Question

I am interested in detecting the MIME-type for a file in the documents directory of my iPhone application. A search through the docs did not provide any answers.

Answer 1

It’s a bit hacky, but it should work, don’t know for sure because I’m just guessing at it

There are two options:

1. If you just need the MIME type, use the timeoutInterval: NSURLRequest.
2. If you want the data as well, you should use the commented out NSURLRequest.

Make sure to perform the request in a thread though, since it’s synchronous.

NSString* filePath = [[NSBundle mainBundle] pathForResource:@"imagename" ofType:@"jpg"];
NSString* fullPath = [filePath stringByExpandingTildeInPath];
NSURL* fileUrl = [NSURL fileURLWithPath:fullPath];
//NSURLRequest* fileUrlRequest = [[NSURLRequest alloc] initWithURL:fileUrl];
NSURLRequest* fileUrlRequest = [[NSURLRequest alloc] initWithURL:fileUrl cachePolicy:NSURLCacheStorageNotAllowed timeoutInterval:.1];

NSError* error = nil;
NSURLResponse* response = nil;
NSData* fileData = [NSURLConnection sendSynchronousRequest:fileUrlRequest returningResponse:&response error:&error];

fileData; // Ignore this if you're using the timeoutInterval
          // request, since the data will be truncated.

NSString* mimeType = [response MIMEType];

[fileUrlRequest release];