Simplify creation of Photos Framework NSURLs in ASMultiplexImageNode

AsyncDisplayKit/ASMultiplexImageNode.h

@@ -9,6 +9,7 @@
 #import <AsyncDisplayKit/ASImageNode.h>
 #import <AsyncDisplayKit/ASImageProtocols.h>
 
+#import <Photos/Photos.h>
 
 @protocol ASMultiplexImageNodeDelegate;
 @protocol ASMultiplexImageNodeDataSource;
@@ -98,6 +99,13 @@ typedef NS_ENUM(NSUInteger, ASMultiplexImageNodeErrorCode) {
  */
 @property (nonatomic, readonly) id displayedImageIdentifier;
 
+/**
+ * @abstract The image manager that this image node should use when requesting images from the Photos framework. Defaults to `PHImageManager.defaultManager`.
+ 
+ * @see `+[NSURL URLWithAssetLocalIdentifier:targetSize:contentMode:options:]` below.
+ */
+@property (nonatomic, strong) PHImageManager *imageManager;
+
 @end
 
 
@@ -195,11 +203,32 @@ didFinishDownloadingImageWithIdentifier:(id)imageIdentifier
  * @abstract An image URL for the specified identifier.
  * @param imageNode The sender.
  * @param imageIdentifier The identifier for the image that will be downloaded.
- * @discussion Supported URLs include assets-library, URLs converted from ASPhotosFrameworkImageRequest, HTTP, HTTPS, and FTP URLs.  If the
+ * @discussion Supported URLs include HTTP, HTTPS, AssetsLibrary, and FTP URLs as well as Photos framework URLs (see note).
- * image is already available to the data source, it should be provided via <[ASMultiplexImageNodeDataSource
+ *
+ * If the image is already available to the data source, it should be provided via <[ASMultiplexImageNodeDataSource
  * multiplexImageNode:imageForImageIdentifier:]> instead.
- * @returns An NSURL for the image identified by `imageIdentifier`, or nil if none is available.
+ * @return An NSURL for the image identified by `imageIdentifier`, or nil if none is available.
+ * @see `+[NSURL URLWithAssetLocalIdentifier:targetSize:contentMode:options:]` below.
  */
 - (NSURL *)multiplexImageNode:(ASMultiplexImageNode *)imageNode URLForImageIdentifier:(id)imageIdentifier;
 
 @end
+
+#pragma mark - 
+
+@interface NSURL (ASPhotosFrameworkURLs)
+
+/**
+ * @abstract Create an NSURL that specifies an image from the Photos framework.
+ *
+ * @discussion When implementing `-multiplexImageNode:URLForImageIdentifier:`, you can return a URL
+ * created by this method and the image node will attempt to load the image from the Photos framework.
+ * @note The `synchronous` flag in `options` is ignored.
+ * @note The `Opportunistic` delivery mode is not supported and will be treated as `HighQualityFormat`.
+ */
++ (NSURL *)URLWithAssetLocalIdentifier:(NSString *)assetLocalIdentifier
+                            targetSize:(CGSize)targetSize
+                           contentMode:(PHImageContentMode)contentMode
+                               options:(PHImageRequestOptions *)options;
+
+@end

AsyncDisplayKit/ASMultiplexImageNode.mm

@@ -157,7 +157,8 @@ typedef void(^ASMultiplexImageLoadCompletionBlock)(UIImage *image, id imageIdent
 
   _cache = cache;
   _downloader = downloader;
-
+  _imageManager = PHImageManager.defaultManager;
+  
   return self;
 }
 
@@ -455,7 +456,7 @@ typedef void(^ASMultiplexImageLoadCompletionBlock)(UIImage *image, id imageIdent
     }];
   }
   // Likewise, if it's a iOS 8 Photo asset, we need to fetch it accordingly.
-  else if (ASPhotosFrameworkImageRequest *request = nextImageURL.asyncdisplaykit_photosRequest) {
+  else if (ASPhotosFrameworkImageRequest *request = [ASPhotosFrameworkImageRequest requestWithURL:nextImageURL]) {
     [self _loadPHAssetWithRequest:request identifier:nextImageIdentifier completion:^(UIImage *image, NSError *error) {
       ASMultiplexImageNodeCLogDebug(@"[%p] Acquired next image (%@) from Photos Framework", weakSelf, nextImageIdentifier);
       finishedLoadingBlock(image, nextImageIdentifier, error);
@@ -529,25 +530,27 @@ typedef void(^ASMultiplexImageLoadCompletionBlock)(UIImage *image, id imageIdent
     
     PHAsset *imageAsset = [assetFetchResult firstObject];
     PHImageRequestOptions *options = [request.options copy];
+    
+    // We don't support opportunistic delivery – one request, one image.
+    if (options.deliveryMode == PHImageRequestOptionsDeliveryModeOpportunistic) {
+      options.deliveryMode = PHImageRequestOptionsDeliveryModeHighQualityFormat;
+    }
+    
     if (options.deliveryMode == PHImageRequestOptionsDeliveryModeHighQualityFormat) {
       // Without this flag the result will be delivered on the main queue, which is pointless
       // But synchronous -> HighQualityFormat so we only use it if high quality format is specified
       options.synchronous = YES;
     }
     
-    [[PHImageManager defaultManager] requestImageForAsset:imageAsset
+    [self.imageManager requestImageForAsset:imageAsset targetSize:request.targetSize contentMode:request.contentMode options:options resultHandler:^(UIImage *image, NSDictionary *info) {
-                                               targetSize:request.targetSize
+      if (NSThread.isMainThread) {
-                                              contentMode:request.contentMode
+        dispatch_async(dispatch_get_global_queue(QOS_CLASS_DEFAULT, 0), ^{
-                                                  options:options
+          completionBlock(image, info[PHImageErrorKey]);
-                                            resultHandler:^(UIImage *image, NSDictionary *info) {
+        });
-                                              if (NSThread.isMainThread) {
+      } else {
-                                                dispatch_async(dispatch_get_global_queue(QOS_CLASS_DEFAULT, 0), ^{
+        completionBlock(image, info[PHImageErrorKey]);
-                                                  completionBlock(image, info[PHImageErrorKey]);
+      }
-                                                });
+    }];
-                                              } else {
-                                                completionBlock(image, info[PHImageErrorKey]);
-                                              }
-                                            }];
   });
 }
 
@@ -648,3 +651,16 @@ typedef void(^ASMultiplexImageLoadCompletionBlock)(UIImage *image, id imageIdent
 }
 
 @end
+
+@implementation NSURL (ASPhotosFrameworkURLs)
+
++ (NSURL *)URLWithAssetLocalIdentifier:(NSString *)assetLocalIdentifier targetSize:(CGSize)targetSize contentMode:(PHImageContentMode)contentMode options:(PHImageRequestOptions *)options
+{
+  ASPhotosFrameworkImageRequest *request = [[ASPhotosFrameworkImageRequest alloc] initWithAssetIdentifier:assetLocalIdentifier];
+  request.options = options;
+  request.contentMode = contentMode;
+  request.targetSize = targetSize;
+  return request.url;
+}
+
+@end

AsyncDisplayKit/Details/ASPhotosFrameworkImageRequest.h

@@ -48,8 +48,6 @@ extern NSString *const ASPhotosURLScheme;
  
  @discussion Some properties of this object are ignored when converting this request into a URL.
  As of iOS SDK 9.0, these properties are `progressHandler` and `synchronous`.
- Note that ASMultiplexImageNode does not support PHImageRequestOptionsDeliveryModeOpportunistic
- because it sends multiple images, and that mode will be replaced by PHImageRequestOptionsDeliveryModeHighQualityFormat
  */
 @property (nonatomic, strong) PHImageRequestOptions *options;
 
@@ -65,13 +63,4 @@ extern NSString *const ASPhotosURLScheme;
 
 @end
 
-@interface NSURL (ASPhotosRequestConverting)
-
-/**
- @abstract A convenience function that calls `[ASPhotosFrameworkImageRequest requestWithURL:self]`.
- */
-- (/*nullable*/ ASPhotosFrameworkImageRequest *)asyncdisplaykit_photosRequest;
-
-@end
-
 // NS_ASSUME_NONNULL_END

AsyncDisplayKit/Details/ASPhotosFrameworkImageRequest.m

@@ -158,12 +158,3 @@ static NSString *const _ASPhotosURLQueryKeyCropHeight = @"crop_h";
 }
 
 @end
-
-@implementation NSURL (ASPhotosRequestConverting)
-
-- (ASPhotosFrameworkImageRequest *)asyncdisplaykit_photosRequest
-{
-  return [ASPhotosFrameworkImageRequest requestWithURL:self];
-}
-
-@end

AsyncDisplayKitTests/ASPhotosFrameworkImageRequestTests.m

@@ -46,7 +46,8 @@ static NSString *const kTestAssetID = @"testAssetID";
 
 - (void)testThatParsingFromURLWorks
 {
-  XCTAssertEqualObjects([self.class urlForExampleImageRequest].asyncdisplaykit_photosRequest, [self.class exampleImageRequest]);
+  NSURL *url = [self.class urlForExampleImageRequest];
+  XCTAssertEqualObjects([ASPhotosFrameworkImageRequest requestWithURL:url], [self.class exampleImageRequest]);
 }
 
 - (void)testThatCopyingWorks