Check URL validity

Question

Can someone confirm that -checkResourceIsReachableAndReturnError: method of NSURL is working as expected. I have tried using it for known URLs and it is always returning NO. I am using XCode's iPhone Simulator 4.1. Thank you.

score 5 · Accepted Answer · answered Sep 24 '10 at 23:56

5

According to NSURL Class Reference

Returns whether the resource pointed to by a file URL can be reached.
...
Discussion
This method is unimplemented in iOS, so it performs no operation

So it only works for file URLs (which your URL probably isn't) and it only works on Mac OS X anyway.

answered Sep 24 '10 at 23:56

tc.

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In conclusion, for iOS, the answer is NO, right? Any workaround? – Interfector Sep 25 '10 at 05:26
What, exactly, are you trying to achieve? – tc. Sep 26 '10 at 12:28
I want to see if I have an XML at a specific remote location – Interfector Oct 23 '10 at 11:49
You could try using NSURLConnection to access the URL and see if you get valid XML out... – tc. Nov 21 '10 at 06:11
`-checkResourceIsReachableAndReturnError:` is intended only for local files at present. You can't use it to check the existence of a remote file on any platform – Mike Abdullah Apr 09 '13 at 15:09
@MikeAbdullah Isn't that what I said? – tc. Apr 10 '13 at 14:05
Seems to be in iOS now (since 5.0): [NSURL Class Reference](http://developer.apple.com/library/ios/#documentation/Cocoa/Reference/Foundation/Classes/NSURL_Class/Reference/Reference.html) – JohnK Aug 07 '13 at 15:18

score 4 · Answer 2 · answered Dec 07 '10 at 21:12

4

You can use this method:

- (BOOL) validateUrl: (NSString *) url {
   NSString *theURL =
   @"(http|https)://((\\w)*|([0-9]*)|([-|_])*)+([\\.|/]((\\w)*|([0-9]*)|([-|_])*))+";
   NSPredicate *urlTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", theURL]; 
   return [urlTest evaluateWithObject:url];
   }

answered Dec 07 '10 at 21:12

sudo rm -rf

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This doesn't working correctly. Infant, for some valid URLs it returns NO. – Asif Bilal Feb 11 '15 at 18:20

score 1 · Answer 3 · answered May 13 '15 at 21:10

1

If you just want to know if the URL is valid, you can

NSURLRequest *req = [NSURLRequest requestWithURL:[NSURL URLWithString:@"yourstring"]];
bool valid = [NSURLConnection canHandleRequest:req];

answered May 13 '15 at 21:10

Adam Shiemke

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Check URL validity

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