Question

我正在编写一个Abstract类来从多个社交网络中获取数据。在考虑了我需要在这个类中使用的所有东西之后，在该类的其他子类中使用它我会开始编写一个简单的auth_token fetcher来获取facebook的授权以从页面获取所有状态更新轮廓。我没有看到什么是使代码工作的最佳方法：

+ (NSString *)requestAuthToken {
    NSString *authTokenKey = [[self socialNetworkName] stringByAppendingString:@"AuthToken"];
    NSString *authTokenDateKey = [[self socialNetworkName] stringByAppendingString:@"AuthTokenDate"];
    NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
    __block NSString *authToken = [userDefaults stringForKey:authTokenKey];
    NSDate *authTokenDate = (NSDate* )[userDefaults objectForKey:authTokenDateKey];
    NSTimeInterval expirationDate = [authTokenDate timeIntervalSinceNow];
    NSTimeInterval now = [[NSDate date] timeIntervalSinceNow];
    NSTimeInterval dateDiff = expirationDate - now;
    int diff = roundf(dateDiff / (60 * 60 * 24));

    if (authToken == nil|| diff >= kMaxDaysExpiratonForAuthToken) {
        DLog(@"AuthToken not Cached, requesting token with %@", [self socialNetworkName]);
        AFHTTPClient *httpClient = [[AFHTTPClient alloc] initWithBaseURL:[NSURL URLWithString:[self socialNetworkAPIURL]]];
        NSDictionary *parameters = [self socialNetworkAPIAuthTokenParameters];
        [httpClient getPath:[self socialNetworkAPIAuthTokenURLPath] parameters:parameters success:^(AFHTTPRequestOperation *operation, id responseObject) {
            authToken = [NSString stringWithUTF8String:[responseObject bytes]];
            [userDefaults setObject:[NSDate date] forKey:authTokenDateKey];
            [userDefaults setObject:authToken forKey:authTokenKey];
//            [userDefaults synchronize];
        } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
            DLog(@"error requesting the token %@", error);
        }];
    }

    return authToken;
}

我总是得到回报;

Answer 1

块以异步方式执行。因此，您应该在请求函数中传递类的对象。成功或失败时，block将使用该对象返回结果。

    + (NSString *)requestAuthToken:(id)objOfCallerClass {
....    
        if (authToken == nil|| diff >= kMaxDaysExpiratonForAuthToken) {
....
[objOfCallerClass accessToken: authToken];
            } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
                [objOfCallerClass accessToken: nil];
            }];
        }

        return authToken;
    }

等待块完成以返回令牌nsstring

1 个答案: