How to check if a file exists at particular URL?
ios, nsurlconnection, nsurlrequest, objective-c
Solution
Implement `connection:didReceiveResponse:`, which will be called before `connection:didReceiveData:`.
The response should be an `NSHTTPURLResponse` object — suppose you're issuing an HTTP request. You can therefore check `[response statusCode] == 404` to determine if the file exists or not.
See also Check if NSURL returns 404.
Problem
How do I check if a file exists on a web site? I am using `NSURLConnection` with my `NSURLRequest` and an `NSMutableData` object to store what comes back in the `didReceiveData:` delegate method. In the `connectionDidFinishingLoading:` method I then save the `NSMutableData` object to the file system. All good. Except: if the file does not exist at the website, my code still runs, gets data and saves a file. How can I check the file is there before I make download request?