is there an example of AFHTTPClient posting json with AFNetworking?

Question

Looking for an example of how to post json with AFHTTPClient. I see that there is a postPath method which takes an NSDictionary and the AFJSONEncode method returns an NSData. Is there an easy way to serialize an object to NSDictionary, or is there an easier way using jsonkit?

I just need to post the object as json to a REST API.

UPDATE: So I tried passing a dictionary over but it seems to break on serializing a nested array.

For example, if I have an object:

Post* p = [[Post alloc] init];
p.uname = @"mike";
p.likes =[NSNumber numberWithInt:1];
p.geo = [[NSArray alloc] initWithObjects:[NSNumber numberWithFloat:37.78583], [NSNumber numberWithFloat:-122.406417], nil ];
p.place = @"New York City";
p.caption = @"A test caption";
p.date = [NSDate date];

who's get dictionary has data like the following:

{
    caption = "A test caption";
    date = "2011-12-13 17:58:37 +0000";
    geo =     (
        "37.78583",
        "-122.4064"
    );
    likes = 1;
    place = "New York City";

}

the serialization will either just fail outright or geo will not be serialized as an array but as a string literal like ("37.78583", "-122.4064");

Answer 1

If you're posting to a JSON REST API, there should be a particular mapping from object property to JSON key, right? That is, the server is expecting certain information in certain named fields.

So what you want to do is construct an NSDictionary or NSMutableDictionary with the keys used in the API and their corresponding values. Then, simply pass that dictionary into the parameters argument of any request method in AFHTTPClient. If the parameterEncoding property of the client is set to AFJSONParameterEncoding, then the body of the requests will automatically be encoded as JSON.

Answer 2

The best and simple way to do that is to subclass AFHTTPClient.

Use this code snippet

MBHTTPClient

#define YOUR_BASE_PATH @"http://sample.com"
#define YOUR_URL @"post.json"
#define ERROR_DOMAIN @"com.sample.url.error"

/**************************************************************************************************/
#pragma mark - Life and Birth

+ (id)sharedHTTPClient
{
    static dispatch_once_t pred = 0;
    __strong static id __httpClient = nil;
    dispatch_once(&pred, ^{
        __httpClient = [[self alloc] initWithBaseURL:[NSURL URLWithString:YOUR_BASE_PATH]];
        [__httpClient setParameterEncoding:AFJSONParameterEncoding];
        [__httpClient registerHTTPOperationClass:[AFJSONRequestOperation class]];
        //[__httpClient setAuthorizationHeaderWithUsername:@"" password:@""];
    });
    return __httpClient;
}

/**************************************************************************************************/
#pragma mark - Custom requests

- (void) post<#Objects#>:(NSArray*)objects
success:(void (^)(AFHTTPRequestOperation *request, NSArray *objects))success
failure:(void (^)(AFHTTPRequestOperation *request, NSError *error))failure
{
    [self postPath:YOUR_URL
       parameters:objects
          success:^(AFHTTPRequestOperation *request, id JSON){
              NSLog(@"getPath request: %@", request.request.URL);

              if(JSON && [JSON isKindOfClass:[NSArray class]])
              {
                  if(success) {
                      success(request,objects);
                  }
              }
              else {
                  NSError *error = [NSError errorWithDomain:ERROR_DOMAIN code:1 userInfo:nil];
                  if(failure) {
                      failure(request,error);
                  }
              }
          }
          failure:failure];
}

Then in your code just call

[[MBHTTPClient sharedHTTPClient]  post<#Objects#>:objects
                                          success:^(AFHTTPRequestOperation *request, NSArray *objects) {
    NSLog("OK");
}
                                          failure:(AFHTTPRequestOperation *request, NSError *error){
    NSLog("NOK %@",error);
}

objects is an NSArray (you can change it to NSDictonary) and will be encode in JSON format