来自服务器的Restkit json错误响应消息

Question

我已经花了很多时间来解决这个问题.我使用Restkit 0.9.3与Object Mapping 2.0.所有数据都是JSON.我可以正确地进行GET,POST,PUT和DELETE操作,它是我没有捕获的响应体并且正确地映射..

所以我的问题是,当出现问题时,我的restful api会返回错误.我想用restkit映射这些错误,fx返回此错误:

{"code":"401","message":"未经授权"}

如何映射这个json正确？我尝试了很多东西,可以使用一些指导 - 或者请举一个例子.

Answer 1

对于RestKit v0.20

假设您的HTTP正文是:

{"error": "..."}

你创建了一个映射和描述符:

RKObjectMapping *errorMapping = [RKObjectMapping mappingForClass:[RKErrorMessage class]];

[errorMapping addPropertyMapping: [RKAttributeMapping attributeMappingFromKeyPath:@"error" toKeyPath:@"errorMessage"]];
RKResponseDescriptor *errorResponseDescriptor = [RKResponseDescriptor responseDescriptorWithMapping:errorMapping pathPattern:nil keyPath:nil statusCodes:RKStatusCodeIndexSetForClass(RKStatusCodeClassClientError)];
[objectManager addResponseDescriptor:errorResponseDescriptor];

然后你可以从你的失败块访问它:

failure:^(RKObjectRequestOperation *operation, NSError *error) {
                NSLog(@"errorMessage: %@", [[error userInfo] objectForKey:RKObjectMapperErrorObjectsKey]);
            }

这使用内置RKErrorMessage类,但您可以使用其他字段创建自己的自定义类.

Answer 2

对于版本0.10.0,此响应错误可以映射如下:

RKObjectMapping *errorMapping = [RKObjectMapping mappingForClass:[RKErrorMessage class]];
[errorMapping mapKeyPath:@"message" toAttribute:@"errorMessage"];
[[[RKObjectManager sharedManager] mappingProvider] setErrorMapping:errorMapping];

返回错误的请求将调用以下委托方法:

- (void)objectLoader:(RKObjectLoader *)objectLoader didFailWithError:(NSError *)error {
    NSArray *errorMessages = [[error userInfo] objectForKey:RKObjectMapperErrorObjectsKey];
    RKErrorMessage *errorMessage = [errorMessages objectAtIndex:0]; // First and only object in your case.
    NSString *message = [errorMessage errorMessage];
    NSInteger code = [[objectLoader response] statusCode];
    NSLog(@"ERROR: [%d] %@", code, message); // => ERROR: [401] Unauthorized
}

Answer 3

使用Restkit v0.2x,您可以以RKErrorMessage.userInfo[ Swift ]方式将所需的所有JSON属性映射到现有的Dictionary属性:

let errorMapping = RKObjectMapping(forClass: RKErrorMessage.self);
errorMapping.addPropertyMapping(RKAttributeMapping(fromKeyPath: nil, toKeyPath: "userInfo"));

let errorResponseDescriptor = RKResponseDescriptor(
    mapping: errorMapping,
    method: RKRequestMethod.Any,
    pathPattern: nil,
    keyPath: "error", //or nil, according to your json response
    statusCodes: RKStatusCodeIndexSetForClass(UInt(RKStatusCodeClassClientError)))
);

因此,您可以像这样映射错误JSON响应:

{
    "error": {
        "message": "Error message",
        "cause": "...",
        "code": "my_error_code",
        "url": "..."
        ...
    }
}

并RKErrorMessage在failure闭包中检索所有属性,如下所示:

failure: { (operation, error) -> Void in
    if let errorMessage = error.userInfo?[RKObjectMapperErrorObjectsKey]?.firstObject as? RKErrorMessage{
        let message = errorMessage.userInfo["message"] as! String;
        let code = errorMessage.userInfo["code"] as! String;
        ...
    }
}

我希望这对某人有帮助!