Validate and Parse NSURL in Objective C

I need to check if Url is valid or not in my iPhone application so i found below snippet from  

http://stackoverflow.com

We can validate a url by simply using Foundation Framework as follows: 

        NSURL *myURL = [NSURL URLWithString:@"http://google.com"];

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

            NSLog(@"URL is validated");

        } else {

            UIAlertView *alertMsg = [[UIAlertView alloc] initWithTitle:@"Error" 

                                     message:@"URL is invalid" delegate:nil 

                                     cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];

            [alertMsg show];

            [alertMsg release];

        }

Output: 

URL is validated

Above can be achieved using RegexKit also as follows:

    NSString *regexExpression = @"(http|https)://((\\w)*|([0-9]*)|([-|_])*)+([\\.|/]((\\w)*|([0-9]*)|([-|_])*))+";

    NSString *urlString = @"http://google.com";

    

    NSString *matchedString = [urlString stringByMatching:regexExpression];

if you want to validate url string like: www.google.com just replace

(http|https):// with ((http|https)://)* 

You can download RegexKit from 

http://regexkit.sourceforge.net/

Some time we need to parse a NSURL and fetch a particular part out from it.

We can parse a NSURL as follows:

            NSURL *url = [NSURL URLWithString:@"https://www.google.co.in/search?q=validate+url+objective+c&oq=validate+url+objective+c&sugexp=chrome,mod=6&sourceid=chrome&ie=UTF-8"];

            NSLog(@"URL Scheme: %@", [url scheme]); 

            NSLog(@"URL Host: %@", [url host]); 

            NSLog(@"URL Port: %@", [url port]);     

            NSLog(@"URL Path: %@", [url path]);     

            NSLog(@"URL Relative path: %@", [url relativePath]);

            NSLog(@"URL Path components as array: %@", [url pathComponents]);        

            NSLog(@"URL Parameter string: %@", [url parameterString]);   

            NSLog(@"URL Query: %@", [url query]);       

            NSLog(@"URL Fragment: %@", [url fragment]);

Output:

 Scheme: https

 Host: www.google.co.in

 Port: (null)

 Path: /search

 Relative path: /search

 Path components as array: (

    "/",

    search

)

 Parameter string: (null)

 Query: q=validate+url+objective+c&oq=validate+url+objective+c&sugexp=chrome,mod=6&sourceid=chrome&ie=UTF-8

 Fragment: (null)