Swift 2016-01-05 15:47
CoreValue
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CoreValue是Core Data的轻量级封装框架。它也包含了一些简单的抽象，便于查询，更新，保存和删除。
- 继承类
01 | struct Shop: CVManagedPersistentStruct { |
02 |
03 | // The name of the CoreData entity |
04 | static let EntityName = "Shop" |
05 |
06 | // The ObjectID of the CoreData object we saved to or loaded from |
07 | var objectID: NSManagedObjectID? |
08 |
09 | // Our properties |
10 | let name: String |
11 | var age: Int32 |
12 | var owner: Owner? |
13 |
14 | // Create a Value Type from a NSManagedObject |
15 | // If this looks too complex, see below for an explanation and alternatives |
16 | static func fromObject(o: NSManagedObject) -> Unboxed<Shop> { |
17 | return curry(self.init) |
18 | <^> o <|? "objectID" |
19 | <*> o <| "name" |
20 | <*> o <| "age" |
21 | <*> o <|? "owner" |
22 | } |
23 | } |
- 创建、保存、删除
01 | // Get all shops (`[Shop]` is required for the type checker to get your intent!) |
02 | let shops: [Shop] = Shop.query(self.context, predicate: nil) |
03 |
04 | // Create a shop |
05 | let aShop = Shop(name: "Household Wares", age: 30, owner: nil) |
06 |
07 | // Store it as a managed object |
08 | aShop.save(self.context) |
09 |
10 | // Change the age |
11 | aShop.age = 40 |
12 |
13 | // Update the managed object in the store |
14 | aShop.save(self.context) |
15 |
16 | // Delete the object |
17 | aShop.delete(self.context) |
18 |
19 | // Convert a managed object into a shop (see below) |
20 | let nsShop: Shop? = Shop.fromObject(aNSManagedObject).value |
21 |
22 | // Convert a shop into an nsmanagedobject |
23 | let shopObj = nsShop.mutatingToObject(self.context) |
- 查询
1 | // With Sort Descriptors |
2 | public static func query(context: NSManagedObjectContext, predicate: NSPredicate?, sortDescriptors: Array<NSSortDescriptor>) -> Array |
3 |
4 | // Without sort descriptors |
5 | public static func query(context: NSManagedObjectContext, predicate: NSPredicate?) -> Array |