Delete Medium for iOS

ios/Classes/SwiftPhotoGalleryPlugin.swift

@@ -37,6 +37,16 @@ public class SwiftPhotoGalleryPlugin: NSObject, FlutterPlugin {
         }
       )
     }
+    else if(call.method == "deleteMedium") {
+      let arguments = call.arguments as! Dictionary<String, AnyObject>
+      let mediumId = arguments["mediumId"] as! String
+      deleteMedium(
+        mediumId: mediumId,
+        completion: { (success: Bool, error: Error?) -> Void in
+          result(success)
+        }
+      )
+    }
     else if(call.method == "getThumbnail") {
       let arguments = call.arguments as! Dictionary<String, AnyObject>
       let mediumId = arguments["mediumId"] as! String
@@ -222,6 +232,30 @@ public class SwiftPhotoGalleryPlugin: NSObject, FlutterPlugin {
     }
   }
 
+  private func deleteMedium(mediumId: String, completion: @escaping (Bool, Error?) -> Void) {
+      let fetchOptions = PHFetchOptions()
+      if #available(iOS 9, *) {
+        fetchOptions.fetchLimit = 1
+      }
+      let assets: PHFetchResult = PHAsset.fetchAssets(withLocalIdentifiers: [mediumId], options: fetchOptions)
+      
+      if assets.count <= 0 {
+          completion(false, NSError(domain: "photo_gallery", code: 404, userInfo: nil))
+      } else {
+          let asset: PHAsset = assets[0]
+          deleteAssets(assets: [asset]) { success, error in
+              completion(success, error)
+          }
+      }
+  }
+
+  private func deleteAssets(assets: [PHAsset], completion: @escaping (Bool, Error?) -> Void) {
+    PHPhotoLibrary.shared().performChanges({
+        PHAssetChangeRequest.deleteAssets(assets as NSFastEnumeration)
+    }, completionHandler: completion)
+  }
+
+  
   private func getThumbnail(
     mediumId: String,
     width: NSNumber?,
@@ -587,6 +621,7 @@ public class SwiftPhotoGalleryPlugin: NSObject, FlutterPlugin {
     return nil
   }
 
+  
   private func cachePath() -> URL {
     let paths = FileManager.default.urls(for: .cachesDirectory, in: .userDomainMask)
     let cacheFolder = paths[0].appendingPathComponent("photo_gallery")

lib/photo_gallery.dart

@@ -31,7 +31,9 @@ class PhotoGallery {
       'newest': newest,
       'hideIfEmpty': hideIfEmpty,
     });
-    return json.map<Album>((album) => Album.fromJson(album, mediumType, newest)).toList();
+    return json
+        .map<Album>((album) => Album.fromJson(album, mediumType, newest))
+        .toList();
   }
 
   /// List all available media in a specific album, support pagination of media
@@ -62,6 +64,21 @@ class PhotoGallery {
     return Medium.fromJson(json);
   }
 
+  /// Delete medium by medium id
+  static Future<bool> deleteMedium({
+    required String mediumId,
+  }) async {
+    if (!Platform.isIOS) {
+      throw UnsupportedError('This function is only available on iOS');
+    }
+
+    final result = await _channel.invokeMethod('deleteMedium', {
+      'mediumId': mediumId,
+    });
+
+    return result as bool;
+  }
+
   /// Get medium thumbnail by medium id
   static Future<List<int>> getThumbnail({
     required String mediumId,