added NSManagedContext extension

Author: Philipp Homann

Sources/CoreUsefulSDK/Extensions/NSManagedObjectContext+Utils.swift

@@ -0,0 +1,64 @@
+//
+//  NSManagedObjectContext+Utils.swift
+//  DigitalAssortmentPlanner
+//
+//  Created by Philipp Homann on 27.10.20.
+//  Copyright © 2020 On Running. All rights reserved.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+
+import Foundation
+
+import CoreData
+
+public extension NSManagedObjectContext {
+    @discardableResult func saveIfNeeded(shouldReset : Bool = false) throws -> Bool {
+        if self.hasChanges {
+            try self.save()
+            if shouldReset == true {
+                self.reset() // Reset the context to clean up the cache and low the memory footprint.
+            }
+            return true
+        } else {
+            return false
+        }
+    }
+}
+
+
+/// allows you to use performAndWait with a throwing function in closure
+/// usage:  try context.performAndWait { }
+public extension NSManagedObjectContext {
+    func performAndWait<T>(_ block: () throws -> T) throws -> T {
+        var result: Result<T, Error>?
+        performAndWait {
+            result = Result { try block() }
+        }
+        return try result!.get()
+    }
+
+    func performAndWait<T>(_ block: () -> T) -> T {
+        var result: T?
+        performAndWait {
+            result = block()
+        }
+        return result!
+    }
+}