RestKit 0.20 映射问题
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【中文标题】RestKit 0.20 映射问题【英文标题】:RestKit 0.20 Mapping problems 【发布时间】:2012-12-21 15:50:36 【问题描述】:我在发出请求并尝试将响应放入 Core Data 时收到以下错误。
Performing managed object mapping with a nil managed object cache:
Unable to update existing object instances by identification attributes. Duplicate objects may be created.
我设置了 identifactionAttributes 并使用对象管理器来配置请求操作。而且我仍然收到“无法更新现有对象实例...”
objectMapping = [RKEntityMapping mappingForEntityForName:@"Entity" inManagedObjectStore:self.managedObjectStore];
objectMapping.identificationAttributes = @[ @"route_id" ];
[objectMapping addAttributeMappingsFromDictionary:@
@"point_alt" : @"point_alt",
@"point_lat" : @"point_lat",
@"point_long" : @"point_long",
@"location_id" : @"location_id",
@"route_id" : @"route_id"
];
NSMutableURLRequest *request = [[RKObjectManager sharedManager] requestWithObject:nil method:RKRequestMethodPOST path:path parameters:paramsWithEncr];
RKManagedObjectRequestOperation *operation = [[RKObjectManager sharedManager] managedObjectRequestOperationWithRequest:request managedObjectContext:self.managedObjectStore.mainQueueManagedObjectContext success:^(RKObjectRequestOperation *operation, RKMappingResult *result)
NSLog(@"Loading mapping result: %d", result.count);
failure:^(RKObjectRequestOperation *operation, NSError *error)
NSLog(@"Fail!");
];
【问题讨论】:
您收到的消息只是一个警告。你只是想摆脱警告吗?还是你有一些更大的问题?好像根本没有对象存储在数据库中? 数据库中没有存储对象... 【参考方案1】:我没有配置核心数据与对象管理器的集成。如果你有同样的问题,你应该这样做:
NSManagedObjectModel *managedObjectModel = [NSManagedObjectModel mergedModelFromBundles:nil];
RKManagedObjectStore *managedObjectStore = [[RKManagedObjectStore alloc] initWithManagedObjectModel:managedObjectModel];
NSString *path = [RKApplicationDataDirectory() stringByAppendingPathComponent:@"Store.sqlite"];
[managedObjectStore addSQLitePersistentStoreAtPath:path fromSeedDatabaseAtPath:nil withConfiguration:nil options:nil error:nil];
[managedObjectStore createManagedObjectContexts];
【讨论】:
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