NSURLConnection works, but AFNetworking doesn't (on specific URL) - ios

Question

I set up a simple web server on an AWS EC2 instance and wrote a small test.php file that goes like this:
<?php
$dict = array("key" => "value", "test" => "Hello world");
echo json_encode($dict);
?>
In my browser I can go to http://'myInstanceIP'/test.php and I will get the encoded JSON response. I tried doing this in iOS and for some reason I can only get a successful response via NSURLConnection and not through AFNetworking. It's weird because the AFN code works if I input some other URL that will give me a JSON response, just not on my URL.
I call it in viewDidAppear just for testing:
- (void)viewDidAppear:(BOOL)animated
{
NSString *urlString = #"http://54.183.178.170/test.php";
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:urlString]];
AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc] initWithRequest:request];
operation.responseSerializer = [AFJSONResponseSerializer serializer];
[operation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
NSLog(#"%#", (NSDictionary *)responseObject);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog(#"Failed");
}];
[operation start];
}
I can't tell if it's the fault of my web server or AFN (since it works on NSURLConnection).
UPDATE:
Here's the failure code I'm getting from AFNetworking:
2014-09-02 11:50:11.538 testingAWS[26751:60b] Failed, error: Error Domain=com.alamofire.error.serialization.response Code=-1016 "Request failed: unacceptable content-type: text/html" UserInfo=0x8c4ce00 {com.alamofire.serialization.response.error.response=<NSHTTPURLResponse: 0x8d80fa0> { URL: http://54.183.178.170/test.php } { status code: 200, headers {
Connection = "Keep-Alive";
"Content-Length" = 34;
"Content-Type" = "text/html";
Date = "Tue, 02 Sep 2014 18:50:09 GMT";
"Keep-Alive" = "timeout=5, max=100";
Server = "Apache/2.4.7 (Ubuntu)";
"X-Powered-By" = "PHP/5.5.9-1ubuntu4.3";
} }, NSErrorFailingURLKey=http://54.183.178.170/test.php, NSLocalizedDescription=Request failed: unacceptable content-type: text/html, com.alamofire.serialization.response.error.data=<7b226b65 79223a22 76616522 2c227465 7374223a 2248656c 6c6f2077 6f726c64 227d>}

Answer 1

We can see here:
Code=-1016 "Request failed: unacceptable content-type: text/html"
That your problem should be happening because of this line:
operation.responseSerializer = [AFJSONResponseSerializer serializer];
For some reason your server must be returning a non-JSON response, and you are using a JSONResponseSerializer. So if you fix the server return type the correct format you'll probably be fine.
Or, you could just change the serializer type like this:
operation.responseSerializer = [AFHTTPResponseSerializer serializer];
if it's just for a testing purpose.

Answer 2

So it turns out I need to add the following line to my PHP, right before json_encode():
header('Content-type: application/json');
Then it works with AFNetworking as it should.