RestKit 0.20 无法从服务器获取数据

Posted 2023-03-05

【中文标题】RestKit 0.20 无法从服务器获取数据

【英文标题】：RestKit 0.20 can't get data from server

【发布时间】：2014-11-02 12:35:36

【问题描述】：

我是 Core Data 和 RestKit 的新手，我已经阅读了很多关于 Core Data 和 RestKit 的教程，但我仍然无法从服务器获取数据。在我的应用程序中，我需要获取数据，将其存储在设计中并从数据库加载（如果有或没有互联网连接），我知道 RestKit 可以为我做到这一点，但是当我尝试从 http://salatiki.com.ua/api/get.php?getSaladsType 获取数据时我看到一些错误，但没有任何反应，请帮助我，我做错了什么？我将非常感谢任何有用的参考资料。谢谢。

我有带有“SCategory”实体的 Model.xxdatamodelid

#import <Foundation/Foundation.h>
#import <CoreData/CoreData.h>

@interface SCategory : NSManagedObject

@property (nonatomic, retain) NSString * cName;
@property (nonatomic, retain) NSNumber * cId;
@property (nonatomic, retain) NSString * cSection;
@property (nonatomic, retain) NSString * cImage;

@end

在 AppDelegate.m 中

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

    NSManagedObjectModel *managedObjectModel = [NSManagedObjectModel mergedModelFromBundles:nil];
    RKManagedObjectStore *managedObjectStore = [[RKManagedObjectStore alloc] initWithManagedObjectModel:managedObjectModel];
    [RKMIMETypeSerialization registerClass:[RKNSJSONSerialization class] forMIMEType:@"text/html"];
    NSError *error = nil;
    BOOL success = RKEnsureDirectoryExistsAtPath(RKApplicationDataDirectory(), &error);
    if (! success) 
        RKLogError(@"Failed to create Application Data Directory at path '%@': %@", RKApplicationDataDirectory(), error);
    
    NSString *path = [RKApplicationDataDirectory() stringByAppendingPathComponent:@"Store.sqlite"];
    NSPersistentStore *persistentStore = [managedObjectStore addSQLitePersistentStoreAtPath:path fromSeedDatabaseAtPath:nil withConfiguration:nil options:nil error:&error];
    if (! persistentStore) 
        RKLogError(@"Failed adding persistent store at path '%@': %@", path, error);
    
    [managedObjectStore createManagedObjectContexts];

    RKObjectManager *manager = [RKObjectManager managerWithBaseURL:[NSURL URLWithString:@"http://salatiki.com.ua"]];
    manager.managedObjectStore = managedObjectStore;

    RKEntityMapping *categoryMapping = [RKEntityMapping mappingForEntityForName:NSStringFromClass([SCategory class]) inManagedObjectStore:managedObjectStore];
    [categoryMapping addAttributeMappingsFromDictionary:@ @"img": @"cImage",
                                                           @"section": @"cSection",
                                                           @"vid" : @"cId",
                                                           @"vname" : @"cName" ];

    NSIndexSet *statusCodes = RKStatusCodeIndexSetForClass(RKStatusCodeClassSuccessful); // Anything in 2xx
    RKResponseDescriptor *responseDescriptor = [RKResponseDescriptor responseDescriptorWithMapping:categoryMapping method:RKRequestMethodGET pathPattern:@"/api/get.php?getSaladsType" keyPath:nil statusCodes:statusCodes];

    [[RKObjectManager sharedManager] addResponseDescriptor:responseDescriptor];
    [manager getObjectsAtPath:@"/api/get.php?getSaladsType" parameters:nil success:^(RKObjectRequestOperation *operation, RKMappingResult *mappingResult) 
        NSLog(@"map arr: %@", mappingResult.array);
     failure:^(RKObjectRequestOperation *operation, NSError *error) 
        NSLog(@"request error");
    ];

    // Override point for customization after application launch.
    return YES;

日志：

    014-11-02 13:31:41.742 Salatiki[2000:3713] E restkit.network:RKObjectRequestOperation.m:213 GET 'http://salatiki.com.ua/api/get.php?getSaladsType' 
(200 OK / 0 objects) [request=0.0000s mapping=0.0000s total=0.0267s]: Error
 Domain=org.restkit.RestKit.ErrorDomain Code=1001 "No response descriptors match the 
response loaded." UserInfo=0x7f9fb883c880 NSLocalizedFailureReason=A 200 response was 
loaded from the URL 'http://salatiki.com.ua/api/get.php?getSaladsType', which failed to 
match all (0) response descriptors:, NSErrorFailingURLStringKey=http://salatiki.com.ua/api/get.php?getSaladsType, 
NSErrorFailingURLKey=http://salatiki.com.ua/api/get.php?getSaladsType, 
NSUnderlyingError=0x7f9fb883c3c0 "No mappable object representations were found at the 
key paths searched.", keyPath=null, NSLocalizedDescription=No response descriptors match 
the response loaded.
    2014-11-02 13:31:41.766 Salatiki[2000:613] I restkit.network:RKObjectRequestOperation.m:150 GET 'http://salatiki.com.ua/api/get.php?
getSaladsType'
    2014-11-02 13:31:41.766 Salatiki[2000:613] request error

【参考方案1】：

您将难以处理http://salatiki.com.ua/api/get.php?getSaladsType 的 URL，因为您在查询参数中赋予了很多意义，而 RestKit 不将查询参数用于响应描述符模式。

如果您只对这一请求使用get.php，那么您可以从响应描述符路径模式中删除?getSaladsType，它应该可以工作。如果您将它用于多种用途，那么您需要停止使用 RestKit，更改服务器以便不使用类似的查询参数或编辑 RestKit...

【参考方案2】：

最后我找到了解决方案，所有问题都在RKResponseDescriptor，pathPattern 在我的情况下应该为零，我不知道为什么，但它有效！