在没有互联网连接的情况下加载数据时出错（Restkit）

Question

通过 RKObjectManager 进行其余调用后，当我没有互联网连接时，它不会加载对象。我用domain.local 进行测试，但我的WIFI 已关闭。

我知道我可以用“reachabilityObserver”来实现，但我不知道如何做到这一点。

我的代码：

#import "ViewInformationForm.h"
#import <RestKit/RestKit.h>

@interface User : NSObject {
    NSNumber*        _user_forfait;
    NSNumber*        _user_client_free;
    NSNumber*        _user_demande_portabilite;
    NSNumber*        _user_mail_confirm;
    NSNumber*        _user_mail_enregistrement_inscrption;
    NSNumber*        _user_mail_depart_expedition;
    NSNumber*        _user_mail_arrivee_expedition;
    NSNumber*        _user_activation;
    NSNumber*        _user_portabilite;
}

@property (nonatomic, retain) NSNumber*        user_forfait;
@property (nonatomic, retain) NSNumber*        user_client_free;
@property (nonatomic, retain) NSNumber*        user_demande_portabilite;
@property (nonatomic, retain) NSNumber*        user_mail_confirm;
@property (nonatomic, retain) NSNumber*        user_mail_enregistrement_inscrption;
@property (nonatomic, retain) NSNumber*        user_mail_depart_expedition;
@property (nonatomic, retain) NSNumber*        user_mail_arrivee_expedition;
@property (nonatomic, retain) NSNumber*        user_activation;
@property (nonatomic, retain) NSNumber*        user_portabilite;

@end

@implementation User

@synthesize user_forfait = _user_forfait;
@synthesize user_client_free = _user_client_free;
@synthesize user_demande_portabilite = _user_demande_portabilite;
@synthesize user_mail_confirm = _user_mail_confirm;
@synthesize user_mail_enregistrement_inscrption = _user_mail_enregistrement_inscrption;
@synthesize user_mail_depart_expedition = _user_mail_depart_expedition;
@synthesize user_mail_arrivee_expedition = _user_mail_arrivee_expedition;
@synthesize user_activation = _user_activation;
@synthesize user_portabilite = _user_portabilite;

@end


@implementation ViewInformationForm;
@synthesize picker,pickerDate, forfaitNames;
@synthesize forfaitText, TextDateEnregistrement;


- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}
- (void)LoadData {


    RKObjectMapping* mapping = [RKObjectMapping mappingForClass:[User class]];
    [mapping mapKeyPathsToAttributes:
     @"data.user_forfait", @"user_forfait",
     @"data.user_client_free", @"user_client_free",
     @"data.user_demande_portabilite", @"user_demande_portabilite",
     @"data.user_mail_confirm", @"user_mail_confirm",
     @"data.user_mail_enregistrement_inscrption", @"user_mail_enregistrement_inscrption",
     @"data.user_mail_depart_expedition", @"user_mail_depart_expedition",
     @"data.user_mail_arrivee_expedition", @"user_mail_arrivee_expedition",
     @"data.user_activation", @"user_activation",
     @"data.user_portabilite", @"user_portabilite",
     nil];

    RKObjectManager *objectManager = [RKObjectManager sharedManager];


    NSString* urlUID = [NSString stringWithFormat:@"/user/data?uid=%@",uuid];
    RKObjectLoader *objectLoader = [objectManager objectLoaderWithResourcePath:urlUID delegate:self];
    objectLoader.method = RKRequestMethodGET;
    objectLoader.objectMapping = mapping;
    [objectLoader send];

}


- (void)objectLoader:(RKObjectLoader*)objectLoader didLoadObjects:(NSArray*)objects {
    User* user = [objects objectAtIndex:0];

    NSString* info = [NSString stringWithFormat:
                      @"\n user_forfait : %@ \n"
                      @"user_client_free : %@",[user user_forfait], [user user_client_free]];
    NSLog(@"%@",info);
}

- (void)objectLoader:(RKObjectLoader *)objectLoader didFailWithError:(NSError *)error {
    RKLogError(@"Load of RKRequest %@ failed with error: %@", objectLoader, error);                      
}

- (void)didReceiveMemoryWarning
{
    // Releases the view if it doesn't have a superview.
    [super didReceiveMemoryWarning];

    // Release any cached data, images, etc that aren't in use.
}

#pragma mark - View lifecycle

/*
// Implement loadView to create a view hierarchy programmatically, without using a nib.
- (void)loadView
{
}
*/


// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad
{
    [RKObjectManager objectManagerWithBaseURL:gRKCatalogBaseURL];



    [self LoadData];
    [super viewDidLoad];
    self.forfaitNames = [[NSArray alloc] initWithObjects:
                         @"-- Sélectionnez un forfait --", @"Forfait 19,99 €", @"Forfait 15,90 €", @"Forfait 2 €",
                         @"Forfait 0 €", nil];
}

错误：

2012-01-24 09:59:32.120 Free M. Stats[13438:10703] I restkit:RKLog.m:30 RestKit initialized...
2012-01-24 09:59:32.127 Free M. Stats[13438:10703] I restkit.network.reachability:RKReachabilityObserver.m:369 Network availability has been determined for reachability observer <RKReachabilityObserver: 0x8987300 host=0.0.0.0 isReachabilityDetermined=YES isMonitoringLocalWiFi=652464 reachabilityFlags=-R tc----->
2012-01-24 09:59:32.129 Free M. Stats[13438:10703] E restkit.network:RKRequest.m:464 Failed to send request to http://freemobile-stats.local/user/data?uid=b070b4f0a581cf1a16312b7bbb31353c due to unreachable network. Reachability observer = <RKReachabilityObserver: 0x8987300 host=0.0.0.0 isReachabilityDetermined=YES isMonitoringLocalWiFi=652464 reachabilityFlags=-R tc----->
2012-01-24 09:59:32.130 Free M. Stats[13438:10703] E app:ViewInformationForm.m:102 Load of RKRequest <RKObjectLoader: 0x6e69050> failed with error: Error Domain=org.restkit.RestKit.ErrorDomain Code=2 "The client is unable to contact the resource at http://freemobile-stats.local/user/data?uid=b070b4f0a581cf1a16312b7bbb31353c" UserInfo=0x6c99270 {NSLocalizedDescription=The client is unable to contact the resource at http://freemobile-stats.local/user/data?uid=b070b4f0a581cf1a16312b7bbb31353c}

谢谢您的帮助。 AO。

Answer 1

这是在 RestKit 中注册可达性通知的方式：

// Register for changes in network availability
NSNotificationCenter* center = [NSNotificationCenter defaultCenter];
[center addObserver:self selector:@selector(reachabilityDidChange:) name:RKReachabilityDidChangeNotification object:nil];

在这里您可以捕获通知：

- (void)reachabilityDidChange:(NSNotification *)notification {
    RKReachabilityObserver* observer = (RKReachabilityObserver *) [notification object];
    RKReachabilityNetworkStatus status = [observer networkStatus];
    if (RKReachabilityNotReachable == status) {
        RKLogInfo(@"No network access!");
    } else if (RKReachabilityReachableViaWiFi == status) {
        RKLogInfo(@"Online via WiFi!");
    } else if (RKReachabilityReachableViaWWAN == status) {
        RKLogInfo(@"Online via Edge or 3G!");
    }
}

Answer 2

您甚至不必注册 Restkit 可访问性通知系统，因为它已经在 RKRequest 方法中实现了。

因此，如果没有检测到互联网连接，您的请求将失败，并且该委托（您可能已经实现）将被调用：

- (void)objectLoader:(RKObjectLoader *)objectLoader didFailWithError:(NSError *)error {
    // No internet !
}

请注意，该委托也可能因其他原因而被调用，例如当您的映射中存在错误时数据。但对于简单的情况，对于你想做的事情来说应该没问题！

Answer 3

显然，如果没有 Iternet 连接，它不会从 Internet 加载数据。您可能想尝试预先实现的 Reachability 类之一，例如： http://developer.apple.com/library/ios/#samplecode/Reachability/Listings/Classes_Reachability_h.html#//apple_ref/doc/uid/DTS40007324-Classes_Reachability_h-DontLinkElementID_5