Un-revert D13513777: Replace ALAssets* with PHPhoto* in RCTCameraRoll

Summary: Replaced all deprecated ALAssets* references to roughly equivalent PHPhoto* references in RCTCameraRoll library. There are still some minor inconsistencies between iOS/Android and documentation that existed prior to this diff that need to be resolved after this.

Reviewed By: fkgozali

Differential Revision: D13593314

fbshipit-source-id: 6d3dc43383e3ad6e3dbe73d4ceceac1ba9261d9d

RCTAssetsLibraryRequestHandler.h

@@ -8,17 +8,8 @@
 #import <React/RCTBridge.h>
 #import <React/RCTURLRequestHandler.h>
 
-@class ALAssetsLibrary;
+@class PHPhotoLibrary;
 
 @interface RCTAssetsLibraryRequestHandler : NSObject <RCTURLRequestHandler>
 
 @end
-
-@interface RCTBridge (RCTAssetsLibraryImageLoader)
-
-/**
- * The shared asset library instance.
- */
-@property (nonatomic, readonly) ALAssetsLibrary *assetsLibrary;
-
-@end

RCTAssetsLibraryRequestHandler.m

@@ -11,41 +11,26 @@
 #import <dlfcn.h>
 #import <objc/runtime.h>
 
-#import <AssetsLibrary/AssetsLibrary.h>
+#import <Photos/Photos.h>
 #import <MobileCoreServices/MobileCoreServices.h>
 
 #import <React/RCTBridge.h>
 #import <React/RCTUtils.h>
 
 @implementation RCTAssetsLibraryRequestHandler
-{
-  ALAssetsLibrary *_assetsLibrary;
-}
 
 RCT_EXPORT_MODULE()
 
-@synthesize bridge = _bridge;
-static Class _ALAssetsLibrary = nil;
-static void ensureAssetsLibLoaded(void)
-{
-  static dispatch_once_t onceToken;
-  dispatch_once(&onceToken, ^{
-    void * handle = dlopen("/System/Library/Frameworks/AssetsLibrary.framework/AssetsLibrary", RTLD_LAZY);
-#pragma unused(handle)
-    _ALAssetsLibrary = objc_getClass("ALAssetsLibrary");
-  });
-}
-- (ALAssetsLibrary *)assetsLibrary
-{
-  ensureAssetsLibLoaded();
-  return _assetsLibrary ?: (_assetsLibrary = [_ALAssetsLibrary new]);
-}
-
 #pragma mark - RCTURLRequestHandler
 
 - (BOOL)canHandleRequest:(NSURLRequest *)request
 {
-  return [request.URL.scheme caseInsensitiveCompare:@"assets-library"] == NSOrderedSame;
+  if (![PHAsset class]) {
+    return NO;
+  }
+
+  return [request.URL.scheme caseInsensitiveCompare:@"assets-library"] == NSOrderedSame
+    || [request.URL.scheme caseInsensitiveCompare:@"ph"] == NSOrderedSame;
 }
 
 - (id)sendRequest:(NSURLRequest *)request
@@ -56,55 +41,72 @@ static void ensureAssetsLibLoaded(void)
     atomic_store(&cancelled, YES);
   };
   
-  [[self assetsLibrary] assetForURL:request.URL resultBlock:^(ALAsset *asset) {
+  if (!request.URL) {
-    if (atomic_load(&cancelled)) {
+    NSString *const msg = [NSString stringWithFormat:@"Cannot send request without URL"];
-      return;
+    [delegate URLRequest:cancellationBlock didCompleteWithError:RCTErrorWithMessage(msg)];
-    }
+    return cancellationBlock;
+  }
   
-    if (asset) {
+  PHFetchResult<PHAsset *> *fetchResult;
  
-      ALAssetRepresentation *representation = [asset defaultRepresentation];
+  if ([request.URL.scheme caseInsensitiveCompare:@"ph"] == NSOrderedSame) {
-      NSInteger length = (NSInteger)representation.size;
+    // Fetch assets using PHAsset localIdentifier (recommended)
-      CFStringRef MIMEType = UTTypeCopyPreferredTagWithClass((__bridge CFStringRef _Nonnull)(representation.UTI), kUTTagClassMIMEType);
+    NSString *const localIdentifier = [request.URL.absoluteString substringFromIndex:@"ph://".length];
+    fetchResult = [PHAsset fetchAssetsWithLocalIdentifiers:@[localIdentifier] options:nil];
+  } else if ([request.URL.scheme caseInsensitiveCompare:@"assets-library"] == NSOrderedSame) {
+    // This is the older, deprecated way of fetching assets from assets-library
+    // using the "assets-library://" protocol
+    fetchResult = [PHAsset fetchAssetsWithALAssetURLs:@[request.URL] options:nil];
+  } else {
+    NSString *const msg = [NSString stringWithFormat:@"Cannot send request with unknown protocol: %@", request.URL];
+    [delegate URLRequest:cancellationBlock didCompleteWithError:RCTErrorWithMessage(msg)];
+    return cancellationBlock;
+  }
   
-      NSURLResponse *response =
+  if (![fetchResult firstObject]) {
-      [[NSURLResponse alloc] initWithURL:request.URL
+    NSString *errorMessage = [NSString stringWithFormat:@"Failed to load asset"
-                                MIMEType:(__bridge NSString *)(MIMEType)
+                              " at URL %@ with no error message.", request.URL];
-                   expectedContentLength:length
+    NSError *error = RCTErrorWithMessage(errorMessage);
-                        textEncodingName:nil];
+    [delegate URLRequest:cancellationBlock didCompleteWithError:error];
+    return cancellationBlock;
+  }
   
-      [delegate URLRequest:cancellationBlock didReceiveResponse:response];
+  if (atomic_load(&cancelled)) {
+    return cancellationBlock;
+  }
 
-      NSError *error = nil;
+  PHAsset *const _Nonnull asset = [fetchResult firstObject];
-      uint8_t *buffer = (uint8_t *)malloc((size_t)length);
-      if ([representation getBytes:buffer
-                        fromOffset:0
-                            length:length
-                             error:&error]) {
 
-        NSData *data = [[NSData alloc] initWithBytesNoCopy:buffer
+  // By default, allow downloading images from iCloud
-                                                    length:length
+  PHImageRequestOptions *const requestOptions = [PHImageRequestOptions new];
-                                              freeWhenDone:YES];
+  requestOptions.networkAccessAllowed = YES;
   
-        [delegate URLRequest:cancellationBlock didReceiveData:data];
+  [[PHImageManager defaultManager] requestImageDataForAsset:asset
-        [delegate URLRequest:cancellationBlock didCompleteWithError:nil];
+                                                    options:requestOptions
-
+                                              resultHandler:^(NSData * _Nullable imageData,
-      } else {
+                                                              NSString * _Nullable dataUTI,
-        free(buffer);
+                                                              UIImageOrientation orientation,
-        [delegate URLRequest:cancellationBlock didCompleteWithError:error];
+                                                              NSDictionary * _Nullable info) {
-      }
+    NSError *const error = [info objectForKey:PHImageErrorKey];
-
+    if (error) {
-    } else {
-      NSString *errorMessage = [NSString stringWithFormat:@"Failed to load asset"
-                                " at URL %@ with no error message.", request.URL];
-      NSError *error = RCTErrorWithMessage(errorMessage);
       [delegate URLRequest:cancellationBlock didCompleteWithError:error];
-    }
-  } failureBlock:^(NSError *loadError) {
-    if (atomic_load(&cancelled)) {
       return;
     }
-    [delegate URLRequest:cancellationBlock didCompleteWithError:loadError];
+
+    NSInteger const length = [imageData length];
+    CFStringRef const dataUTIStringRef = (__bridge CFStringRef _Nonnull)(dataUTI);
+    CFStringRef const mimeType = UTTypeCopyPreferredTagWithClass(dataUTIStringRef, kUTTagClassMIMEType);
+
+    NSURLResponse *const response = [[NSURLResponse alloc] initWithURL:request.URL
+                                                              MIMEType:(__bridge NSString *)(mimeType)
+                                                 expectedContentLength:length
+                                                      textEncodingName:nil];
+    CFRelease(mimeType);
+    
+    [delegate URLRequest:cancellationBlock didReceiveResponse:response];
+    
+    [delegate URLRequest:cancellationBlock didReceiveData:imageData];
+    [delegate URLRequest:cancellationBlock didCompleteWithError:nil];
   }];
   
   return cancellationBlock;
@@ -116,12 +118,3 @@ static void ensureAssetsLibLoaded(void)
 }
 
 @end
-
-@implementation RCTBridge (RCTAssetsLibraryImageLoader)
-
-- (ALAssetsLibrary *)assetsLibrary
-{
-  return [[self moduleForClass:[RCTAssetsLibraryRequestHandler class]] assetsLibrary];
-}
-
-@end

RCTCameraRollManager.h

@@ -5,18 +5,18 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-#import <AssetsLibrary/AssetsLibrary.h>
+#import <Photos/Photos.h>
 
 #import <React/RCTBridgeModule.h>
 #import <React/RCTConvert.h>
 
-@interface RCTConvert (ALAssetGroup)
+@interface RCTConvert (PHFetchOptions)
 
-+ (ALAssetsGroupType)ALAssetsGroupType:(id)json;
++ (PHFetchOptions *)PHFetchOptionsFromMediaType:(NSString *)mediaType;
-+ (ALAssetsFilter *)ALAssetsFilter:(id)json;
 
 @end
 
+
 @interface RCTCameraRollManager : NSObject <RCTBridgeModule>
 
 @end

RCTCameraRollManager.m

@@ -13,6 +13,7 @@
 #import <Photos/Photos.h>
 #import <dlfcn.h>
 #import <objc/runtime.h>
+#import <MobileCoreServices/UTType.h>
 
 #import <React/RCTBridge.h>
 #import <React/RCTConvert.h>
@@ -22,85 +23,46 @@
 
 #import "RCTAssetsLibraryRequestHandler.h"
 
-@implementation RCTConvert (ALAssetGroup)
+@implementation RCTConvert (PHAssetCollectionSubtype)
 
-RCT_ENUM_CONVERTER(ALAssetsGroupType, (@{
+RCT_ENUM_CONVERTER(PHAssetCollectionSubtype, (@{
+   @"album": @(PHAssetCollectionSubtypeAny),
+   @"all": @(PHAssetCollectionSubtypeAny),
+   @"event": @(PHAssetCollectionSubtypeAlbumSyncedEvent),
+   @"faces": @(PHAssetCollectionSubtypeAlbumSyncedFaces),
+   @"library": @(PHAssetCollectionSubtypeSmartAlbumUserLibrary),
+   @"photo-stream": @(PHAssetCollectionSubtypeAlbumMyPhotoStream), // incorrect, but legacy
+   @"photostream": @(PHAssetCollectionSubtypeAlbumMyPhotoStream),
+   @"saved-photos": @(PHAssetCollectionSubtypeAny), // incorrect, but legacy
+   @"savedphotos": @(PHAssetCollectionSubtypeAny), // This was ALAssetsGroupSavedPhotos, seems to have no direct correspondence in PHAssetCollectionSubtype
+}), PHAssetCollectionSubtypeAny, integerValue)
 
-  // New values
-  @"album": @(ALAssetsGroupAlbum),
-  @"all": @(ALAssetsGroupAll),
-  @"event": @(ALAssetsGroupEvent),
-  @"faces": @(ALAssetsGroupFaces),
-  @"library": @(ALAssetsGroupLibrary),
-  @"photo-stream": @(ALAssetsGroupPhotoStream),
-  @"saved-photos": @(ALAssetsGroupSavedPhotos),
 
-  // Legacy values
+@end
-  @"Album": @(ALAssetsGroupAlbum),
-  @"All": @(ALAssetsGroupAll),
-  @"Event": @(ALAssetsGroupEvent),
-  @"Faces": @(ALAssetsGroupFaces),
-  @"Library": @(ALAssetsGroupLibrary),
-  @"PhotoStream": @(ALAssetsGroupPhotoStream),
-  @"SavedPhotos": @(ALAssetsGroupSavedPhotos),
 
-}), ALAssetsGroupSavedPhotos, integerValue)
+@implementation RCTConvert (PHFetchOptions)
 
-static Class _ALAssetsFilter = nil;
++ (PHFetchOptions *)PHFetchOptionsFromMediaType:(NSString *)mediaType
-static NSString *_ALAssetsGroupPropertyName = nil;
-static NSString *_ALAssetPropertyAssetURL = nil;
-static NSString *_ALAssetPropertyLocation = nil;
-static NSString *_ALAssetPropertyDate = nil;
-static NSString *_ALAssetPropertyType = nil;
-static NSString *_ALAssetPropertyDuration = nil;
-static NSString *_ALAssetTypeVideo = nil;
-static NSString *lookupNSString(void * handle, const char * name)
 {
-  void ** sym = dlsym(handle, name);
+  // This is not exhaustive in terms of supported media type predicates; more can be added in the future
-  return (__bridge NSString *)(sym ? *sym : nil);
+  NSString *const lowercase = [mediaType lowercaseString];
-}
-static void ensureAssetsLibLoaded(void)
-{
-  static dispatch_once_t onceToken;
-  dispatch_once(&onceToken, ^{
-    void * handle = dlopen("/System/Library/Frameworks/AssetsLibrary.framework/AssetsLibrary", RTLD_LAZY);
-    RCTAssert(handle != NULL, @"Unable to load AssetsLibrary.framework.");
-    _ALAssetsFilter = objc_getClass("ALAssetsFilter");
-    _ALAssetsGroupPropertyName = lookupNSString(handle, "ALAssetsGroupPropertyName");
-    _ALAssetPropertyAssetURL = lookupNSString(handle, "ALAssetPropertyAssetURL");
-    _ALAssetPropertyLocation = lookupNSString(handle, "ALAssetPropertyLocation");
-    _ALAssetPropertyDate = lookupNSString(handle, "ALAssetPropertyDate");
-    _ALAssetPropertyType = lookupNSString(handle, "ALAssetPropertyType");
-    _ALAssetPropertyDuration = lookupNSString(handle, "ALAssetPropertyDuration");
-    _ALAssetTypeVideo = lookupNSString(handle, "ALAssetTypeVideo");
-  });
-}
 
-+ (ALAssetsFilter *)ALAssetsFilter:(id)json
+  if ([lowercase isEqualToString:@"photos"]) {
-{
+    PHFetchOptions *const options = [PHFetchOptions new];
-  static NSDictionary<NSString *, ALAssetsFilter *> *options;
+    options.predicate = [NSPredicate predicateWithFormat:@"mediaType = %d", PHAssetMediaTypeImage];
-  static dispatch_once_t onceToken;
+    return options;
-  dispatch_once(&onceToken, ^{
+  } else if ([lowercase isEqualToString:@"videos"]) {
-    ensureAssetsLibLoaded();
+    PHFetchOptions *const options = [PHFetchOptions new];
-    options = @{
+    options.predicate = [NSPredicate predicateWithFormat:@"mediaType = %d", PHAssetMediaTypeVideo];
-      // New values
+    return options;
-      @"photos": [_ALAssetsFilter allPhotos],
+  } else {
-      @"videos": [_ALAssetsFilter allVideos],
+    if (![lowercase isEqualToString:@"all"]) {
-      @"all": [_ALAssetsFilter allAssets],
+      RCTLogError(@"Invalid filter option: '%@'. Expected one of 'photos',"
-
+                  "'videos' or 'all'.", mediaType);
-      // Legacy values
+    }
-      @"Photos": [_ALAssetsFilter allPhotos],
+    // This case includes the "all" mediatype
-      @"Videos": [_ALAssetsFilter allVideos],
+    return nil;
-      @"All": [_ALAssetsFilter allAssets],
-    };
-  });
-
-  ALAssetsFilter *filter = options[json ?: @"photos"];
-  if (!filter) {
-    RCTLogError(@"Invalid filter option: '%@'. Expected one of 'photos',"
-                "'videos' or 'all'.", json);
   }
-  return filter ?: [_ALAssetsFilter allPhotos];
 }
 
 @end
@@ -111,43 +73,61 @@ RCT_EXPORT_MODULE()
 
 @synthesize bridge = _bridge;
 
-static NSString *const kErrorUnableToLoad = @"E_UNABLE_TO_LOAD";
 static NSString *const kErrorUnableToSave = @"E_UNABLE_TO_SAVE";
+static NSString *const kErrorUnableToLoad = @"E_UNABLE_TO_LOAD";
 
 RCT_EXPORT_METHOD(saveToCameraRoll:(NSURLRequest *)request
                   type:(NSString *)type
                   resolve:(RCTPromiseResolveBlock)resolve
                   reject:(RCTPromiseRejectBlock)reject)
 {
+  __block PHObjectPlaceholder *placeholder;
+
+  // We load images and videos differently.
+  // Images have many custom loaders which can load images from ALAssetsLibrary URLs, PHPhotoLibrary
+  // URLs, `data:` URIs, etc. Video URLs are passed directly through for now; it may be nice to support
+  // more ways of loading videos in the future.
+  __block NSURL *inputURI = nil;
+  __block UIImage *inputImage = nil;
+
+  void (^saveBlock)(void) = ^void() {
+    // performChanges and the completionHandler are called on
+    // arbitrary threads, not the main thread - this is safe
+    // for now since all JS is queued and executed on a single thread.
+    // We should reevaluate this if that assumption changes.
+    [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
+      PHAssetChangeRequest *changeRequest;
+
+      // Defaults to "photo". `type` is an optional param.
+      if ([type isEqualToString:@"video"]) {
+        changeRequest = [PHAssetChangeRequest creationRequestForAssetFromVideoAtFileURL:inputURI];
+      } else {
+        changeRequest = [PHAssetChangeRequest creationRequestForAssetFromImage:inputImage];
+      }
+
+      placeholder = [changeRequest placeholderForCreatedAsset];
+    } completionHandler:^(BOOL success, NSError * _Nullable error) {
+      if (success) {
+        NSString *uri = [NSString stringWithFormat:@"ph://%@", [placeholder localIdentifier]];
+        resolve(uri);
+      } else {
+        reject(kErrorUnableToSave, nil, error);
+      }
+    }];
+  };
+
   if ([type isEqualToString:@"video"]) {
-    // It's unclear if writeVideoAtPathToSavedPhotosAlbum is thread-safe
+    inputURI = request.URL;
-    dispatch_async(dispatch_get_main_queue(), ^{
+    saveBlock();
-      [self->_bridge.assetsLibrary writeVideoAtPathToSavedPhotosAlbum:request.URL completionBlock:^(NSURL *assetURL, NSError *saveError) {
-        if (saveError) {
-          reject(kErrorUnableToSave, nil, saveError);
-        } else {
-          resolve(assetURL.absoluteString);
-        }
-      }];
-    });
   } else {
-    [_bridge.imageLoader loadImageWithURLRequest:request
+    [_bridge.imageLoader loadImageWithURLRequest:request callback:^(NSError *error, UIImage *image) {
-                                        callback:^(NSError *loadError, UIImage *loadedImage) {
+      if (error) {
-      if (loadError) {
+        reject(kErrorUnableToLoad, nil, error);
-        reject(kErrorUnableToLoad, nil, loadError);
         return;
       }
-      // It's unclear if writeImageToSavedPhotosAlbum is thread-safe
+
-      dispatch_async(dispatch_get_main_queue(), ^{
+      inputImage = image;
-        [self->_bridge.assetsLibrary writeImageToSavedPhotosAlbum:loadedImage.CGImage metadata:nil completionBlock:^(NSURL *assetURL, NSError *saveError) {
+      saveBlock();
-          if (saveError) {
-            RCTLogWarn(@"Error saving cropped image: %@", saveError);
-            reject(kErrorUnableToSave, nil, saveError);
-          } else {
-            resolve(assetURL.absoluteString);
-          }
-        }];
-      });
     }];
   }
 }
@@ -181,89 +161,131 @@ RCT_EXPORT_METHOD(getPhotos:(NSDictionary *)params
 {
   checkPhotoLibraryConfig();
 
-  ensureAssetsLibLoaded();
+  NSUInteger const first = [RCTConvert NSInteger:params[@"first"]];
-  NSUInteger first = [RCTConvert NSInteger:params[@"first"]];
+  NSString *const afterCursor = [RCTConvert NSString:params[@"after"]];
-  NSString *afterCursor = [RCTConvert NSString:params[@"after"]];
+  NSString *const groupName = [RCTConvert NSString:params[@"groupName"]];
-  NSString *groupName = [RCTConvert NSString:params[@"groupName"]];
+  NSString *const groupTypes = [[RCTConvert NSString:params[@"groupTypes"]] lowercaseString];
-  ALAssetsFilter *assetType = [RCTConvert ALAssetsFilter:params[@"assetType"]];
+  NSString *const mediaType = [RCTConvert NSString:params[@"assetType"]];
-  ALAssetsGroupType groupTypes = [RCTConvert ALAssetsGroupType:params[@"groupTypes"]];
+  NSArray<NSString *> *const mimeTypes = [RCTConvert NSStringArray:params[@"mimeTypes"]];
+
+  // If groupTypes is "all", we want to fetch the SmartAlbum "all photos". Otherwise, all
+  // other groupTypes values require the "album" collection type.
+  PHAssetCollectionType const collectionType = ([groupTypes isEqualToString:@"all"]
+                                                ? PHAssetCollectionTypeSmartAlbum
+                                                : PHAssetCollectionTypeAlbum);
+  PHAssetCollectionSubtype const collectionSubtype = [RCTConvert PHAssetCollectionSubtype:groupTypes];
+
+  // Predicate for fetching assets within a collection
+  PHFetchOptions *const assetFetchOptions = [RCTConvert PHFetchOptionsFromMediaType:mediaType];
+  assetFetchOptions.sortDescriptors = @[[NSSortDescriptor sortDescriptorWithKey:@"creationDate" ascending:NO]];
 
   BOOL __block foundAfter = NO;
   BOOL __block hasNextPage = NO;
   BOOL __block resolvedPromise = NO;
   NSMutableArray<NSDictionary<NSString *, id> *> *assets = [NSMutableArray new];
 
-  [_bridge.assetsLibrary enumerateGroupsWithTypes:groupTypes usingBlock:^(ALAssetsGroup *group, BOOL *stopGroups) {
+  // Filter collection name ("group")
-    if (group && (groupName == nil || [groupName isEqualToString:[group valueForProperty:_ALAssetsGroupPropertyName]])) {
+  PHFetchOptions *const collectionFetchOptions = [PHFetchOptions new];
+  collectionFetchOptions.sortDescriptors = @[[NSSortDescriptor sortDescriptorWithKey:@"endDate" ascending:NO]];
+  if (groupName != nil) {
+    collectionFetchOptions.predicate = [NSPredicate predicateWithFormat:[NSString stringWithFormat:@"localizedTitle == '%@'", groupName]];
+  }
 
-      [group setAssetsFilter:assetType];
+  PHFetchResult<PHAssetCollection *> *const assetCollectionFetchResult = [PHAssetCollection fetchAssetCollectionsWithType:collectionType subtype:collectionSubtype options:collectionFetchOptions];
-      [group enumerateAssetsWithOptions:NSEnumerationReverse usingBlock:^(ALAsset *result, NSUInteger index, BOOL *stopAssets) {
+  [assetCollectionFetchResult enumerateObjectsUsingBlock:^(PHAssetCollection * _Nonnull assetCollection, NSUInteger collectionIdx, BOOL * _Nonnull stopCollections) {
-        if (result) {
+    // Enumerate assets within the collection
-          NSString *uri = ((NSURL *)[result valueForProperty:_ALAssetPropertyAssetURL]).absoluteString;
+    PHFetchResult<PHAsset *> *const assetsFetchResult = [PHAsset fetchAssetsInAssetCollection:assetCollection options:assetFetchOptions];
-          if (afterCursor && !foundAfter) {
-            if ([afterCursor isEqualToString:uri]) {
-              foundAfter = YES;
-            }
-            return; // Skip until we get to the first one
-          }
-          if (first == assets.count) {
-            *stopAssets = YES;
-            *stopGroups = YES;
-            hasNextPage = YES;
-            RCTAssert(resolvedPromise == NO, @"Resolved the promise before we finished processing the results.");
-            RCTResolvePromise(resolve, assets, hasNextPage);
-            resolvedPromise = YES;
-            return;
-          }
-          CGSize dimensions = [result defaultRepresentation].dimensions;
-          CLLocation *loc = [result valueForProperty:_ALAssetPropertyLocation];
-          NSDate *date = [result valueForProperty:_ALAssetPropertyDate];
-          NSString *filename = [result defaultRepresentation].filename;
-          int64_t duration = 0;
-          if ([[result valueForProperty:_ALAssetPropertyType] isEqualToString:_ALAssetTypeVideo]) {
-            duration = [[result valueForProperty:_ALAssetPropertyDuration] intValue];
-          }
 
-          [assets addObject:@{
+    [assetsFetchResult enumerateObjectsUsingBlock:^(PHAsset * _Nonnull asset, NSUInteger assetIdx, BOOL * _Nonnull stopAssets) {
-            @"node": @{
+      NSString *const uri = [NSString stringWithFormat:@"ph://%@", [asset localIdentifier]];
-              @"type": [result valueForProperty:_ALAssetPropertyType],
+      if (afterCursor && !foundAfter) {
-              @"group_name": [group valueForProperty:_ALAssetsGroupPropertyName],
+        if ([afterCursor isEqualToString:uri]) {
-              @"image": @{
+          foundAfter = YES;
-                @"uri": uri,
-                @"filename" : filename ?: [NSNull null],
-                @"height": @(dimensions.height),
-                @"width": @(dimensions.width),
-                @"isStored": @YES,
-                @"playableDuration": @(duration),
-              },
-              @"timestamp": @(date.timeIntervalSince1970),
-              @"location": loc ? @{
-                @"latitude": @(loc.coordinate.latitude),
-                @"longitude": @(loc.coordinate.longitude),
-                @"altitude": @(loc.altitude),
-                @"heading": @(loc.course),
-                @"speed": @(loc.speed),
-              } : @{},
-            }
-          }];
         }
-      }];
+        return; // skip until we get to the first one
-    }
+      }
 
-    if (!group) {
+      // Get underlying resources of an asset - this includes files as well as details about edited PHAssets
-      // Sometimes the enumeration continues even if we set stop above, so we guard against resolving the promise
+      if ([mimeTypes count] > 0) {
-      // multiple times here.
+        NSArray<PHAssetResource *> *const assetResources = [PHAssetResource assetResourcesForAsset:asset];
-      if (!resolvedPromise) {
+        if (![assetResources firstObject]) {
+          return;
+        }
+
+        PHAssetResource *const _Nonnull resource = [assetResources firstObject];
+        CFStringRef const uti = (__bridge CFStringRef _Nonnull)(resource.uniformTypeIdentifier);
+        NSString *const mimeType = (NSString *)CFBridgingRelease(UTTypeCopyPreferredTagWithClass(uti, kUTTagClassMIMEType));
+
+        BOOL __block mimeTypeFound = NO;
+        [mimeTypes enumerateObjectsUsingBlock:^(NSString * _Nonnull mimeTypeFilter, NSUInteger idx, BOOL * _Nonnull stop) {
+          if ([mimeType isEqualToString:mimeTypeFilter]) {
+            mimeTypeFound = YES;
+            *stop = YES;
+          }
+        }];
+
+        if (!mimeTypeFound) {
+          return;
+        }
+      }
+
+      // If we've accumulated enough results to resolve a single promise
+      if (first == assets.count) {
+        *stopAssets = YES;
+        *stopCollections = YES;
+        hasNextPage = YES;
+        RCTAssert(resolvedPromise == NO, @"Resolved the promise before we finished processing the results.");
         RCTResolvePromise(resolve, assets, hasNextPage);
         resolvedPromise = YES;
+        return;
       }
-    }
+
-  } failureBlock:^(NSError *error) {
+      NSString *const assetMediaTypeLabel = (asset.mediaType == PHAssetMediaTypeVideo
-    if (error.code != ALAssetsLibraryAccessUserDeniedError) {
+                                             ? @"video"
-      RCTLogError(@"Failure while iterating through asset groups %@", error);
+                                             : (asset.mediaType == PHAssetMediaTypeImage
-    }
+                                                ? @"image"
-    reject(kErrorUnableToLoad, nil, error);
+                                                : (asset.mediaType == PHAssetMediaTypeAudio
+                                                   ? @"audio"
+                                                   : @"unknown")));
+      CLLocation *const loc = asset.location;
+
+      // A note on isStored: in the previous code that used ALAssets, isStored
+      // was always set to YES, probably because iCloud-synced images were never returned (?).
+      // To get the "isStored" information and filename, we would need to actually request the
+      // image data from the image manager. Those operations could get really expensive and
+      // would definitely utilize the disk too much.
+      // Thus, this field is actually not reliable.
+      // Note that Android also does not return the `isStored` field at all.
+      [assets addObject:@{
+        @"node": @{
+          @"type": assetMediaTypeLabel, // TODO: switch to mimeType?
+          @"group_name": [assetCollection localizedTitle],
+          @"image": @{
+              @"uri": uri,
+              @"height": @([asset pixelHeight]),
+              @"width": @([asset pixelWidth]),
+              @"isStored": @YES, // this field doesn't seem to exist on android
+              @"playableDuration": @([asset duration]) // fractional seconds
+          },
+          @"timestamp": @(asset.creationDate.timeIntervalSince1970),
+          @"location": (loc ? @{
+            @"latitude": @(loc.coordinate.latitude),
+            @"longitude": @(loc.coordinate.longitude),
+            @"altitude": @(loc.altitude),
+            @"heading": @(loc.course),
+            @"speed": @(loc.speed), // speed in m/s
+          } : @{})
+        }
+      }];
+    }];
   }];
+
+  // If we get this far and haven't resolved the promise yet, we reached the end of the list of photos
+  if (!resolvedPromise) {
+    hasNextPage = NO;
+    RCTResolvePromise(resolve, assets, hasNextPage);
+    resolvedPromise = YES;
+  }
 }
 
 RCT_EXPORT_METHOD(deletePhotos:(NSArray<NSString *>*)assets