WIP: Migrations

Sources/Setup/Dynamic Models/Dynamic Schema/XcodeDataModelSchema.swift

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+//
+//  XcodeDataModelSchema.swift
+//  CoreStore
+//
+//  Copyright © 2017 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 CoreData
+import Foundation
+
+
+// MARK: - XcodeDataModelSchema
+
+public final class XcodeDataModelSchema: DynamicSchema {
+    
+    public required init(modelVersion: ModelVersion, modelVersionFileURL: URL) {
+        
+        CoreStore.assert(
+            NSManagedObjectModel(contentsOf: modelVersionFileURL) != nil,
+            "Could not find the \"\(modelVersion).mom\" version file for the model at URL \"\(modelVersionFileURL)\"."
+        )
+        
+        self.modelVersion = modelVersion
+        self.modelVersionFileURL = modelVersionFileURL
+    }
+    
+    
+    // MARK: DynamicSchema
+    
+    public let modelVersion: ModelVersion
+    
+    public func rawModel() -> NSManagedObjectModel {
+    
+        if let cachedRawModel = self.cachedRawModel {
+            
+            return cachedRawModel
+        }
+        if let rawModel = NSManagedObjectModel(contentsOf: self.modelVersionFileURL) {
+            
+            self.cachedRawModel = rawModel
+            return rawModel
+        }
+        CoreStore.abort("Could not create an \(cs_typeName(NSManagedObjectModel.self)) from the model at URL \"\(self.modelVersionFileURL)\".")
+    }
+    
+    
+    // MARK: Internal
+    
+    internal let modelVersionFileURL: URL
+    
+    private lazy var rootModelFileURL: URL = cs_lazy { [unowned self] in
+     
+        return self.modelVersionFileURL.deletingLastPathComponent()
+    }
+    
+    
+    // MARK: Private
+    
+    private weak var cachedRawModel: NSManagedObjectModel?
+}