Check string containing URL for "http://"

Question

I am trying to check the URL entered by the user, but I am fighting against some errors and warnings.

-(BOOL) textFieldShouldReturn:(UITextField *)textField {
    //check "http://"
    NSString *check = textField.text;
    NSString *searchString = @"http://";
    NSRange resultRange = [check rangeWithString:searchString];
    BOOL result = resultRange.location != NSNotFound;
    if (result) {
        NSURL *urlAddress = [NSURL URLWithString: textField.text];
    } else {
        NSString *good = [NSString stringWithFormat:@"http://%@", [textField text]];
        NSURL *urlAddress = [NSURL URLWithString: good];
    }
    // open url
    NSURLRequest *requestObject = [NSURLRequest requestWithURL:urlAddress];
}

They say:

NSString may not respond to -rangeWithString
Unused variable urlAddress in the condition "if … else" (for both)
urlAddress undeclared : in the URLRequest

Does anyone have any idea what to do?

Answer 1

NSString responds to rangeOfString:, not rangeWithString:.

The variable urlAddress is declared both in the if statement, and in the else statement. That means it only lives in that scope. Once you leave the if/else statement, the variable is gone.

For a URL it's best if it begins with the scheme (like "http://"), and your code will gladly accept apple.http://.com as being valid.

You can use the hasPrefix: method instead, like this:

BOOL result = [[check lowercaseString] hasPrefix:@"http://"];
NSURL *urlAddress = nil;

if (result) {  
    urlAddress = [NSURL URLWithString: textField.text];
}
else {
    NSString *good = [NSString stringWithFormat:@"http://%@", [textField text]];
    urlAddress = [NSURL URLWithString: good];
}

NSURLRequest *requestObject = [NSURLRequest requestWithURL:urlAddress];

Answer 2

if ( [[url lowercaseString] hasPrefix:@"http://"] )
    return url;
else
    return [NSString stringWithFormat:@"http://%@", url];

Answer 3

I believe you want the rangeOfString method.

Answer 4

To get rid of your urlAddress warnings you should declare NSURL *urlAddress above if..else:

NSURL *urlAddress = nil;
if (result) {  
    urlAddress = [NSURL URLWithString: textField.text];    
} else {   
    NSString *good = [NSString stringWithFormat:@"http://%@", [textField text]];  
    urlAddress = [NSURL URLWithString: good];     
}   

Answer 5

Use this

NSString *stringUrl = url.absoluteString;

if ([stringUrl localizedCaseInsensitiveContainsString:@"your string"]) {
    //do something
}

It first converts url to string and then checks whether this url contains your string

Answer 6

If you have a NSURL convert it to NSString with

   NSString stringURL = url.absoluteString

Then check whether this NSString contains http:// with this code

 [stringURL containsString: @"http://"]


    - (BOOL)containsString:(NSString *)string {
    return [self containsString:string caseSensitive:NO];
}

- (BOOL)containsString:(NSString*)string caseSensitive:(BOOL)caseSensitive {
    BOOL contains = NO;
    if (![NSString isNilOrEmpty:self] && ![NSString isNilOrEmpty:string]) {
        NSRange range;
        if (!caseSensitive) {
            range =  [self rangeOfString:string options:NSCaseInsensitiveSearch];
        } else {
            range =  [self rangeOfString:string];
        }
        contains = (range.location != NSNotFound);
    }

    return contains;
}