Added functions to fetch only one entity

Sources/CoreDataWrapper/CoreDataWrapper+AsyncOperations.swift

@@ -276,6 +276,80 @@ extension CoreDataWrapper {
  operationBlock()
  }
  }
+ // MARK: - Fetch one entity
+ final public func fetchOneOf<M: NSManagedObject>
+ (type: M.Type,
+ context: NSManagedObjectContext? = nil,
+ predicate: NSPredicate? = nil,
+ sortBy: [String: Bool]?,
+ isBlocking: Bool = false,
+ completion: @escaping (M?) -> Void,
+ completionOnMainThread: Bool) {
+
+ var innerContext: NSManagedObjectContext
+ if let context = context {
+ innerContext = context
+ } else {
+ innerContext = self.mainContext
+ if isBlocking {
+ assertionFailure("Please use Sync operation if want blocking operation on main context")
+ }
+ }
+ let sortByBlock = { () -> [NSSortDescriptor] in
+ var sortDescriptors = [NSSortDescriptor]()
+ guard let sortBy = sortBy else {
+ return sortDescriptors
+ }
+ for (key, sortOrder) in sortBy {
+ sortDescriptors.append(NSSortDescriptor(key: key, ascending: sortOrder))
+ }
+ return sortDescriptors
+ }
+ let operationBlock = {
+ let request = NSFetchRequest<M>.init(entityName: String(describing: type))
+ request.predicate = predicate
+ request.sortDescriptors = sortByBlock()
+ request.returnsObjectsAsFaults = false
+ request.fetchLimit = 1
+ let fetched = try? innerContext.fetch(request)
+
+ let mainCaller = {
+ self.mainContext.perform {
+ if let fetched = fetched {
+ var allObjects = [M]()
+ for fetchedObj in fetched {
+ if let existing = try? self.mainContext.existingObject(with: fetchedObj.objectID) as? M {
+ allObjects.append(existing)
+ }
+ }
+ completion(allObjects.first)
+ } else {
+ completion(nil)
+ }
+ }
+ }
+ let bgCaller = {
+ completion(fetched?.first)
+ }
+ let tuple = (completionOnMainThread, (context != nil))
+ switch tuple {
+ case (false, false): //It's main context and no main thread callback
+ bgCaller()
+ case (false, true): //It's bg context and no main thread callback
+ bgCaller()
+ case (true, false): //It's main context and main thread callback
+ bgCaller()
+ case (true, true): //It's bg context and main thread callback
+ mainCaller()
+ }
+ }
+ isBlocking ?
+ innerContext.performAndWait {
+ operationBlock()
+ }: innerContext.perform {
+ operationBlock()
+ }
+ }
  // MARK: - Fetch Properties
  final public func fetchPropertiesAsyncOf<M: NSManagedObject>
  (type: M.Type,

Sources/CoreDataWrapper/CoreDataWrapper+SyncOperations.swift

@@ -101,6 +101,35 @@ extension CoreDataWrapper {
  }
  return fetched
  }
+ // MARK: - Fetch one entity
+ final public func fetchOneOf<M: NSManagedObject>
+ (type: M.Type,
+ predicate: NSPredicate? = nil,
+ sortBy: [String: Bool]? = nil) -> M? {
+ var fetched: M?
+ self.mainContext.performAndWait {
+ let sortByBlock = { () -> [NSSortDescriptor] in
+ var sortDescriptors = [NSSortDescriptor]()
+ guard let sortBy = sortBy else {
+ return sortDescriptors
+ }
+ for (key, sortOrder) in sortBy {
+ sortDescriptors.append(NSSortDescriptor(key: key, ascending: sortOrder))
+ }
+ return sortDescriptors
+ }
+ guard let entityName = type.entity().name else {
+ return
+ }
+ let request = NSFetchRequest<M>.init(entityName: entityName)
+ request.predicate = predicate
+ request.fetchLimit = 1
+ request.sortDescriptors = sortByBlock()
+ request.returnsObjectsAsFaults = false
+ fetched = try? self.mainContext.fetch(request).first
+ }
+ return fetched
+ }
  // MARK: - Fetch Properties
  final public func fetchPropertiesOf<M: NSManagedObject>
  (type: M.Type,