Question

我将iCloud添加到现有应用中。同步工作正常但我需要排除某些实体，或者在我的某些核心数据被复制时提出解决方法。

例如：

CertificateColour被发送到表格视图，现在每行显示两次。

CertificateType在操作表中显示四个选项，现在有8行，每行都被复制一次。

我使用https://github.com/mluisbrown/iCloudCoreDataStack进行核心数据同步。

我查了Core data + iCloud: exclude certain attributes from sync?这提出了几件事：
1.创建一个单独的本地和云存储，听起来......很有希望但不确定这是我第一次尝试使用iCloud和Core数据。
2.第二个建议是同步到包含唯一设备标识符的实体，但这已被弃用，并且再次不确定具有核心数据的进程

AppDelegate.h

#import <UIKit/UIKit.h>
#import <sqlite3.h>
#import "PersistentStack.h"

@interface ICAppDelegate : UIResponder <UIApplicationDelegate>

@property (strong, nonatomic) UIWindow *window;
@property (strong, nonatomic) UINavigationController *navigationController;

@property (readonly, strong, nonatomic) NSManagedObjectContext *managedObjectContext;
@property (readonly, strong, nonatomic) NSManagedObjectModel *managedObjectModel;
@property (readonly, strong, nonatomic) NSPersistentStoreCoordinator *persistentStoreCoordinator;

- (void)saveContext;
- (NSURL *)applicationDocumentsDirectory;

@end

Appdelegate.m

@interface ICAppDelegate () <DBSessionDelegate, DBNetworkRequestDelegate>

//iCloud
@property (nonatomic, strong) PersistentStack* persistentStack;
@property (nonatomic, strong) NSManagedObjectContext* managedObjectContext;

@end

@implementation ICAppDelegate

@synthesize window = _window;
@synthesize navigationController = _navigationController;
@synthesize managedObjectContext = __managedObjectContext;
@synthesize managedObjectModel = __managedObjectModel;
@synthesize persistentStoreCoordinator = __persistentStoreCoordinator;



- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{

    //iCloud
    self.persistentStack = [[PersistentStack alloc] initWithStoreURL:self.storeURL modelURL:self.modelURL];
    self.managedObjectContext = self.persistentStack.managedObjectContext;



    BOOL populateData = NO;
    BOOL copyDb = YES;

    // Copy DB to documents directory
    if (copyDb == YES) {

        NSString *srcPath = [[NSBundle mainBundle] pathForResource:@"myApp" ofType:@"sqlite"];
        NSString *destPath = [[NSHomeDirectory() stringByAppendingPathComponent:@"Documents"] stringByAppendingPathComponent:@"myApp.sqlite"];

        if (![[NSFileManager defaultManager] fileExistsAtPath:srcPath]) {
            DebugLog(@"Source file doesn't exist");
        }
        if (![[NSFileManager defaultManager] fileExistsAtPath:destPath]) {
            DebugLog(@"Copying DB to documents directory");
            NSError *error = nil;
            [[NSFileManager defaultManager] copyItemAtPath:srcPath toPath:destPath error:&error];
            if (error != nil) {
                DebugLog(@"Copy failed %@", [error localizedDescription]);
            }
        }
    }


    /////*****ALL OF THIS IS DUPLICATED AND NEEDS EXCLUDING FROM ICLOUD BACK UP****////////////

        if (populateData) {

        DebugLog(@"Populating database");
        NSManagedObjectContext *context = [self managedObjectContext];

        Subscription *subscription = (Subscription *)[NSEntityDescription insertNewObjectForEntityForName:@"Subscription" inManagedObjectContext:context];
        subscription.subscribed = @NO;

        CertificateColour *red = (CertificateColour *)[NSEntityDescription insertNewObjectForEntityForName:@"CertificateColour" inManagedObjectContext:context];
        red.name = @"Red";
        red.redComponent = @1.0f;
        red.greenComponent = @0.0f;
        red.blueComponent = @0.0f;

        CertificateColour *purple = (CertificateColour *)[NSEntityDescription insertNewObjectForEntityForName:@"CertificateColour" inManagedObjectContext:context];
        purple.name = @"Purple";
        purple.redComponent = @0.4f;
        purple.greenComponent = @0.0f;
        purple.blueComponent = @0.6f;

        CertificateColour *green = (CertificateColour *)[NSEntityDescription insertNewObjectForEntityForName:@"CertificateColour" inManagedObjectContext:context];
        green.name = @"Green";
        green.redComponent = @0.0f;
        green.greenComponent = @0.6f;
        green.blueComponent = @0.2f;

        CertificateColour *blue = (CertificateColour *)[NSEntityDescription insertNewObjectForEntityForName:@"CertificateColour" inManagedObjectContext:context];
        blue.name = @"Blue";
        blue.redComponent = @0.0f;
        blue.greenComponent = @0.2f;
        blue.blueComponent = @1.0f;


        ICCertificateTypeManager *ctm = [ICCertificateTypeManager manager];

        CertificateType *type = [ctm newCertificateType];
        type.title = @"Works";
        type.identifier = @(Works);

        type = [ctm newCertificateType];
        type.title = @"Type1";
        type.identifier = @(Type1);

        type = [ctm newCertificateType];
        type.title = @"Type2";
        type.identifier = @(Type2);

        type = [ctm newCertificateType];
        type.title = @"Type4";
        type.identifier = @(Type3);

        [self saveContext];
    }

       if ([[ICWebServiceClient sharedInstance] isLoggedIn])
    {
        DebugLog(@"User is logged in ");
    }
    ////////////////////////////////////////////////////////////


    return YES;
}

- (BOOL)application:(UIApplication *)application handleOpenURL:(NSURL *)url {
    LogCmd();
    if ([[DBSession sharedSession] handleOpenURL:url]) {
        if ([[DBSession sharedSession] isLinked]) {
            DebugLog(@"handling url");
        }
        return YES;
    }

    return NO;
}

- (void)applicationWillResignActive:(UIApplication *)application
{

}

- (void)applicationDidEnterBackground:(UIApplication *)application
{

    [self.managedObjectContext save:NULL];
}

- (void)applicationWillEnterForeground:(UIApplication *)application
{

}

- (void)applicationDidBecomeActive:(UIApplication *)application
{

}

- (void)applicationWillTerminate:(UIApplication *)application
{

    [self saveContext];
}

- (void)saveContext
{
    NSError *error = nil;
    NSManagedObjectContext *managedObjectContext = self.managedObjectContext;
    if (managedObjectContext != nil) {
        if ([managedObjectContext hasChanges] && ![managedObjectContext save:&error]) {


            NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
            abort();
        } 
    }
}


#pragma mark - DBSessionDelegate

- (void)sessionDidReceiveAuthorizationFailure:(DBSession*)session userId:(NSString *)userId
{
    LogCmd();
}

#pragma mark - DBNetworkRequestDelegate

static int outstandingRequests;

- (void)networkRequestStarted {
    outstandingRequests++;
    if (outstandingRequests == 1) {
        [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:YES];
    }
}

- (void)networkRequestStopped {
    outstandingRequests--;
    if (outstandingRequests == 0) {
        [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:NO];
    }
}


#pragma mark - Core Data stack

// Returns the managed object context for the application.
// If the context doesn't already exist, it is created and bound to the persistent store coordinator for the application.
- (NSManagedObjectContext *)managedObjectContext
{
    if (__managedObjectContext != nil) {
        return __managedObjectContext;
    }

    NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
    if (coordinator != nil) {
        __managedObjectContext = [[NSManagedObjectContext alloc] init];
        [__managedObjectContext setPersistentStoreCoordinator:coordinator];
    }
    return __managedObjectContext;
}

// Returns the managed object model for the application.
// If the model doesn't already exist, it is created from the application's model.
- (NSManagedObjectModel *)managedObjectModel
{
    if (__managedObjectModel != nil) {
        return __managedObjectModel;
    }
    NSURL *modelURL = [[NSBundle mainBundle] URLForResource:@"myApp" withExtension:@"momd"];
    __managedObjectModel = [[NSManagedObjectModel alloc] initWithContentsOfURL:modelURL];
    return __managedObjectModel;
}

// Returns the persistent store coordinator for the application.
// If the coordinator doesn't already exist, it is created and the application's store added to it.
- (NSPersistentStoreCoordinator *)persistentStoreCoordinator
{
    if (__persistentStoreCoordinator != nil) {
        return __persistentStoreCoordinator;
    }

    NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"myApp.sqlite"];

    NSError *error = nil;
    __persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];
    if (![__persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeURL options:nil error:&error]) {





        NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
        abort();
    }    

    return __persistentStoreCoordinator;
}

#pragma mark - Application's Documents directory

// Returns the URL to the application's Documents directory.
- (NSURL *)applicationDocumentsDirectory
{
    return [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] lastObject];
}


#pragma mark - iCloud store

- (NSURL*)storeURL
{
    NSURL* documentsDirectory = [[NSFileManager defaultManager] URLForDirectory:NSDocumentDirectory inDomain:NSUserDomainMask appropriateForURL:nil create:YES error:NULL];
    return [documentsDirectory URLByAppendingPathComponent:@"myApp.sqlite"];
}

- (NSURL*)modelURL
{
    return [[NSBundle mainBundle] URLForResource:@"myApp" withExtension:@"momd"];
}


@end

Answer 1

使用多个持久存储实际上是从iCloud中排除特定实体类型的唯一选择。您可以通过在同一个持久性存储协调器上多次调用addPersistentStoreWithType但使用不同的持久性存储文件（它可以称为协调器，因为它可以在多个持久性存储之间进行协调）来实现。对其中一个商店使用iCloud选项，但对另一个商店不使用。

您可以使用具有不同实体的两个单独的托管对象模型，也可以使用具有不同配置选项的单个模型。要么是有效的。

您可能遇到的问题是您无法在不同持久性商店文件中的实例之间创建关系。（从技术上讲，你可以创建它们，你只能保存它们，这在大多数情况下会使它们变得无用）。您的CertificateType实体听起来与其他实例有关系，但这不适用于多个商店。

您可以做的是同步每个对象，但添加代码以检测重复项并处理它们。在Apple＆＃34; SharedCoreData＆＃34;中有一个很好的例子。示例应用程序来自＆＃34;使用iCloud和核心数据＆＃34; 2012年WWDC会议，但我现在无法在网上找到该副本。你可以做类似

的事情

等待NSPersistentStoreDidImportUbiquitousContentChangesNotification
当它到达时，请查看通知userInfo以查看是否包含了任何CertificateType个对象。
如果是，请对该实体进行抓取以查找并匹配重复项
以对您的应用程序有意义的方式清理这些重复项。

更新：我忘记了我做过blog post which covers this in more detail。我还找到了WWDC 2012 sample code bundle（链接需要当前开发者帐户）的链接，其中包含SharedCoreData。该演示中的许多内容已过时，但重复的删除代码与以往一样有效。

将核心数据与iCloud同步 - 不包括实体

1 个答案: