"NSURL URLWithString" method not returning nil for invalid URL string

Question

I am facing an issue with "NSURL URLWithString" method,

I am expecting to get nil while using the above method if the url string is invalid. But its returning empty value instead.
I have attached the code sample below.

NSString *sampleURLString = @"";
NSURL *sampleURL = [NSURL URLWithString:sampleURLString];

NSLog(@"Sample url string : %@", sampleURLString);
NSLog(@"Sample url : %@", sampleURL);

Additional information:

I am using XCode Version 8.1.
I have also tested in iOS version (8,9,10) in device and simulator.
As of now I have handled this by using "canOpenURL" to check the resulted NSURL and avoided further execution. But I need to know why this issue occurs.

@HimanshuMoradiya : When passing any URL like "http://www.google.com" "URLWithString" function is working correctly and returning a valid NSURL, but only when I pass empty url string as above I am not getting nil as its supposed to be. — Bharath, Dec 23 '16 at 08:50
then you must have to update your question with UIwevbviewDelagates method — Himanshu Moradiya, Dec 23 '16 at 09:01
Looks strange for me as well. I assumed to use this factory method to check for correct `stringURL` passed from elsewhere: `BOOL isValidURL = ([NSURL URLWithString:baseUrl] != nil) ? YES : NO;`, but seems I can't... — Yevhen Dubinin, May 09 '17 at 20:44

score -1 · Answer 1 · answered Dec 23 '16 at 08:54

-1

Objective C

[NSURL URLWithString:[urlStr stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];

Swift

let url = NSURL(string: urlString.stringByAddingPercentEncodingWithAllowedCharacters(NSCharacterSet.URLQueryAllowedCharacterSet())!)

answered Dec 23 '16 at 08:54

Dishant Rajput

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score -2 · Answer 2 · answered Dec 23 '16 at 08:50

You are assigning an empty string. Check the length of your string to know is it empty or not.

NSString *sampleURLString = @"";
    if (sampleURLString.length <=0) {
        sampleURLString = nil;

    }
    NSURL *sampleURL = [NSURL URLWithString:sampleURLString];

    NSLog(@"Sample url string : %@", sampleURLString);
    NSLog(@"Sample url : %@", sampleURL);

Output:

Sample url string : (null)

Sample url : (null)

If you want to validate a URL

if (sampleURL && sampleURL.scheme && sampleURL.host) {

    NSLog(@"valid: %@", sampleURLString);

} else{

NSLog(@"Invalid: %@", sampleURLString);
}

"NSURL URLWithString" method not returning nil for invalid URL string

2 Answers2