Question

我在我的应用程序中使用RestKit 0.20.3。它具有离线模式，因此我必须将对象存储在本地coredata中。

每当从服务器删除某些对象时，它会在JSON中发送deleted = true属性，我在deletionPredicate的映射中处理该属性。这是我的映射。

- (RKEntityMapping *)meetingsMapping {

    RKEntityMapping *meetingsMapping = [RKEntityMapping mappingForEntityForName:@"DBMeetings" inManagedObjectStore:objectManager.managedObjectStore];
    meetingsMapping.setDefaultValueForMissingAttributes = NO;
    meetingsMapping.deletionPredicate = [NSPredicate predicateWithFormat:@"shouldBeDeleted = 1"];
    [meetingsMapping setModificationAttributeForName:@"updated_at"];
    meetingsMapping.identificationAttributes = @[@"id"];

    [meetingsMapping addAttributeMappingsFromDictionary:@{
                                                      @"id": @"id",
                                                      @"title": @"title",

                                                      @"start_date_human": @"start_date_human",
                                                      @"start_time_human": @"start_time_human",
                                                      @"finish_date_human": @"finish_date_human",
                                                      @"finish_time_human": @"finish_time_human",

                                                      @"lock": @"lock",
                                                      @"location": @"location",
                                                      @"sample": @"sample",

                                                      @"deleted": @"shouldBeDeleted",

                                                      @"created_at": @"created_at",
                                                      @"updated_at": @"updated_at",
                                                      @"follow_up_id": @"follow_up_id",
                                                      @"total_topics": @"total_topics",
                                                      }];

[meetingsMapping addRelationshipMappingWithSourceKeyPath:@"tags" mapping:[self tagsMapping]];
[meetingsMapping addRelationshipMappingWithSourceKeyPath:@"required_participants" mapping:[self contactsMapping]];
[meetingsMapping addRelationshipMappingWithSourceKeyPath:@"optional_participants" mapping:[self contactsMapping]];
[meetingsMapping addRelationshipMappingWithSourceKeyPath:@"readonly_participants" mapping:[self contactsMapping]];
[meetingsMapping addRelationshipMappingWithSourceKeyPath:@"organizer" mapping:[self contactsMapping]];

return meetingsMapping;

}

它运行良好，属性从本地CoreData中删除。

问题是方法getObjectsAtPath仍然返回mappingResult参数中的所有对象。

[[RKObjectManager sharedManager] getObjectsAtPath:[NSString stringWithFormat:@"%@?type=past&page=%i", URL_MEETINGS, pageNo]
                                       parameters:nil
                                          success:^(RKObjectRequestOperation *operation, RKMappingResult *mappingResult) {
                                              KLog(@"%@", mappingResult.array); // It is returning all objects, not only non-deleted objects 
                                              completionHandler(mappingResult.array, nil);
                                          }
                                          failure:^(RKObjectRequestOperation *operation, NSError *error) {
                                              completionHandler(nil, error);
                                          }];

假设如果删除了20个对象中的5个，mappingResult.array返回20个记录而不是15个.5个已删除的记录没有数据。当我记录mappingResult.array时，前5条记录打印如下：

2014-03-27 13:10:14.105 MeetingKing[7851:70b] W restkit.network.core_data:RKManagedObjectRequestOperation.m:125 Unable to refetch managed object <DBMeetings: 0xc1cb820> (entity: DBMeetings; id: 0xc1a6a60 <x-coredata://7B9FC7F6-C0E9-4DF5-91AC-D7C49F54B4F5/DBMeetings/t2915CF2E-2D7D-4E29-8B39-B1C51151809410> ; data: <fault>): the object has a temporary managed object ID.
2014-03-27 13:10:14.105 MeetingKing[7851:70b] W restkit.network.core_data:RKManagedObjectRequestOperation.m:125 Unable to refetch managed object <DBMeetings: 0xc5b2ed0> (entity: DBMeetings; id: 0xc5d1110 <x-coredata://7B9FC7F6-C0E9-4DF5-91AC-D7C49F54B4F5/DBMeetings/t2915CF2E-2D7D-4E29-8B39-B1C51151809416> ; data: <fault>): the object has a temporary managed object ID.
2014-03-27 13:10:14.106 MeetingKing[7851:70b] W restkit.network.core_data:RKManagedObjectRequestOperation.m:125 Unable to refetch managed object <DBMeetings: 0xc58b6a0> (entity: DBMeetings; id: 0xc5d3de0 <x-coredata://7B9FC7F6-C0E9-4DF5-91AC-D7C49F54B4F5/DBMeetings/t2915CF2E-2D7D-4E29-8B39-B1C51151809417> ; data: <fault>): the object has a temporary managed object ID.
2014-03-27 13:10:14.106 MeetingKing[7851:70b] W restkit.network.core_data:RKManagedObjectRequestOperation.m:125 Unable to refetch managed object <DBMeetings: 0xc5b50e0> (entity: DBMeetings; id: 0xc5d4af0 <x-coredata://7B9FC7F6-C0E9-4DF5-91AC-D7C49F54B4F5/DBMeetings/t2915CF2E-2D7D-4E29-8B39-B1C51151809419> ; data: <fault>): the object has a temporary managed object ID.
2014-03-27 13:10:14.107 MeetingKing[7851:70b] W restkit.network.core_data:RKManagedObjectRequestOperation.m:125 Unable to refetch managed object <DBMeetings: 0xc1ed5a0> (entity: DBMeetings; id: 0xc1c84e0 <x-coredata://7B9FC7F6-C0E9-4DF5-91AC-D7C49F54B4F5/DBMeetings/t2915CF2E-2D7D-4E29-8B39-B1C51151809422> ; data: <fault>): the object has a temporary managed object ID.

如果我签入DB，则只有15条记录。没关系。

如果我从DB显式提取，它只返回15条记录，那就没问题

但在getObjectsAtPath回调中，mappingResult.array参数返回20条记录。那不行。：（

问题是count的{{1}}变为20，我的mappingResult.array显示20行，其中5行没有数据。

RestKit是否还有其他回调准确返回15条记录，以便我不必显式从DB中获取记录？

Answer 1

mappingResult正在返回已映射的对象，这就是它应该做的事情。随后删除某些项目的事实并没有改变这一点 - 事实上，您知道所有需要的信息，因为您知道所有已映射的对象以及哪些对象已被删除。

简单的解决方案是使用NSFetchedResultsController为您的表格视图提供数据。它将正确处理更新，插入和删除，您无需再做其他工作。

或者，您需要迭代mappingResult.array并过滤掉已删除的项目。验证的最佳方法是使用支票：

if (item.isDeleted || item.managedObjectContext == nil) {
    // remove the now invalid item...
}

RestKit本地删除对象，仍然出现在映射中

1 个答案: