POST base 64 image string to a server on iOS - ios

Question

To my understanding, to use this website I have to convert an image to a base64 encoded image and then send it to this website. The website will then send me back a number (as a decimal).
https://docs.indico.io/docs/rest-api-image-analysis
I've tried using a number of steps, namely trying to alter a similar process used for sending text and receiving a number. Any tips?
UPDATE:
- (IBAction)press:(id)sender {
//UIImage *imager = photos.image;
NSData *imageData = UIImageJPEGRepresentation(photos.image, 1.0);
NSString *base64Img = [imageData base64EncodedStringWithOptions:NSDataBase64EncodingEndLineWithLineFeed];
//not sure if #"data" or #"data.json" and whether the base64img should be behind it
NSDictionary *parameters = #{#"data":base64Img};
NSMutableString *parameterString = [NSMutableString string];
for (NSString *key in [parameters allKeys]) {
if ([parameterString length]) {
[parameterString appendString:#"&"];
}
[parameterString appendFormat:#"%#=%#", key, parameters[key]];
NSURL *url = [NSURL URLWithString:#"http://apiv2.indico.io/contentfiltering?key='17767cb46eb4b4f568832be2c953022b"];
NSURLSession *session = [NSURLSession sharedSession];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
[request setHTTPMethod:#"POST"];
[request setHTTPBody:[parameterString dataUsingEncoding:NSUTF8StringEncoding]];
NSURLSessionDataTask *task = [session dataTaskWithRequest:request completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
if (!error) {
if ([data length]) {
NSDictionary *jsonResponse = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil];
//GET RESULT;
NSLog(#"A %#", parameters[#"results"]);
}
} else {
NSLog(#"%#", error);
}
}];
[task resume];
}
the results I get usually return as (null)

Answer 1

maybe try going
NSDictionary *parameters = #{#"data":base64Img};
NSError *error;
NSData *jsonData = [NSJSONSerialization dataWithJSONObject:parameters
options:nil
error:&error];
//do some error checking
NSURL *url = [NSURL URLWithString:#"http://apiv2.indico.io/contentfiltering?key='17767cb46eb4b4f568832be2c953022b"];
NSURLSession *session = [NSURLSession sharedSession];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
[request setHTTPMethod:#"POST"];
[request setHTTPBody:jsonData];
//...
just doing this off the top of my head so may need some tweaking

Answer 2

If I had to guess it looks like you've accidentally added a typo to your API key. In the line above:
http://apiv2.indico.io/contentfiltering?key='17767cb46eb4b4f568832be2c953022b
should instead read:
http://apiv2.indico.io/contentfiltering?key=17767cb46eb4b4f568832be2c953022b
Since URL parameters are sometimes quoted and I'm not extremely familiar with objective-c's internal request handling I would guess that that is leading to the strange behavior you're seeing.