使用 RestKit 将 NSManagedObject 实体映射到自定义类

Posted 2023-03-05

【中文标题】使用 RestKit 将 NSManagedObject 实体映射到自定义类

【英文标题】：Mapping NSManagedObject Entity to custom class with RestKit

【发布时间】：2011-12-11 16:46:45

【问题描述】：

我能够提取 JSON 结果并将它们映射到数据库。但是，一旦我尝试将实体映射到我的子类，我的映射似乎就中断了。

JSON Sample:
"Customers":["Customer":"Active":"Y","BranchID":0,"CustomerID":"SMCJIMB00736253","CustomerIdentifier":"","CustomerTypeID":0,"Name":""]

Setup:
// Initialize RestKit
RKObjectManager* objectManager = [RKObjectManager objectManagerWithBaseURL:TEST_SERVICES_ROOT];

// Initialize object store
objectManager.objectStore = [RKManagedObjectStore objectStoreWithStoreFilename:RKDefaultSeedDatabaseFileName];

Mapping:
RKManagedObjectMapping* customerMapping = [RKManagedObjectMapping mappingForClass:[Customer class]];
customerMapping.primaryKeyAttribute = @"customerID";
[customerMapping mapKeyPathsToAttributes:@"Active", @"active", nil];
[customerMapping mapKeyPathsToAttributes:@"BranchID", @"branchID", nil];
[customerMapping mapKeyPathsToAttributes:@"CustomerID", @"customerID", nil];
[customerMapping mapKeyPathsToAttributes:@"CustomerIdentifier", @"customerIdentifier", nil];
[customerMapping mapKeyPathsToAttributes:@"CustomerTypeID", @"customerTypeID", nil];
[customerMapping mapKeyPathsToAttributes:@"Name", @"name", nil];

Add Mapping:
[objectManager.mappingProvider setMapping:customerMapping forKeyPath:@"Customers.Customer"];

Call WS:
// Load the object model via RestKit    
RKObjectManager* objectManager = [RKObjectManager sharedManager];
NSString *url = [NSString stringWithFormat:SERVICE_CUSTOMERS,@"0",@"1",@"100"];
[objectManager loadObjectsAtResourcePath:url delegate:self block:^(RKObjectLoader* loader) 
    loader.objectMapping = [objectManager.mappingProvider objectMappingForClass:[Customer class]];
];

@interface Customer : NSManagedObject

@property (nonatomic, retain) NSString* active;
@property (nonatomic, retain) NSNumber* branchID;
@property (nonatomic, retain) NSString* customerID;
@property (nonatomic, retain) NSString* customerIdentifier;
@property (nonatomic, retain) NSNumber* customerTypeID;
@property (nonatomic, retain) NSString* name;

//populated via fetch predicate
@property (nonatomic, retain) NSArray* customerAddress;

@end

@implementation Customer

@dynamic active;
@dynamic branchID;
@dynamic customerID;
@dynamic customerIdentifier;
@dynamic customerTypeID;
@dynamic name;

//populated via fetch predicate
@dynamic customerAddress;

@end

只要我不尝试将 Customer 类映射到数据模型中的实体，它就可以正常工作。最终，我试图将我的 Customer 类用作 MKAnnotation，但我不能，因为我无法提供具体的实现类。我敢肯定对 RestKit 存在某种误解。我看到 RKTwitterCoreData 将 RKStatus 作为具体的子类。

@结束

【参考方案1】：

好的， 经过多次试验和错误，我想通了！问题是我需要在我的映射上设置我的 rootKeyPath 以匹配我在将映射添加到映射提供程序时使用的 rootkeyPath。 RKTwitterCoreData 客户端不这样做，但无论出于何种原因我都需要这样做。

    RKManagedObjectMapping* userMapping = [RKManagedObjectMapping mappingForClass:[User class]];
    userMapping.rootKeyPath = @"User";
    userMapping.primaryKeyAttribute = @"userName";
    [userMapping mapKeyPathsToAttributes:@"Authenticated", @"authenticated", nil];

    ................
    [objectManager.mappingProvider setMapping:userMapping forKeyPath:@"User"];