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Mantle makes it easy to write a simple model layer for your Cocoa or Cocoa Touch application. Mantle can still be a convenient translation layer between the API and your managed model objects.
本文使用mantle作data model，并使用其对coredata的interface创建数据持久化的过程。
操作过程很简单，就是数据的转换：
1.Manle data model
Mantle中用于持久化的方法：
// A MTLModel object that supports being serialized to and from Core Data as an
// NSManagedObject.
- @protocol MTLManagedObjectSerializing
- @required
// The name of the Core Data entity that the receiver serializes to and
// deserializes from.
- + (NSString *)managedObjectEntityName;
// Specifies how to map property keys to different keys on the receiver's
// +managedObjectEntity.
- + (NSDictionary *)managedObjectKeysByPropertyKey;
.h 文件 [objc] view plaincopyprint? 
- #import
-
- @interface BannerWrapper : MTLModel
-
- @property (nonatomic, readonly) bool result;
- @property (copy, nonatomic, readonly) NSNumber *resultId;
- @property (copy, nonatomic, readonly) NSString *resultMsg;
- @property (copy, nonatomic) NSArray *bannerList;
- +(NSSortDescriptor *)sortDescriptor;
- @end
-
- @interface Banner : MTLModel
-
- @property (copy, nonatomic, readonly) NSNumber *bannerId;
- @property (copy, nonatomic, readonly) NSString *picUrl;
- @property (copy, nonatomic, readonly) NSString *toDetailUrl;
- @property (copy, nonatomic, readonly) NSNumber *width;
- @property (copy, nonatomic, readonly) NSNumber *height;
-
- @end
.m文件 [objc] view plaincopyprint?
- #import "Banner.h"
-
- @implementation BannerWrapper
-
- #pragma mark - JSON serialization
-
- + (NSDictionary *)JSONKeyPathsByPropertyKey {
- return @{
- @"result" : @"result",
- @"resultId" : @"resultId",
- @"resultMsg" : @"resultMSG",
- @"bannerList" : @"banner"
- };
- }
-
- + (NSValueTransformer *)bannerListJSONTransformer
- {
- return [NSValueTransformer mtl_JSONArrayTransformerWithModelClass:[Banner class]];
- }
-
- #pragma mark - Managed object serialization
-
- + (NSString *)managedObjectEntityName {
- return @"BannerWrapper";
- }
-
- + (NSDictionary *)managedObjectKeysByPropertyKey {
- return nil;
- }
-
- +(NSDictionary *)relationshipModelClassesByPropertyKey{
- return @{
- @"bannerList" : [Banner class],
- };
- }
-
- //在从coredata中取数据时的数据排序方式
- +(NSSortDescriptor *)sortDescriptor{
- return [[NSSortDescriptor alloc] initWithKey:@"resultId" ascending:YES];
- }
-
- @end
-
- @implementation Banner
-
- #pragma mark - JSON serialization
-
- + (NSDictionary *)JSONKeyPathsByPropertyKey {
- return @{
- @"bannerId" : @"id",
- @"picUrl" : @"picUrl",
- @"toDetailUrl" : @"toDetailUrl",
- @"width":@"width",
- @"height":@"height"
- };
- }
-
- #pragma mark - Managed object serialization
-
- + (NSString *)managedObjectEntityName {
- return @"Banner";
- }
-
- + (NSDictionary *)managedObjectKeysByPropertyKey {
- return nil;
- }
-
- @end
2.coredata 持久化类 Coredata主要元素简要介绍 网上有很多图，但，还是觉得一本书上的这个图最好： 
- 1， Managed Object Model
Managed Object Model 是描述应用程序的数据模型，这个模型包含实体（Entity），特性（Property），读取请求（Fetch Request）等。（下文都使用英文术语。）
2，Managed Object Context
Managed Object Context 参与对数据对象进行各种操作的全过程，并监测数据对象的变化，以提供对 undo/redo 的支持及更新绑定到数据的 UI。
3，Persistent Store Coordinator
Persistent Store Coordinator 相当于数据文件管理器，处理底层的对数据文件的读取与写入。一般我们无需与它打交道。
4，Managed Object
Managed Object 数据对象，与 Managed Object Context 相关联。
-
5，Controller
图中绿色的 Array Controller, Object Controller, Tree Controller 这些控制器，一般都是通过 control+drag 将 Managed Object Context 绑定到它们，这样我们就可以 |