MagicalRecord 调用多个保存方法

Posted 2023-03-04

【中文标题】MagicalRecord 调用多个保存方法

【英文标题】：MagicalRecord call multiple save methods

【发布时间】：2015-05-27 14:19:48

【问题描述】：

我是 MagicalRecord 的新手。我从不同的方法更新相同的实体时遇到问题。这是我的例子：我有一些从网络服务获得的广告。完成后，如果有任何将它们的活动属性设置为 0，我需要更新数据库中的广告。立即，我需要调用保存我的广告的函数或只更新它们。之后，我需要删除所有过期的广告，然后删除不活动的广告。这些广告实际上是基于语言的，所以每次我更改应用程序的语言时，一些广告就会变得无效。它需要是这样的。这是我的保存和删除代码：

- (void) saveBanners:(NSDictionary *)activeBanner

      NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
     [formatter setDateFormat:@"yyyy-MM-dd'T'HH:mm:ss"];

if (activeBanner != nil || [activeBanner count] != 0)

    for (int i = 0; i<[activeBanner.banners count]; i++)
    
        NSDate *dateTo = [formatter dateFromString:[activeBanner.banners[i] DateValidTo]];
        NSDate *dateFrom = [formatter dateFromString:[activeBanner.banners[i] DateValidFrom]];
        NSLog(@"%@ %@", dateTo, [activeBanner.banners[i] DateValidTo]);

        [MagicalRecord
         saveWithBlock:^(NSManagedObjectContext *localContext)
         
             Banner *banner = [Banner MR_findFirstByAttribute:@"serverId" withValue:[activeBanner.banners[i] ID] inContext:localContext];
             Banner *localBanner;
             if (banner != nil)
             
                 localBanner = [banner MR_inContext:localContext];
             
             else
             
                 localBanner = [Banner MR_createInContext:localContext];
             

             localBanner.serverId = [activeBanner.banners[i] ID];
             localBanner.name = [activeBanner.banners[i] Name];
             localBanner.text = [activeBanner.banners[i] BannerText];
             localBanner.dateFrom = dateFrom;
             localBanner.dateTo = dateTo;
             localBanner.image = [activeBanner.banners[i] ImageData];
             localBanner.active = [NSNumber numberWithBool:YES];
             localBanner.country = [activeBanner.banners[i] CountryCode];
         ];
    



- (void)setBannerInactive:(NSString *)country


NSPredicate *bannerFilter = [NSPredicate predicateWithFormat:@"country IN %@", @[[country uppercaseString]]]; // paziti na upperCase, tako vraca u bazi
NSArray *banners = [Banner MR_findAllWithPredicate:bannerFilter];
NSNumber *bannersCount = [Banner MR_numberOfEntitiesWithPredicate:bannerFilter];

if (bannersCount.integerValue != 0)

    for (int i = 0; i < bannersCount.integerValue; i++)
    

        [MagicalRecord saveWithBlock:^(NSManagedObjectContext *localContext)
         
             Banner *banner = [Banner MR_findFirstByAttribute:@"serverId" withValue:[banners[i] serverId] inContext:localContext];

             if (banner != nil)
             
                 Banner *localBanner = [banner MR_inContext:localContext];
                 localBanner.active = [NSNumber numberWithBool:NO];
             
          completion:^(BOOL success, NSError *error) 
             NSLog(@"I am here");
         ];
    



- (void)deleteInactiveBanners


NSPredicate *inactiveBannerFilter = [NSPredicate predicateWithFormat:@"active = NO"]; // NO = neaktivni
NSArray *banners = [Banner MR_findAllWithPredicate:inactiveBannerFilter];

if (banners != nil || [banners count] != 0)

    for (int i = 0; i < [banners count]; i++)
    
        Banner *banner = banners[i];

        if (banner != nil)
        
            [MagicalRecord saveWithBlock:^(NSManagedObjectContext *localContext)
             
                 Banner *localBanner = [banner MR_inContext:localContext];
                 [localBanner MR_deleteEntity];
             ];
        
    

我在我的视图控制器中从我的视图模型中调用它们，在我的 RAC 信号的完整块中获取我的广告：

 [self.viewModel setBannerInactive:appLanguage];

     if (self.viewModel.activeBanner != nil)
     
         [self.viewModel saveBanner:self.splashViewModel.activeBanner];
     

     [self.viewModel deleteInactiveBanners];

我知道 saveWithBlocks 是在后台线程中执行的。问题是当我调用 setBannerInactive 时，它​​在调用 saveBanners 时并未完成，因此一切都无法正常工作。如何使用 MagicalRecord 正确调用这些方法。我使用的是最新的 2.x MagicalRecord，而不是 v3。？

【参考方案1】：

类似的东西（我没有尝试也没有尝试编译它，所以它可能包含错误但想法就在那里）

- (void) saveBanners:(NSDictionary *)activeBanner withCompletion:(void(^)())completionBlock

      NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
     [formatter setDateFormat:@"yyyy-MM-dd'T'HH:mm:ss"];

if (activeBanner != nil || [activeBanner count] != 0)

    for (int i = 0; i<[activeBanner.banners count]; i++)
    
        NSDate *dateTo = [formatter dateFromString:[activeBanner.banners[i] DateValidTo]];
        NSDate *dateFrom = [formatter dateFromString:[activeBanner.banners[i] DateValidFrom]];
        NSLog(@"%@ %@", dateTo, [activeBanner.banners[i] DateValidTo]);

        [MagicalRecord
         saveWithBlock:^(NSManagedObjectContext *localContext)
         
             Banner *banner = [Banner MR_findFirstByAttribute:@"serverId" withValue:[activeBanner.banners[i] ID] inContext:localContext];
             Banner *localBanner;
             if (banner != nil)
             
                 localBanner = [banner MR_inContext:localContext];
             
             else
             
                 localBanner = [Banner MR_createInContext:localContext];
             

             localBanner.serverId = [activeBanner.banners[i] ID];
             localBanner.name = [activeBanner.banners[i] Name];
             localBanner.text = [activeBanner.banners[i] BannerText];
             localBanner.dateFrom = dateFrom;
             localBanner.dateTo = dateTo;
             localBanner.image = [activeBanner.banners[i] ImageData];
             localBanner.active = [NSNumber numberWithBool:YES];
             localBanner.country = [activeBanner.banners[i] CountryCode];
          completion:^(BOOL success, NSError *error) 
if(completionBlock)
completionBlock();
             NSLog(@"I am here");
         ];
    



- (void)setBannerInactive:(NSString *)country withCompletion:(void(^)())completionBlock


NSPredicate *bannerFilter = [NSPredicate predicateWithFormat:@"country IN %@", @[[country uppercaseString]]]; // paziti na upperCase, tako vraca u bazi
NSArray *banners = [Banner MR_findAllWithPredicate:bannerFilter];
NSNumber *bannersCount = [Banner MR_numberOfEntitiesWithPredicate:bannerFilter];

if (bannersCount.integerValue != 0)

    for (int i = 0; i < bannersCount.integerValue; i++)
    

        [MagicalRecord saveWithBlock:^(NSManagedObjectContext *localContext)
         
             Banner *banner = [Banner MR_findFirstByAttribute:@"serverId" withValue:[banners[i] serverId] inContext:localContext];

             if (banner != nil)
             
                 Banner *localBanner = [banner MR_inContext:localContext];
                 localBanner.active = [NSNumber numberWithBool:NO];
             
          completion:^(BOOL success, NSError *error) 
             NSLog(@"I am here");
if(completionBlock)
completionBlock();
         ];
    



- (void)deleteInactiveBanners withCompletion:(void(^)())completionBlock


NSPredicate *inactiveBannerFilter = [NSPredicate predicateWithFormat:@"active = NO"]; // NO = neaktivni
NSArray *banners = [Banner MR_findAllWithPredicate:inactiveBannerFilter];

if (banners != nil || [banners count] != 0)

    for (int i = 0; i < [banners count]; i++)
    
        Banner *banner = banners[i];

        if (banner != nil)
        
            [MagicalRecord saveWithBlock:^(NSManagedObjectContext *localContext)
             
                 Banner *localBanner = [banner MR_inContext:localContext];
                 [localBanner MR_deleteEntity];
              completion:^(BOOL success, NSError *error) 
             NSLog(@"I am here");
if(completionBlock)
completionBlock();
         ];
        
    

这样使用

[self.viewModel setBannerInactive:appLanguage withCompletion:^()

 if (self.viewModel.activeBanner != nil)
 
     [self.viewModel saveBanner:self.splashViewModel.activeBanner withCompletion:^()
         [self.viewModel deleteInactiveBanners withCompletion:nil];
      ];
 
else
     
     [self.viewModel deleteInactiveBanners withCompletion:nil];

];

【讨论】：

你的回答对我有帮助，所以我会支持你