Feedly Mark as Read not working on Objective-C

I'm trying to implement a method in my iOS app to mark an article as read using the Feedly API. However, I keep getting error responses:

{
    "errorCode": 400,
    "errorId": "sandbox-he.2015010906.2770040",
    "errorMessage": "no data"
}

This is the method:

- (void)markRead:(NSString*)articleID {
    NSLog(@"Artidle ID is: %@", articleID);

    NSUserDefaults *standardUserDefaults = [NSUserDefaults standardUserDefaults];
    NSString *accessToken = [standardUserDefaults objectForKey:@"AccessToken"];

    NSString *feedUrl = [NSURL URLWithString:@"https://sandbox.feedly.com/v3/markers"];

    NSError *error = nil;

    NSString *post =[[NSString alloc] initWithFormat:@"action=markAsRead&type=entries&entryIds=%@",articleID];
    NSLog(@"PostData: %@",post);

    NSData *postData = [post dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];

    NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
    [request setURL:feedUrl];
    [request setHTTPMethod:@"POST"];
    [request setValue:@"application/json" forHTTPHeaderField:@"Content-type"];
    [request setHTTPBody:postData];
    [request addValue:accessToken forHTTPHeaderField:@"Authorization"];

    //[NSURLRequest setAllowsAnyHTTPSCertificate:YES forHost:[url host]];

    NSError *errror = [[NSError alloc] init];
    NSHTTPURLResponse *response = nil;
    NSData *urlData=[NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&errror];

    NSLog(@"Response code: %ld", (long)[response statusCode]);

    if ([response statusCode] >= 200 && [response statusCode] < 300)
    {
        NSLog(@"Success marking this as read.");

    } else {
        if (error) NSLog(@"Error: %@", errror);
        NSLog(@"No success marking this as read.");
    }

}

The Feedly API describes that it requires this as input:

{
   "entryIds": [
       "TSxGHgRh4oAiHxRU9TgPrpYvYVBPjipkmUVSHGYCTY0=_14499073085:c034:d32dab1f",
       "TSxGHgRh4oAiHxRU9TgPrpYvYVBPjipkmUVSHGYCTY0=_1449255d60a:22c3491:9c6d71ab"
   ],
   "action": "markAsRead",
   "type": "entries"
}

In my opinion I'm providing this as input, so I actually expected a proper response. However, I keep getting 400 and can't seem to figure out what I'm doing wrong. I've been busting my head for hours on this.

Solution

Instead of using your current body data, try creating the data with following code:

NSDictionary *bodyDict = [NSDictionary dictionaryWithObjectsAndKeys:@[articleID],@"entryIds",
                          @"markAsRead",@"action",
                          @"entries",@"type", nil];

NSError *error;
NSData *postdata = [NSJSONSerialization dataWithJSONObject:bodyDict options:0 error:&error];
[request setHTTPBody:postData];

This will send the body as a JSON object.

Sending parameter like you did (with action=markAsRead&type=entries&entryIds=%@) is usually used when calling a web method with the GET request method. Take a look at POST vs GET for a better understanding.