Ios 当子类化RKObjectRequestOperation以检查错误时，如何重试失败的操作？

我已将RKManagedObjectRequestOperation子类化并重写以下方法

    - (void)setCompletionBlockWithSuccess:(void ( ^ ) ( RKObjectRequestOperation *operation , RKMappingResult *mappingResult ))success failure:(void ( ^ ) ( RKObjectRequestOperation *operation , NSError *error ))failure
{

    [super setCompletionBlockWithSuccess:^void(RKObjectRequestOperation *operation , RKMappingResult *mappingResult) {
        if (success) {
            success(operation, mappingResult);
        }

    }failure:^void(RKObjectRequestOperation *operation , NSError *error) {

        NSInteger statusCode = operation.HTTPRequestOperation.response.statusCode;
        switch (statusCode) {
            case  401: // not authenticated
            {
                MyError* errorResponse = (MyError*)[[error.userInfo objectForKey:@"RKObjectMapperErrorObjectsKey"] firstObject];
                if(errorResponse && [errorResponse.oauth2ErrorCode isEqualToString:@"invalid_token"]){

                    RKObjectRequestOperation* repeatOp = [operation copy];
                    [repeatOp setCompletionBlockWithSuccess:success failure:failure];
                    [[NSNotificationCenter defaultCenter] postNotificationName:@"InvalidTokenFailure" object:repeatOp];

                } else{

                    if (failure) {
                        failure(operation, error);
                    }

                }

            }
                break;

            default:
            {
                if (failure) {
                    failure(operation, error);
                }

            }
                break;
        }
    }];
}

然后，在失败通知的观察者中，我发出一个刷新oauth令牌的请求，如果成功，我想再次将原始请求排队，但是在从原始操作中替换querystring参数之后

在通知观察员的代码中：

-(void)restRequestFailedWithOperation:(NSNotification*)notification{

    RKManagedObjectRequestOperation *operation = (RKManagedObjectRequestOperation *)notification.object;
    if (operation) {

                // issue token refresh request and in its success block:
                ..... 

                 [[RKObjectManager sharedManager] enqueueObjectRequestOperation:operation];

         }      
}

---

我没有看到在RKManagedObjectRequestOperation中替换特定querystring参数的方法。而且，由于原始操作仍然具有旧令牌，因此再次将其排队将不起作用

一种解决方法是将oauth令牌附加到每个传出请求的问题转移到RKHTTPRequestOperation类的子类中，并重写该方法

-(NSURLRequest*)connection:(NSURLConnection *)connection willSendRequest:(NSURLRequest *)request redirectResponse:(NSURLResponse *)response{

}

这将确保每个传出请求将获得最新的oauth令牌。它使您无需使用新请求修改失败的操作

确保按如下方式注册子类（MyHTTPRequestOperation）：

[[RKObjectManager sharedManager] registerRequestOperationClass:[MyHTTPRequestOperation class]];

我不相信这是最好的办法。理想情况下，可以实现RKPaginator类设置的模式。RKPaginator允许在修改某些查询参数时轻松重复相同的请求