CoreStore/Sources/ObjectRepresentation.swift

//
//  ObjectRepresentation.swift
//  CoreStore
//
//  Copyright © 2018 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


// MARK - ObjectRepresentation

/**
 An object that acts as interfaces for `CoreStoreObject`s or `NSManagedObject`s
 */
public protocol ObjectRepresentation {
    
    /**
     The object type represented by this protocol
     */
    associatedtype ObjectType: DynamicObject
    
    /**
     Used internally by CoreStore. Do not call directly.
     */
    static func cs_fromRaw(object: NSManagedObject) -> Self
    
    /**
     Used internally by CoreStore. Do not call directly.
     */
    func cs_id() -> ObjectType.ObjectID
    
    /**
     Used internally by CoreStore. Do not call directly.
     */
    func cs_object() -> ObjectType?
    
    /**
     Used internally by CoreStore. Do not call directly.
     */
    func cs_rawObject(in context: NSManagedObjectContext) -> NSManagedObject?
}

extension NSManagedObject: ObjectRepresentation {}

extension CoreStoreObject: ObjectRepresentation {}

extension DynamicObject where Self: ObjectRepresentation {
    
    public func cs_object() -> Self? {
        
        return self
    }
    
    public func cs_rawObject(in context: NSManagedObjectContext) -> NSManagedObject? {
        
        return context.fetchExisting(self.cs_id())
    }
}