite)

---

PHPickerViewController (iOS 14+)

System photo picker for UIKit apps. No permission required.

Configuration

import PhotosUI

var config = PHPickerConfiguration()

// Selection limit (0 = unlimited)
config.selectionLimit = 5

// Filter by asset type
config.filter = .images

// Use photo library (enables asset identifiers)
config = PHPickerConfiguration(photoLibrary: .shared())

// Preferred asset representation
config.preferredAssetRepresentationMode = .automatic  // default
// .current - original format
// .compatible - converted to compatible format

Filter Options

// Basic filters
PHPickerFilter.images
PHPickerFilter.videos
PHPickerFilter.livePhotos

// Combined filters
PHPickerFilter.any(of: [.images, .videos])

// Exclusion filters (iOS 15+)
PHPickerFilter.all(of: [.images, .not(.screenshots)])
PHPickerFilter.not(.livePhotos)

// Playback style filters (iOS 17+)
PHPickerFilter.any(of: [.cinematicVideos, .slomoVideos])

Presenting

let picker = PHPickerViewController(configuration: config)
picker.delegate = self
present(picker, animated: true)

Delegate

extension ViewController: PHPickerViewControllerDelegate {

    func picker(_ picker: PHPickerViewController, didFinishPicking results: [PHPickerResult]) {
        picker.dismiss(animated: true)

        for result in results {
            // Get asset identifier (if using PHPickerConfiguration(photoLibrary:))
            let identifier = result.assetIdentifier

            // Load as UIImage
            result.itemProvider.loadObject(ofClass: UIImage.self) { object, error in
                guard let image = object as? UIImage else { return }
                DispatchQueue.main.async {
                    self.displayImage(image)
                }
            }

            // Load as Data
            result.itemProvider.loadDataRepresentation(forTypeIdentifier: UTType.image.identifier) { data, error in
                guard let data else { return }
                // Use data
            }

            // Load Live Photo
            result.itemProvider.loadObject(ofClass: PHLivePhoto.self) { object, error in
                guard let livePhoto  object    {  }
                
            }
        }
    }
}

PHPickerResult Properties

Property	Type	Description
itemProvider	NSItemProvider	Provides selected asset data
assetIdentifier	String?	PHAsset identifier (if using photoLibrary config)

---

PhotosPicker (SwiftUI, iOS 16+)

SwiftUI view for photo selection. No permission required.

Basic Usage

import SwiftUI
import PhotosUI

// Single selection
@State private var selectedItem: PhotosPickerItem?

PhotosPicker(selection: $selectedItem, matching: .images) {
    Label("Select Photo", systemImage: "photo")
}

// Multiple selection
@State private var selectedItems: [PhotosPickerItem] = []

PhotosPicker(
    selection: $selectedItems,
    maxSelectionCount: 5,
    matching: .images
) {
    Text("Select Photos")
}

Filters

// Images only
matching: .images

// Videos only
matching: .videos

// Images and videos
matching: .any(of: [.images, .videos])

// Live Photos
matching: .livePhotos

// Exclude screenshots (iOS 15+)
matching: .all(of: [.images, .not(.screenshots)])

Selection Behavior

PhotosPicker(
    selection: $items,
    maxSelectionCount: 10,
    selectionBehavior: .ordered,  // .default, .ordered, .continuous
    matching: .images
) { ... }

Behavior	Description
.default	Standard multi-select
.ordered	Selection order preserved
.continuous	Live updates as user selects (iOS 17+)

Embedded Picker (iOS 17+)

PhotosPicker(
    selection: $items,
    maxSelectionCount: 10,
    selectionBehavior: .continuous,
    matching: .images
) {
    Text("Select")
}
.photosPickerStyle(.inline)  // Embed in view hierarchy
.photosPickerDisabledCapabilities([.selectionActions])
.photosPickerAccessoryVisibility(.hidden, edges: .all)

Style	Description
.presentation	Modal sheet (default)
.inline	Embedded in view
.compact	Single row

Disabled Capability	Effect
.search	Hide search bar
.collectionNavigation	Hide albums
.stagingArea	Hide selection review
.selectionActions	Hide Add/Cancel

Accessory Visibility	Description
.hidden, .automatic, .visible	Per edge

HDR Preservation (iOS 17+)

PhotosPicker(
    selection: $items,
    matching: .images,
    preferredItemEncoding: .current  // Don't transcode, preserve HDR
) { ... }

Encoding	Description
.automatic	System decides format
.current	Original format, preserves HDR
.compatible	Force compatible format

Loading Images from PhotosPickerItem

// Load as Data (most reliable)
if let data = try? await item.loadTransferable(type: Data.self),
   let image = UIImage(data: data) {
    // Use image
}

// Custom Transferable for direct UIImage
struct ImageTransferable: Transferable {
    let image: UIImage

    static var transferRepresentation: some TransferRepresentation {
        DataRepresentation(importedContentType: .image) { data in
            guard let image = UIImage(data: data) else {
                throw TransferError.importFailed
            }
            return ImageTransferable(image: image)
        }
    }
}

// Usage
if let result = try? await item.loadTransferable(type: ImageTransferable.self) {
    let image = result.image
}

PhotosPickerItem Properties

Property	Type	Description
itemIdentifier	String	Unique identifier
supportedContentTypes	[UTType]	Available representations

PhotosPickerItem Methods

// Load transferable
func loadTransferable<T: Transferable>(type: T.Type) async throws -> T?

// Load with progress
func loadTransferable<T: Transferable>(
    type: T.Type,
    completionHandler: @escaping (Result<T?, Error>) -> Void
) -> Progress

---

PHPhotoLibrary

Access and modify the photo library.

Authorization Status

// Check current status
let status = PHPhotoLibrary.authorizationStatus(for: .readWrite)

// Request authorization
let newStatus = await PHPhotoLibrary.requestAuthorization(for: .readWrite)

PHAuthorizationStatus

Status	Description
.notDetermined	User hasn't been asked
.restricted	Parental controls limit access
.denied	User denied access
.authorized	Full access granted
.limited	Access to user-selected photos only (iOS 14+)

Access Levels

// Read and write
PHPhotoLibrary.requestAuthorization(for: .readWrite)

// Add only (save photos, no reading)
PHPhotoLibrary.requestAuthorization(for: .addOnly)

Limited Library Picker

// Present picker to expand limited selection
@MainActor
func presentLimitedLibraryPicker() {
    guard let viewController = UIApplication.shared.keyWindow?.rootViewController else { return }
    PHPhotoLibrary.shared().presentLimitedLibraryPicker(from: viewController)
}

// With completion handler
PHPhotoLibrary.shared().presentLimitedLibraryPicker(from: viewController) { identifiers in
    // identifiers: asset IDs user added
}

Performing Changes

// Async changes
try await PHPhotoLibrary.shared().performChanges {
    // Create, update, or delete assets
}

// With completion handler
PHPhotoLibrary.shared().performChanges({
    // Changes
}) { success, error in
    // Handle result
}

Change Observer

class PhotoObserver: NSObject, PHPhotoLibraryChangeObserver {

    override init() {
        super.init()
        PHPhotoLibrary.shared().register(self)
    }

    deinit {
        PHPhotoLibrary.shared().unregisterChangeObserver(self)
    }

    func photoLibraryDidChange(_ changeInstance: PHChange) {
        // Handle changes
        guard let changes = changeInstance.changeDetails(for: fetchResult) else { return }

        DispatchQueue.main.async {
            // Update UI with new fetch result
            let newResult = changes.fetchResultAfterChanges
        }
    }
}

---

PHAsset

Represents an asset in the photo library.

Fetching Assets

// All photos
let allPhotos = PHAsset.fetchAssets(with: .image, options: nil)

// With options
let options = PHFetchOptions()
options.sortDescriptors = [NSSortDescriptor(key: "creationDate", ascending: false)]
options.fetchLimit = 100
options.predicate = NSPredicate(format: "mediaType == %d", PHAssetMediaType.image.rawValue)

let recentPhotos = PHAsset.fetchAssets(with: options)

// By identifier
let assets = PHAsset.fetchAssets(withLocalIdentifiers: [identifier], options: nil)

Asset Properties

Property	Type	Description
localIdentifier	String	Unique ID
mediaType	PHAssetMediaType	.image, .video, .audio
mediaSubtypes	PHAssetMediaSubtype	.photoLive, .photoPanorama, etc.
pixelWidth	Int	Width in pixels
pixelHeight	Int	Height in pixels
creationDate	Date?	When taken
modificationDate	Date?	Last modified
location	CLLocation?	GPS location
duration	TimeInterval	Video duration
isFavorite	Bool	Marked as favorite
isHidden	Bool	In hidden album

PHAssetMediaType

Type	Value
.unknown	0
.image	1
.video	2
.audio	3

PHAssetMediaSubtype

Subtype	Description
.photoPanorama	Panoramic photo
.photoHDR	HDR photo
.photoScreenshot	Screenshot
.photoLive	Live Photo
.photoDepthEffect	Portrait mode
.videoStreamed	Streamed video
.videoHighFrameRate	Slo-mo video
.videoTimelapse	Timelapse
.videoCinematic	Cinematic mode

---

PHAssetCreationRequest

Create new assets in the photo library.

Creating from UIImage

try await PHPhotoLibrary.shared().performChanges {
    PHAssetCreationRequest.creationRequestForAsset(from: image)
}

Creating from File URL

try await PHPhotoLibrary.shared().performChanges {
    PHAssetCreationRequest.creationRequestForAssetFromImage(atFileURL: imageURL)
}

// For video
try await PHPhotoLibrary.shared().performChanges {
    PHAssetCreationRequest.creationRequestForAssetFromVideo(atFileURL: videoURL)
}

Creating with Resources

try await PHPhotoLibrary.shared().performChanges {
    let request = PHAssetCreationRequest.forAsset()

    // Add photo resource
    let options = PHAssetResourceCreationOptions()
    options.shouldMoveFile = true  // Move instead of copy

    request.addResource(with: .photo, fileURL: photoURL, options: options)

    // Set creation date
    request.creationDate = Date()

    // Set location
    request.location = CLLocation(latitude: 37.7749, longitude: -122.4194)
}

Deferred Photo Proxy (iOS 17+)

Save camera proxy photos for background processing:

// From AVCaptureDeferredPhotoProxy callback
try await PHPhotoLibrary.shared().performChanges {
    let request = PHAssetCreationRequest.forAsset()

    // Use .photoProxy to trigger deferred processing
    request.addResource(with: .photoProxy, data: proxyData, options: nil)
}

Resource Type	Description
.photo	Standard photo
.video	Video file
.photoProxy	Deferred processing proxy (iOS 17+)
.adjustmentData	Edit adjustments

Getting Created Asset

try await PHPhotoLibrary.shared().performChanges {
    let request = PHAssetCreationRequest.forAsset()
    request.addResource(with: .photo, fileURL: url, options: nil)

    // Get placeholder for later fetching
    let placeholder = request.placeholderForCreatedAsset
    // placeholder.localIdentifier available after changes complete
}

Custom Albums

// Create a custom album
func getOrCreateAlbum(named title: String) async throws -> PHAssetCollection {
    // Check if album already exists
    let fetchOptions = PHFetchOptions()
    fetchOptions.predicate = NSPredicate(format: "title = %@", title)
    let existing = PHAssetCollection.fetchAssetCollections(with: .album, subtype: .any, options: fetchOptions)
    if let album = existing.firstObject { return album }

    // Create new album
    var placeholder: PHObjectPlaceholder?
    try await PHPhotoLibrary.shared().performChanges {
        let request = PHAssetCollectionChangeRequest.creationRequestForAssetCollection(withTitle: title)
        placeholder = request.placeholderForCreatedAssetCollection
    }
    guard let id = placeholder?.localIdentifier,
          let album = PHAssetCollection.fetchAssetCollections(withLocalIdentifiers: [id], options: nil).firstObject
    else { throw PhotoError.albumCreationFailed }
    return album
}

// Save photo to custom album
 ( : , : )   {
      .shared().performChanges {
         assetRequest  .creationRequestForAsset(from: image)
          placeholder  assetRequest.placeholderForCreatedAsset,
               albumRequest  (for: album)  {  }
        albumRequest.addAssets([placeholder]  )
    }
}

---

PHFetchResult

Ordered list of assets from a fetch.

Properties

Property	Type	Description
count	Int	Number of items
firstObject	T?	First item
lastObject	T?	Last item

Methods

// Access by index
let asset = fetchResult.object(at: 0)
let asset = fetchResult[0]

// Get multiple
let assets = fetchResult.objects(at: IndexSet(0..<10))

// Iteration
fetchResult.enumerateObjects { asset, index, stop in
    // Process asset
    if shouldStop {
        stop.pointee = true
    }
}

// Check contains
let contains = fetchResult.contains(asset)
let index = fetchResult.index(of: asset)

---

PHImageManager

Request images from assets.

Request Image

let manager = PHImageManager.default()

let options = PHImageRequestOptions()
options.deliveryMode = .highQualityFormat
options.resizeMode = .exact
options.isNetworkAccessAllowed = true  // For iCloud photos

let targetSize = CGSize(width: 300, height: 300)

manager.requestImage(
    for: asset,
    targetSize: targetSize,
    contentMode: .aspectFill,
    options: options
) { image, info in
    guard let image else { return }

    // Check if this is the final image
    let isDegraded = (info?[PHImageResultIsDegradedKey] as? Bool) ?? false
    if !isDegraded {
        // Final high-quality image
    }
}

PHImageRequestOptions

Property	Type	Description
deliveryMode	PHImageRequestOptionsDeliveryMode	Quality preference
resizeMode	PHImageRequestOptionsResizeMode	Resize behavior
isNetworkAccessAllowed	Bool	Allow iCloud download
isSynchronous	Bool	Synchronous request
progressHandler	Block	Download progress
allowSecondaryDegradedImage	Bool	Extra callback during deferred processing (iOS 17+)

Secondary Degraded Image (iOS 17+)

For photos undergoing deferred processing, get an intermediate quality image:

let options = PHImageRequestOptions()
options.allowSecondaryDegradedImage = true

// Callback order:
// 1. Low quality (immediate, isDegraded = true)
// 2. Medium quality (new, isDegraded = true) -- while processing
// 3. Final quality (isDegraded = false)

Delivery Modes

Mode	Description
.opportunistic	Fast thumbnail, then high quality
.highQualityFormat	Only high quality
.fastFormat	Only fast/degraded

Request Video

manager.requestAVAsset(forVideo: asset, options: nil) { avAsset, audioMix, info in
    guard let avAsset else { return }
    // Use AVAsset for playback
}

// Or export to file
manager.requestExportSession(
    forVideo: asset,
    options: nil,
    exportPreset: AVAssetExportPresetHighestQuality
) { session, info in
    session?.outputURL = outputURL
    session?.outputFileType = .mp4
    session?.exportAsynchronously { ... }
}

---

PHChange

Represents changes to the photo library.

Getting Change Details

func photoLibraryDidChange(_ changeInstance: PHChange) {
    guard let changes = changeInstance.changeDetails(for: fetchResult) else { return }

    // Check what changed
    let hasIncrementalChanges = changes.hasIncrementalChanges
    let insertedIndexes = changes.insertedIndexes
    let removedIndexes = changes.removedIndexes
    let changedIndexes = changes.changedIndexes

    // Get new fetch result
    let newResult = changes.fetchResultAfterChanges

    // Update collection view
    DispatchQueue.main.async {
        if hasIncrementalChanges {
            collectionView.performBatchUpdates {
                if let removed = removedIndexes {
                    collectionView.deleteItems(at: removed.map { IndexPath(item: $0, section: 0) })
                }
                if let inserted = insertedIndexes {
                    collectionView.insertItems(at: inserted.map { IndexPath(item: $0, section: 0) })
                }
                if let changed = changedIndexes {
                    collectionView.reloadItems(at: changed.map { IndexPath(item: $0, section: 0) })
                }
            }
        }  {
            collectionView.reloadData()
        }
    }
}

---

Common Code Patterns

Complete Photo Gallery View

import SwiftUI
import Photos

@MainActor
class PhotoGalleryViewModel: ObservableObject {
    @Published var assets: [PHAsset] = []
    @Published var authorizationStatus: PHAuthorizationStatus = .notDetermined

    func requestAccess() async {
        authorizationStatus = await PHPhotoLibrary.requestAuthorization(for: .readWrite)

        if authorizationStatus == .authorized || authorizationStatus == .limited {
            fetchAssets()
        }
    }

    func fetchAssets() {
        let options = PHFetchOptions()
        options.sortDescriptors = [NSSortDescriptor(key: "creationDate", ascending: false)]
        options.fetchLimit = 100

        let result = PHAsset.fetchAssets(with: .image, options: options)
        assets = result.objects(at: IndexSet(0..<result.count))
    }

    func expandLimitedAccess(from viewController: UIViewController) {
        PHPhotoLibrary.shared().presentLimitedLibraryPicker(from: viewController)
    }
}

 :  {
       viewModel  ()

     body:   {
         {
             viewModel.authorizationStatus {
             .authorized, .limited:
                (assets: viewModel.assets)
             .denied, .restricted:
                ()
             .notDetermined:
                 {
                     {  viewModel.requestAccess() }
                }
             :
                ()
            }
        }
        .task {
             viewModel.requestAccess()
        }
    }
}

---

Resources

Docs: /photosui/phpickerviewcontroller, /photosui/photospicker, /photos/phphotolibrary, /photos/phasset, /photos/phimagemanager

Skills: axiom-photo-library, axiom-camera-capture