Parsing JSON with NSJSONSerialization: Error 3840 - Data Corrupted? - json

Question

I've read many Q/As on this problem but couldn't find an answer that fits my situation.
I retrieve a JSON response from a REST service I've created in PHP. This is my code:
NSURLResponse *response = nil;
NSError *theError1 = nil;
NSError *theError2 = nil;
NSURL *webServiceUrl = [NSURL URLWithString:#"http://..."];
NSURLRequest *request = [NSURLRequest requestWithURL:webServiceUrl cachePolicy:NSURLRequestReturnCacheDataElseLoad timeoutInterval:30];
NSData *theData = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&theError1];
NSString *dataString = [[NSString alloc] initWithData:theData encoding:NSUTF8StringEncoding];
NSLog(#"%#", dataString);
id json = [NSJSONSerialization JSONObjectWithData:theData options:NSJSONReadingAllowFragments | NSJSONReadingMutableContainers error:&theError2];
if (theError2 != nil)
NSLog(#"%#", theError2);
When I invoke the REST call in the browser, I see the following response, which seems identical to what XCode logs:
{
"Name": "REST Service",
"Product": "REST Test",
"Version": "1.0.0.0",
"Copyright": "2013 Test Company"
}
When I execute above code, however, the following error is created and logged:
Error Domain=NSCocoaErrorDomain Code=3840 "The data couldn’t be read because it has been corrupted." (Invalid value around character 3.) UserInfo=0x100547430 {NSDebugDescription=Invalid value around character 3.}
What am I doing wrong?

Answer 1

OK, as always, checking the actual data instead of the string representation pays - thanks #Bavarious.
It turns out that the PHP script(s) in charge of creating the JSON were all "UTF8 with BOM", so PHP returned a BOM for every script involved.
Once I changed all the PHP files to "UTF8 without BOM" everything seems to be fine - need to test this on the MAC though.
Sorry to interrupt, keep up the good work.
(#Bavarious: If you'd like to write an answer, I'd be happy to upvote and accept it, as you pointed me to the solution).
Was able to parse the JSON now as expected. Making a mental note to always double-check the text file encoding.

Answer 2

NSURL *theURL = [NSURL URLWithString:#"http://yourdataurl"];
NSMutableURLRequest *storeRequest = [NSMutableURLRequest requestWithURL:theURL cachePolicy:NSURLRequestReloadIgnoringCacheData timeoutInterval:10];
NSOperationQueue *queue = [[NSOperationQueue alloc] init];
[NSURLConnection sendAsynchronousRequest:storeRequest queue:queue
completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {
if (!connectionError) {
NSError *error;
NSString *dataStr = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSData *theData = [dataStr dataUsingEncoding:NSUTF8StringEncoding];
NSDictionary *jsonResponse = [NSJSONSerialization JSONObjectWithData:theData options:0 error:&error];
if (!jsonResponse || error)
{
NSLog(#"Error");
}
else
{
// Everything is ok..
}
}
}];