WIP: error handling

Sources/Migrating/SetupResult.swift

@@ -0,0 +1,150 @@
+//
+//  SetupResult.swift
+//  CoreStore
+//
+//  Copyright © 2014 John Rommel Estropia
+//
+//  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
+
+
+// MARK: - SetupResult
+
+/**
+ The `SetupResult` indicates the result of an asynchronous initialization of a persistent store.
+ The `SetupResult` can be treated as a boolean:
+ ```
+ try! CoreStore.addStorage(
+     SQLiteStore(),
+     completion: { (result: SetupResult) -> Void in
+         if result {
+             // succeeded
+         }
+         else {
+             // failed
+         }
+     }
+ )
+ ```
+ or as an `enum`, where the resulting associated object can also be inspected:
+ ```
+ try! CoreStore.addStorage(
+     SQLiteStore(),
+     completion: { (result: SetupResult) -> Void in
+         switch result {
+         case .Success(let storage):
+             // storage is the related StorageInterface instance
+         case .Failure(let error):
+             // error is the CoreStoreError enum value for the failure
+         }
+     }
+ )
+ ```
+ */
+public enum SetupResult<T: StorageInterface>: BooleanType {
+    
+    /**
+     `SetupResult.Success` indicates that the storage setup succeeded. The associated object for this `enum` value is the related `StorageInterface` instance.
+     */
+    case Success(T)
+    
+    /**
+     `SetupResult.Failure` indicates that the storage setup failed. The associated object for this value is the related `CoreStoreError` enum value.
+     */
+    case Failure(CoreStoreError)
+    
+    
+    // MARK: BooleanType
+    
+    public var boolValue: Bool {
+        
+        switch self {
+            
+        case .Success: return true
+        case .Failure: return false
+        }
+    }
+    
+    
+    // MARK: Internal
+    
+    internal init(_ storage: T) {
+        
+        self = .Success(storage)
+    }
+    
+    internal init(_ error: CoreStoreError) {
+        
+        self = .Failure(error)
+    }
+    
+    internal init(_ error: ErrorType) {
+        
+        self = .Failure(CoreStoreError(error))
+    }
+}
+
+
+// MARK: - Deprecated
+
+
+/**
+ Deprecated. Replaced by `SetupResult<T>` when using the new `addStorage(_:completion:)` method variants.
+ */
+@available(*, deprecated=2.0.0, message="Replaced by SetupResult by using the new addStorage(_:completion:) method variants.")
+public enum PersistentStoreResult: BooleanType {
+    
+    /**
+     Deprecated. Replaced by `SetupResult.Success` when using the new `addStorage(_:completion:)` method variants.
+     */
+    case Success(NSPersistentStore)
+    
+    /**
+     Deprecated. Replaced by `SetupResult.Failure` when using the new `addStorage(_:completion:)` method variants.
+     */
+    case Failure(NSError)
+    
+    
+    // MARK: BooleanType
+    
+    public var boolValue: Bool {
+        
+        switch self {
+            
+        case .Success: return true
+        case .Failure: return false
+        }
+    }
+    
+    
+    // MARK: Internal
+    
+    internal init(_ store: NSPersistentStore) {
+        
+        self = .Success(store)
+    }
+    
+    internal init(_ error: NSError) {
+        
+        self = .Failure(error)
+    }
+}