从 iCloud 备份中排除：NSURLIsExcludedFromBackupKey

Question

我的应用第二次被拒绝，我损失了 3 周 :(

第一次提交时，我只排除了在 iCloud 中备份的目录。苹果拒绝了...

第二次提交时，我将下载的 DIRECTORIES & PICTURES 排除在 iCloud 中备份。 Apple 再次拒绝... Apple 还抱怨我的应用内购买没有“恢复”功能，而事实上，我确实有一个“恢复”按钮，并且在我测试时它有效。

我已经按照 Apple 的建议通过使用 NSURLIsExcludedFromBackupKey 将文件排除在备份之外来完成。 Macmade's 在stackoverflow here 上发表了一条有趣的评论：

有时，Apple 审核人员认为您的数据可以重新生成，当 它不是。然后你必须解释为什么必须备份数据

审稿人多久误解一次，我们必须向他们解释内容需要离线且不可重新生成？

这是我用来从 iCloud 中排除我的文件和目录的代码。有没有发现什么问题？

- (BOOL)addSkipBackupAttributeToItemAtURL:(NSURL *)URL
{
    // There's a chance the download failed, but don't assert here
    //assert([[NSFileManager defaultManager] fileExistsAtPath: [URL path]]);

    NSError *error = nil;
    BOOL success = [URL setResourceValue:[NSNumber numberWithBool:YES]
                                  forKey:NSURLIsExcludedFromBackupKey
                                   error: &error];
    if(!success){
        NSLog(@"Error excluding %@ from backup %@", [URL lastPathComponent], error);
    }
    return success;
}

//Download picture from Google and exclude it from being backed-up in iCloud
- (void)downloadFetcher:(GTMHTTPFetcher *)fetcher
       finishedWithData:(NSData *)data
                  error:(NSError *)error
{

    if (error == nil) {

        // successfully retrieved this photo's data; save it to disk
        GDataEntryPhoto *photoEntry = [fetcher propertyForKey:@"photo entry"];

        // Create album directory if it doesn't already exist
        NSString *path = [self findOrCreateApplicationSupportSubPath:[photoEntry albumTitle]];
        path = [path stringByAppendingPathComponent:[[photoEntry title] stringValue]];

        if (path != nil) {

            // Write to disk
            BOOL didSave = [data writeToFile:path
                                     options:NSDataWritingAtomic
                                       error:&error];
            if (didSave) {

                // Exclude file from being backed up in iCloud
                NSURL *url = [NSURL fileURLWithPath:path];
                BOOL excludeBackupResult = [self addSkipBackupAttributeToItemAtURL:url];

                if (excludeBackupResult == NO) {
                    NSLog(@"Error excluding FILE from iCloud: %@", path);
                }

                // Update the download progress bar
                _downloadedFileCounter = _downloadedFileCounter + 1;
                float progress = _downloadedFileCounter / kMaleWireframeImagesTotal;
                [self updateProgress:progress];

                // The download completed. -2 just incase a package is lost, but let the user move on...
                if (_downloadedFileCounter >= _downloadableFilesTotal -2) {
                    [_panel6 downloadCompleted];
                }

            } else {
                // error saving file.  Perhaps out of space?  Write permissions error?
                NSLog(@"Save anatomy picture failed: %@", error.localizedDescription);
            }

        } else {
            NSLog(@"downloadFetcher: Cannot create directory");
        }
    } else {
        NSLog(@"downloadFetcher failed: %@", error);
    }
}

//Create directory and exclude it from being backed-up in iCloud
-(NSString*)findOrCreateApplicationSupportSubPath:(NSString*)subPath
{

    NSString *resolvedPath;
    NSArray *appSupportDir = NSSearchPathForDirectoriesInDomains(NSApplicationSupportDirectory, NSUserDomainMask, YES);

    if ([appSupportDir count] != 0) {

        resolvedPath = [appSupportDir objectAtIndex:0];

        // Append the name of this application
        NSString *executableName = [[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleExecutable"];
        resolvedPath = [resolvedPath stringByAppendingPathComponent:executableName];
        resolvedPath = [resolvedPath stringByAppendingPathComponent:subPath];

        NSFileManager *manager = [NSFileManager defaultManager];
        if (![manager fileExistsAtPath:resolvedPath]) {

            // Path doesn't exist, creates it
            NSError *error;
            BOOL successful = [manager createDirectoryAtPath:resolvedPath withIntermediateDirectories:YES attributes:nil error:&error];

            if(!successful) {
                NSLog(@"ERROR creating APP Support Sub-Directory: %@", error.localizedDescription);
                return nil;
            } else {

                // Exclude path from backing-up in iCloud
                NSURL *url = [NSURL fileURLWithPath:resolvedPath];
                BOOL excludeBackupResult = [self addSkipBackupAttributeToItemAtURL:url];

                if(!excludeBackupResult){
                    NSLog(@"Error excluding DIRECTORY from iCloud backup. This is a violation to their guideline.");
                    return  nil;
                }
            }
        }

    } else {
        NSLog(@"No Application Support Path available");
        return  nil;
    }

    return resolvedPath;
}

Answer 1

我认为诀窍是添加 NSURLIsExcludedFromBackupKey 或确保该目录位于文档目录之外。我通过将文档移动到 Library/Application Support 文件夹来做到这一点（因为它在 /tmp 或 /Caches 文件夹中没有意义）：

- (void)createNewRefFolder
{
    NSError *error;

    // store in /Library/Application Support/BUNDLE_IDENTIFIER/Reference
    // make sure Application Support folder exists
    NSURL *applicationSupportDirectory = [[NSFileManager defaultManager] URLForDirectory:NSApplicationSupportDirectory
                                                                                inDomain:NSUserDomainMask
                                                                       appropriateForURL:nil
                                                                                  create:YES
                                                                                   error:&error];

    if (error) {
        NSLog(@"KCDM: Could not create application support directory. %@", error);
    }

    NSURL *referenceFolder = [applicationSupportDirectory URLByAppendingPathComponent:@"Reference" isDirectory:YES];
    if (![[NSFileManager defaultManager] createDirectoryAtPath:[referenceFolder path]
                                   withIntermediateDirectories:YES
                                                    attributes:nil
                                                         error:&error]) {
        NSLog(@"KCDM: Error creating Reference folder: %@ ...", error);
    }

    BOOL success = [referenceFolder setResourceValue:@YES forKey: NSURLIsExcludedFromBackupKey error: &error];
    if(!success){
        NSLog(@"KCDM: Error excluding %@ from backup %@", referenceFolder, error);
    }
}

Answer 2

从以前的答案中更新一点。

您必须检查文件是否存在。否则会报这个错误，

Error excluding [FileName] from backup: 
Error Domain=NSCocoaErrorDomain Code=4 "The file “[FileName]” doesn’t exist." 
 ... 

我不确定我们是否应该检查该值是否已更新。 例如API是否重置已经设置的值。如果它尝试再次更新文件系统以获得更耗时的设定值，我猜。

更新方法...

+ (BOOL)addSkipBackupAttributeToURLAtPath:(NSURL *)url
{
    if (!url) return NO;
    if (![[NSFileManager defaultManager] fileExistsAtPath:url.path]) return NO;

    NSError *error = nil;
    NSNumber *value = nil;
    BOOL success = [url getResourceValue:&value forKey:NSURLIsExcludedFromBackupKey error:&error];
    if (value.boolValue == YES) return YES;

    success = [url setResourceValue:[NSNumber numberWithBool:YES]
                                  forKey:NSURLIsExcludedFromBackupKey error:&error];
    if(!success){
        NSLog(@"Error excluding %@ from backup: %@", [url lastPathComponent], error);
    }
    return success;
}

+ (BOOL)addSkipBackupAttributeToFileAtPath:(NSString *)path
{
    if (!path) return NO;
    return [self addSkipBackupAttributeToURLAtPath:[NSURL fileURLWithPath:path]];
}