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In an iPhone app I am developing, there is a setting in which you can enter a URL, because of form & function this URL needs to be validated online as well as offline.
So far I haven't been able to find any method to validate the url, so the question is;
How do I validate an URL input on the iPhone (Objective-C) online as well as offline?
Why not instead simply rely on Foundation.framework?
That does the job and does not require RegexKit :
NSURL *candidateURL = [NSURL URLWithString:candidate];
// WARNING > "test" is an URL according to RFCs, being just a path
// so you still should check scheme and all other NSURL attributes you need
if (candidateURL && candidateURL.scheme && candidateURL.host) {
// candidate is a well-formed url with:
// - a scheme (like http://)
// - a host (like stackoverflow.com)
}
According to Apple documentation :
URLWithString: Creates and returns an NSURL object initialized with a
provided string.
+ (id)URLWithString:(NSString *)URLString
Parameters
URLString : The string with which to initialize the NSURL object. Must conform to RFC 2396. This method parses URLString according to RFCs 1738 and 1808.
Return Value
An NSURL object initialized with URLString. If the string was malformed, returns nil.
Thanks to this post, you can avoid using RegexKit.
Here is my solution (works for iphone development with iOS > 3.0) :
- (BOOL) validateUrl: (NSString *) candidate {
NSString *urlRegEx =
#"(http|https)://((\\w)*|([0-9]*)|([-|_])*)+([\\.|/]((\\w)*|([0-9]*)|([-|_])*))+";
NSPredicate *urlTest = [NSPredicate predicateWithFormat:#"SELF MATCHES %#", urlRegEx];
return [urlTest evaluateWithObject:candidate];
}
If you want to check in Swift my solution given below:
func isValidUrl(url: String) -> Bool {
let urlRegEx = "^(https?://)?(www\\.)?([-a-z0-9]{1,63}\\.)*?[a-z0-9][-a-z0-9]{0,61}[a-z0-9]\\.[a-z]{2,6}(/[-\\w#\\+\\.~#\\?&/=%]*)?$"
let urlTest = NSPredicate(format:"SELF MATCHES %#", urlRegEx)
let result = urlTest.evaluate(with: url)
return result
}
Instead of writing your own regular expressions, rely on Apple's. I have been using a category on NSString that uses NSDataDetector to test for the presence of a link within a string. If the range of the link found by NSDataDetector equals the length of the entire string, then it is a valid URL.
- (BOOL)isValidURL {
NSUInteger length = [self length];
// Empty strings should return NO
if (length > 0) {
NSError *error = nil;
NSDataDetector *dataDetector = [NSDataDetector dataDetectorWithTypes:NSTextCheckingTypeLink error:&error];
if (dataDetector && !error) {
NSRange range = NSMakeRange(0, length);
NSRange notFoundRange = (NSRange){NSNotFound, 0};
NSRange linkRange = [dataDetector rangeOfFirstMatchInString:self options:0 range:range];
if (!NSEqualRanges(notFoundRange, linkRange) && NSEqualRanges(range, linkRange)) {
return YES;
}
}
else {
NSLog(#"Could not create link data detector: %# %#", [error localizedDescription], [error userInfo]);
}
}
return NO;
}
My solution with Swift:
func validateUrl (stringURL : NSString) -> Bool {
var urlRegEx = "((https|http)://)((\\w|-)+)(([.]|[/])((\\w|-)+))+"
let predicate = NSPredicate(format:"SELF MATCHES %#", argumentArray:[urlRegEx])
var urlTest = NSPredicate.predicateWithSubstitutionVariables(predicate)
return predicate.evaluateWithObject(stringURL)
}
For Test:
var boolean1 = validateUrl("http.s://www.gmail.com")
var boolean2 = validateUrl("https:.//gmailcom")
var boolean3 = validateUrl("https://gmail.me.")
var boolean4 = validateUrl("https://www.gmail.me.com.com.com.com")
var boolean6 = validateUrl("http:/./ww-w.wowone.com")
var boolean7 = validateUrl("http://.www.wowone")
var boolean8 = validateUrl("http://www.wow-one.com")
var boolean9 = validateUrl("http://www.wow_one.com")
var boolean10 = validateUrl("http://.")
var boolean11 = validateUrl("http://")
var boolean12 = validateUrl("http://k")
Results:
false
false
false
true
false
false
true
true
false
false
false
use this-
NSString *urlRegEx = #"http(s)?://([\\w-]+\\.)+[\\w-]+(/[\\w- ./?%&=]*)?";
I solved the problem using RegexKit, and build a quick regex to validate a URL;
NSString *regexString = #"(http|https)://((\\w)*|([0-9]*)|([-|_])*)+([\\.|/]((\\w)*|([0-9]*)|([-|_])*))+";
NSString *subjectString = brandLink.text;
NSString *matchedString = [subjectString stringByMatching:regexString];
Then I check if the matchedString is equal to the subjectString and if that is the case the url is valid :)
Correct me if my regex is wrong ;)
I've found the easiest way to do this is like so:
- (BOOL)validateUrl: (NSURL *)candidate
{
NSURLRequest *req = [NSURLRequest requestWithURL:candidate];
return [NSURLConnection canHandleRequest:req];
}
Oddly enough, I didn't really find a solution here that was very simple, yet still did an okay job for handling http / https links.
Keep in mind, THIS IS NOT a perfect solution, but it worked for the cases below. In summary, the regex tests whether the URL starts with http:// or https://, then checks for at least 1 character, then checks for a dot, and then again checks for at least 1 character. No spaces allowed.
+ (BOOL)validateLink:(NSString *)link
{
NSString *regex = #"(?i)(http|https)(:\\/\\/)([^ .]+)(\\.)([^ \n]+)";
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"SELF MATCHES %#", regex];
return [predicate evaluateWithObject:link];
}
Tested VALID against these URLs:
#"HTTP://FOO.COM",
#"HTTPS://FOO.COM",
#"http://foo.com/blah_blah",
#"http://foo.com/blah_blah/",
#"http://foo.com/blah_blah_(wikipedia)",
#"http://foo.com/blah_blah_(wikipedia)_(again)",
#"http://www.example.com/wpstyle/?p=364",
#"https://www.example.com/foo/?bar=baz&inga=42&quux",
#"http://✪df.ws/123",
#"http://userid:password#example.com:8080",
#"http://userid:password#example.com:8080/",
#"http://userid#example.com",
#"http://userid#example.com/",
#"http://userid#example.com:8080",
#"http://userid#example.com:8080/",
#"http://userid:password#example.com",
#"http://userid:password#example.com/",
#"http://142.42.1.1/",
#"http://142.42.1.1:8080/",
#"http://➡.ws/䨹",
#"http://⌘.ws",
#"http://⌘.ws/",
#"http://foo.com/blah_(wikipedia)#cite-",
#"http://foo.com/blah_(wikipedia)_blah#cite-",
#"http://foo.com/unicode_(✪)_in_parens",
#"http://foo.com/(something)?after=parens",
#"http://☺.damowmow.com/",
#"http://code.google.com/events/#&product=browser",
#"http://j.mp",
#"http://foo.bar/?q=Test%20URL-encoded%20stuff",
#"http://مثال.إختبار",
#"http://例子.测试",
#"http://उदाहरण.परीक्षा",
#"http://-.~_!$&'()*+,;=:%40:80%2f::::::#example.com",
#"http://1337.net",
#"http://a.b-c.de",
#"http://223.255.255.254"
Tested INVALID against these URLs:
#"",
#"foo",
#"ftp://foo.com",
#"ftp://foo.com",
#"http://..",
#"http://..",
#"http://../",
#"//",
#"///",
#"http://##/",
#"http://.www.foo.bar./",
#"rdar://1234",
#"http://foo.bar?q=Spaces should be encoded",
#"http:// shouldfail.com",
#":// should fail"
Source of URLs:
https://mathiasbynens.be/demo/url-regex
You can use this if you do not want http or https or www
NSString *urlRegEx = #"^(http(s)?://)?((www)?\.)?[\w]+\.[\w]+";
example
- (void) testUrl:(NSString *)urlString{
NSLog(#"%#: %#", ([self isValidUrl:urlString] ? #"VALID" : #"INVALID"), urlString);
}
- (void)doTestUrls{
[self testUrl:#"google"];
[self testUrl:#"google.de"];
[self testUrl:#"www.google.de"];
[self testUrl:#"http://www.google.de"];
[self testUrl:#"http://google.de"];
}
Output:
INVALID: google
VALID: google.de
VALID: www.google.de
VALID: http://www.google.de
VALID: http://google.de
Lefakir's solution has one issue.
His regex can't match with "http://instagram.com/p/4Mz3dTJ-ra/".
Url component has combined numerical and literal character. His regex fail such urls.
Here is my improvement.
"(http|https)://((\\w)*|([0-9]*)|([-|_])*)+([\\.|/]((\\w)*|([0-9]*)|([-|_])*)+)+(/)?(\\?.*)?"
Below code will let you find the valid URLs
NSPredicate *websitePredicate = [NSPredicate predicateWithFormat:#"SELF MATCHES %#",#"^(((((h|H)(t|T){2}(p|P)s?)|((f|F)(t|T)(p|P)))://(w{3}.)?)|(w{3}.))[A-Za-z0-9]+(.[A-Za-z0-9-:;\?#_]+)+"];
if ([websitePredicate evaluateWithObject:##MY_STRING##])
{
printf"Valid"
}
for such URLS
http://123.com
https://123.com
http://www.123.com
https://www.123.com
ftp://123.com
ftp://www.123.com
www.something.com
The approved answer is incorrect.
I have an URL with an "-" in it, and the validation fails.
Tweeked Vaibhav's answer to support G+ links:
NSString *urlRegEx = #"http(s)?://([\\w-]+\\.)+[\\w-]+(/[\\w-\\+ ./?%&=]*)?";
Some URL's without / at the end are not detected as the correct one in the solutions above. So this might be helpful.
extension String {
func isValidURL() -> Bool{
let length:Int = self.characters.count
var err:NSError?
var dataDetector:NSDataDetector? = NSDataDetector()
do{
dataDetector = try NSDataDetector(types: NSTextCheckingType.Link.rawValue)
}catch{
err = error as NSError
}
if dataDetector != nil{
let range = NSMakeRange(0, length)
let notFoundRange = NSRange(location: NSNotFound, length: 0)
let linkRange = dataDetector?.rangeOfFirstMatchInString(self, options: NSMatchingOptions.init(rawValue: 0), range: range)
if !NSEqualRanges(notFoundRange, linkRange!) && NSEqualRanges(range, linkRange!){
return true
}
}else{
print("Could not create link data detector: \(err?.localizedDescription): \(err?.userInfo)")
}
return false
}
}
URL Validation in Swift
Details
Xcode 8.2.1, Swift 3
Code
enum URLSchemes: String
import Foundation
enum URLSchemes: String {
case http = "http://", https = "https://", ftp = "ftp://", unknown = "unknown://"
static func detectScheme(urlString: String) -> URLSchemes {
if URLSchemes.isSchemeCorrect(urlString: urlString, scheme: .http) {
return .http
}
if URLSchemes.isSchemeCorrect(urlString: urlString, scheme: .https) {
return .https
}
if URLSchemes.isSchemeCorrect(urlString: urlString, scheme: .ftp) {
return .ftp
}
return .unknown
}
static func getAllSchemes(separetedBy separator: String) -> String {
return "\(URLSchemes.http.rawValue)\(separator)\(URLSchemes.https.rawValue)\(separator)\(URLSchemes.ftp.rawValue)"
}
private static func isSchemeCorrect(urlString: String, scheme: URLSchemes) -> Bool {
if urlString.replacingOccurrences(of: scheme.rawValue, with: "") == urlString {
return false
}
return true
}
}
extension String
import Foundation
extension String {
var isUrl: Bool {
// for http://regexr.com checking
// (?:(?:https?|ftp):\/\/)(?:xn--)?(?:\S+(?::\S*)?#)?(?:(?!10(?:\.\d{1,3}){3})(?!127(?:\.\d{1,3}){3})(?!169\.254(?:\.\d{1,3}){2})(?!192\.168(?:\.\d{1,3}){2})(?!172\.(?:1[6-9]|2\d|3[0-1])(?:\.\d{1,3}){2})(?:[1-9]\d?|1\d\d|2[01]\d|22[0-3])(?:\.(?:1?\d{1,2}|2[0-4]\d|25[0-5])){2}(?:\.(?:[1-9]\d?|1\d\d|2[0-4]\d|25[0-4]))|(?:(?:[a-z\u00a1-\uffff0-9]+-?)*[a-z\u00a1-\uffff0-9]+)(?:\.(?:[a-z\u00a1-\uffff0-9]+-?)*[a-z\u00a1-\uffff0-9]+)*(?:\.(?:[#-z\u00a1-\uffff]{2,})))(?::\d{2,5})?(?:\/[^\s]*)?
let schemes = URLSchemes.getAllSchemes(separetedBy: "|").replacingOccurrences(of: "://", with: "")
let regex = "(?:(?:\(schemes)):\\/\\/)(?:xn--)?(?:\\S+(?::\\S*)?#)?(?:(?!10(?:\\.\\d{1,3}){3})(?!127(?:\\.\\d{1,3}){3})(?!169\\.254(?:\\.\\d{1,3}){2})(?!192\\.168(?:\\.\\d{1,3}){2})(?!172\\.(?:1[6-9]|2\\d|3[0-1])(?:\\.\\d{1,3}){2})(?:[1-9]\\d?|1\\d\\d|2[01]\\d|22[0-3])(?:\\.(?:1?\\d{1,2}|2[0-4]\\d|25[0-5])){2}(?:\\.(?:[1-9]\\d?|1\\d\\d|2[0-4]\\d|25[0-4]))|(?:(?:[a-z\\u00a1-\\uffff0-9]+-?)*[a-z\\u00a1-\\uffff0-9]+)(?:\\.(?:[a-z\\u00a1-\\uffff0-9]+-?)*[a-z\\u00a1-\\uffff0-9]+)*(?:\\.(?:[#-z\\u00a1-\\uffff]{2,})))(?::\\d{2,5})?(?:\\/[^\\s]*)?"
let regularExpression = try! NSRegularExpression(pattern: regex, options: [])
let range = NSRange(location: 0, length: self.characters.count)
let matches = regularExpression.matches(in: self, options: [], range: range)
for match in matches {
if range.location == match.range.location && range.length == match.range.length {
return true
}
}
return false
}
var toURL: URL? {
let urlChecker: (String)->(URL?) = { url_string in
if url_string.isUrl, let url = URL(string: url_string) {
return url
}
return nil
}
if !contains(".") {
return nil
}
if let url = urlChecker(self) {
return url
}
let scheme = URLSchemes.detectScheme(urlString: self)
if scheme == .unknown {
let newEncodedString = URLSchemes.http.rawValue + self
if let url = urlChecker(newEncodedString) {
return url
}
}
return nil
}
}
Usage
func tests() {
chekUrl(urlString:"http://example.com")
chekUrl(urlString:"https://example.com")
chekUrl(urlString:"http://example.com/dir/file.php?var=moo")
chekUrl(urlString:"http://xn--h1aehhjhg.xn--d1acj3b")
chekUrl(urlString:"http://www.example.com/wpstyle/?p=364")
chekUrl(urlString:"http://-.~_!$&'()*+,;=:%40:80%2f::::::#example.com")
chekUrl(urlString:"http://example.com")
chekUrl(urlString:"http://xn--d1acpjx3f.xn--p1ai")
chekUrl(urlString:"http://xn--74h.damowmow.com/")
chekUrl(urlString:"ftp://example.com:129/myfiles")
chekUrl(urlString:"ftp://user:pass#site.com:21/file/dir")
chekUrl(urlString:"ftp://ftp.example.com:2828/asdah%20asdah.gif")
chekUrl(urlString:"http://142.42.1.1:8080/")
chekUrl(urlString:"http://142.42.1.1/")
chekUrl(urlString:"http://userid:password#example.com:8080")
chekUrl(urlString:"http://userid#example.com")
chekUrl(urlString:"http://userid#example.com:8080")
chekUrl(urlString:"http://foo.com/blah_(wikipedia)#cite-1")
chekUrl(urlString:"http://foo.com/(something)?after=parens")
print("\n----------------------------------------------\n")
chekUrl(urlString:".")
chekUrl(urlString:" ")
chekUrl(urlString:"")
chekUrl(urlString:"-/:;()₽&#.,?!'{}[];'<>+_)(*#^%$")
chekUrl(urlString:"localhost")
chekUrl(urlString:"yandex.")
chekUrl(urlString:"коряга")
chekUrl(urlString:"http:///a")
chekUrl(urlString:"ftps://foo.bar/")
chekUrl(urlString:"rdar://1234")
chekUrl(urlString:"h://test")
chekUrl(urlString:":// should fail")
chekUrl(urlString:"http://-error-.invalid/")
chekUrl(urlString:"http://.www.example.com/")
}
func chekUrl(urlString: String) {
var result = ""
if urlString.isUrl {
result += "url: "
} else {
result += "not url: "
}
result += "\"\(urlString)\""
print(result)
}
Result
Objective C
- (BOOL)validateUrlString:(NSString*)urlString
{
if (!urlString)
{
return NO;
}
NSDataDetector *linkDetector = [NSDataDetector dataDetectorWithTypes:NSTextCheckingTypeLink error:nil];
NSRange urlStringRange = NSMakeRange(0, [urlString length]);
NSMatchingOptions matchingOptions = 0;
if (1 != [linkDetector numberOfMatchesInString:urlString options:matchingOptions range:urlStringRange])
{
return NO;
}
NSTextCheckingResult *checkingResult = [linkDetector firstMatchInString:urlString options:matchingOptions range:urlStringRange];
return checkingResult.resultType == NSTextCheckingTypeLink && NSEqualRanges(checkingResult.range, urlStringRange);
}
Hope this helps!
did you mean to check if what the user entered is a URL? It can be as simple as a regular expression, for example checking if the string contain www. (this is the way that yahoo messenger checks if the user status is a link or not)
Hope that help
Selfishly, I would suggest using a KSURLFormatter instance to both validate input, and convert it to something NSURL can handle.
I have created inherited class of UITextField which can handle all kind of validation using regex string. In this you just need to give them all the regex string in sequence and their message that you want to show when validation get failed. You can check my blog for more info, it will really help you
http://dhawaldawar.wordpress.com/2014/06/11/uitextfield-validation-ios/
Extending #Anthony's answer to swift, I wrote a category on String which returns an optional NSURL. The return value is nil if the String can not be validated to be a URL.
import Foundation
// A private global detector variable which can be reused.
private let detector = try! NSDataDetector(types: NSTextCheckingType.Link.rawValue)
extension String {
func URL() -> NSURL? {
let textRange = NSMakeRange(0, self.characters.count)
guard let URLResult = detector.firstMatchInString(self, options: [], range: textRange) else {
return nil
}
// This checks that the whole string is the detected URL. In case
// you don't have such a requirement, you can remove this code
// and return the URL from URLResult.
guard NSEqualRanges(URLResult.range, textRange) else {
return nil
}
return NSURL(string: self)
}
}
func checkValidUrl(_ strUrl: String) -> Bool {
let urlRegEx: String = "(http|https)://((\\w)*|([0-9]*)|([-|_])*)+([\\.|/]((\\w)*|([0-9]*)|([-|_])*))+"
let urlTest = NSPredicate(format: "SELF MATCHES %#", urlRegEx)
return urlTest.evaluate(with: strUrl)
}
My solution in Swift 5:
extension String {
func isValidUrl() -> Bool {
do {
let detector = try NSDataDetector(types: NSTextCheckingResult.CheckingType.link.rawValue)
// check if the string has link inside
return detector.numberOfMatches(in: self, options: [], range: .init( location: 0, length: utf16.count)) > 0
} catch {
print("Error during NSDatadetector initialization \(error)" )
}
return false
}
}
I stumbled upon this piece of Objective-C code:
- (void)updateUser:(NSDictionary<FBGraphUser> *)user inSlot:(NSInteger)slot {
[self validateSlotNumber:slot];
NSString *idKey = [NSString stringWithFormat:SUUserIDKeyFormat, (long)slot];
NSString *nameKey = [NSString stringWithFormat:SUUserNameKeyFormat, (long)slot];
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
if (user != nil) {
NSLog(#"SUUserManager updating slot %li: fbid = %#, name = %#", (long)slot, user.objectID, user.name);
[defaults setObject:user.objectID forKey:idKey];
[defaults setObject:user.name forKey:nameKey];
} else {
NSLog(#"SUUserManager clearing slot %li", (long)slot);
// Can't be current user anymore
if (slot == _currentUserSlot) {
[self switchToNoActiveUser];
}
// FBSample logic
// Also need to tell the token cache to forget the tokens for this user
FBSessionTokenCachingStrategy *tokenCachingStrategy = [self createCachingStrategyForSlot:slot];
[tokenCachingStrategy clearToken];
[defaults removeObjectForKey:idKey];
[defaults removeObjectForKey:nameKey];
}
[defaults synchronize];
[self sendNotification];
}
It is from one of the Facebook iOS SDK examples. I am trying to use it in my Swift written app. This is what I come up with:
func updateUser(user: Dictionary<String, FBGraphUser>, slot: Int) {
var idKey: String = String(format: userIDKeyFormat, slot)
var nameKey: String = String(format: userNameKeyFormat, slot)
var defaults: NSUserDefaults = NSUserDefaults.standardUserDefaults()
if(user != nil) {
println("UserManager updating slot \(slot): Facebook ID = \(user.objectID), Name = \(user.name)")
defaults.setObject(user.objectID, forKey: idKey)
defaults.setObject(user.name, forKey: nameKey)
} else {
println("UserManager clearing slot \(slot)")
if(slot == currentUserSlot) {
self.switchToNoActiveUser()
}
var tokenCachingStrategy: FBSessionTokenCachingStrategy = self.createCachingStrategyForSlot(slot)
tokenCachingStrategy.clearToken()
defaults.removeObjectForKey(idKey)
defaults.removeObjectForKey(nameKey)
}
defaults.synchronize()
self.sendNotification()
}
The problem is in Dictionary<String, FBGraphUser> which, I think, is just not the same as the Obj-C equivalent. In the if statement to check if user is not nil, Xcode throws an error: 'Dictionary' is not convertible to 'String'.
So how do I translate the Obj-C code to Swift?
Thanks!
You have to set you dictionary as an optional:
func updateUser(user: Dictionary<String, FBGraphUser>?, slot: Int) {...}
After some extensive research I finally found a way:
func updateUser<val: NSDictionary where val:protocol<FBGraphUser>>(user:val!, slot: Int) {
var idKey: String = String(format: userIDKeyFormat, slot)
var nameKey: String = String(format: userNameKeyFormat, slot)
var defaults: NSUserDefaults = NSUserDefaults.standardUserDefaults()
if(user != nil) {
println("UserManager updating slot \(slot): Facebook ID = \(user!.objectID), Name = \(user!.name)")
defaults.setObject(user!.objectID, forKey: idKey)
defaults.setObject(user!.name, forKey: nameKey)
} else {
println("UserManager clearing slot \(slot)")
if(slot == currentUserSlot) {
self.switchToNoActiveUser()
}
var tokenCachingStrategy: FBSessionTokenCachingStrategy = self.createCachingStrategyForSlot(slot)
tokenCachingStrategy.clearToken()
defaults.removeObjectForKey(idKey)
defaults.removeObjectForKey(nameKey)
}
defaults.synchronize()
self.sendNotification()
}
Simple and may asked many time but little trick with this. We know, NSString doesn't work with case sensitivity for hasPrefix: method.
NSString *string = #"Xyzabcdedfghij";
NSString *substring = #"xyz";
if ([string hasPrefix:substring])
NSLog(#"string has prefix "); // won't get here.
Question is: Is there any built-in method for resolve this issue? I mean, hasPrefix: with case sensitive?
I could use below answer at least case. But want to know if there is any method which better than this..?
Known answer:(lease case)
if ([[test substringWithRange:NSMakeRange(0,3)] caseInsensitiveCompare:#"xyz"] == NSOrderedSame) {
// ....
}
From Apple themselves:
NSString *searchString = #"age";
NSString *beginsTest = #"Agencies";
NSRange prefixRange = [beginsTest rangeOfString:searchString
options:(NSAnchoredSearch | NSCaseInsensitiveSearch)];
// prefixRange = {0, 3}
NSString *endsTest = #"BRICOLAGE";
NSRange suffixRange = [endsTest rangeOfString:searchString
options:(NSAnchoredSearch | NSCaseInsensitiveSearch | NSBackwardsSearch)];
// suffixRange = {6, 3}
This could be wrapped into an easy-to-use method:
- (BOOL) string:(NSString *)string
hasPrefix:(NSString *)prefix
caseInsensitive:(BOOL)caseInsensitive {
if (!caseInsensitive)
return [string hasPrefix:prefix];
const NSStringCompareOptions options = NSAnchoredSearch|NSCaseInsensitiveSearch;
NSRange prefixRange = [string rangeOfString:prefix
options:options];
return prefixRange.location == 0 && prefixRange.length > 0;
}
You can always use lowercaseString on both strings and thus forcing the same case. So for example
[[string lowercaseString] hasPrefix:[substring lowercaseString]];
Nasty way to do is to lower case the both string and than use hasPrefix
e.g.
[[mainString lowercaseString] hasPrefix:[stringToFind lowercaseString]];
Swift 5:
extension String {
public func hasPrefixIgnoringCase(_ prefix: String) -> Bool {
range(of: prefix, options: [.anchored, .caseInsensitive]) != nil
}
}
Usage:
"Hello".hasPrefixIgnoringCase("hEl") // return true
you can do this by
if([[string lowercaseString] hasPrefix:[substring lowercaseString]])
{
NSLog(#"found");
}
A Swift 4.2 version of accepted answer:
extension String {
public func hasPrefix<Prefix>(_ prefix: Prefix, caseSensitive: Bool) -> Bool where Prefix : StringProtocol {
if caseSensitive { return self.hasPrefix(prefix) }
let prefixRange = self.range(of: prefix, options: [.anchored, .caseInsensitive])
return prefixRange != nil
}
}
Alternatively, using .lowercased()
extension String {
public func hasPrefix<Prefix>(_ prefix: Prefix, caseSensitive: Bool) -> Bool where Prefix : StringProtocol {
if caseSensitive { return self.hasPrefix(prefix) }
return self.lowercased().hasPrefix(prefix.lowercased())
}
}
The extension is to use as following
let string = "Hello World"
let caseSensitiveSearch = string.hasPrefix("hello", caseSensitive: true) // return false
let caseNotSensitiveSearch = string.hasPrefix("hello", caseSensitive: false) // return true
For those of you who like functional style one-liners (like I do):
extension String {
func hasPrefix<Prefix>(_ prefix: Prefix, caseSensitive: Bool) -> Bool where Prefix: StringProtocol {
return caseSensitive ? hasPrefix(prefix) :
self.range(of: prefix, options: [.anchored, .caseInsensitive]) != nil
}
}
Swift 5
extension StringProtocol {
public func hasPrefix<T: StringProtocol>(caseInsensitive prefix: T) -> Bool {
lowercased().starts(with: prefix.lowercased())
}
}
Use:
"Hello World".hasPrefix(caseInsensitive: "hello") //true
I'm using the following function in order to get all the keys and values of the preferences.plist file located in: /private/var/preferences/SystemConfiguration/preferences.plist
- (void)FindKeysAndValuesInPlist:(id)object forKeyNamed:(NSString *)keyName{
if ([object isKindOfClass:[NSDictionary class]])
{
NSLog(#"%#",keyName);
[object enumerateKeysAndObjectsUsingBlock:^(id key, id value, BOOL *stop) {
[self FindKeysAndValuesInPlist:value forKeyNamed:key];
}];
}
else if ([object isKindOfClass:[NSArray class]])
{
[object enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
[self FindKeysAndValuesInPlist:obj forKeyNamed:nil];
}];
}
else
{
NSLog(#"%#.%#", keyName, object);
}
}
An example of the content of preferences.plist:
{
CurrentSet = "/Sets/3B9E7BEB-5558-4497-803B-21B03E6A46C0";
NetworkServices = {
"014226AB-75B7-41CF-9B96-48E82FD6A395" = {
Interface = {
DeviceName = ip4;
Hardware = "com.apple.CommCenter";
Type = "com.apple.CommCenter";
UserDefinedName = "com.apple.CommCenter (ip4)";
};
PrimaryRank = Never;
UserDefinedName = "com.apple.CommCenter (ip4)";
"com.apple.CommCenter" = {
AllowNetworkAccess = 0;
Available = 1;
Version = 11;
};
};
"1C01B561-1A55-4E3B-82FC-CDFF5024F0D2" = {
Interface = {
DeviceName = ip1;
Hardware = "com.apple.CommCenter";
Type = "com.apple.CommCenter";
UserDefinedName = "com.apple.CommCenter (ip1)";
};
UserDefinedName = "com.apple.CommCenter (ip1)";
"com.apple.CommCenter" = {
AllowNetworkAccess = 1;
Available = 1;
SettingsHaveBeenAlteredByPreferences = 1;
Setup = {
apn = "";
password = "";
signature = <7ecb277c ad546563 3ac057fb db40aeaa 939f8c0e e7ae68c2 6e0ff602 77d3868d 18a63059 6c83f66d 46b8af57 d1bf83d0 2655ced6 57d773f4 5c7e733e 923aaa07 39165357 a4ecf270 130276f0 59c7470e 0b61a631 dff04fd1 0bc80cb4 a0dc0a03 96a8ebf0 74c24cdb 84c38239 9f6f7f05 ee032982 8ed1b72d b531405b 09e35f5b>;
"type-mask" = 0;
username = "";
};
Version = 11;
};
};
The problem is that I'm trying to create this kind of output format: MAINKEY.SUBKEY.VALUE
For example:
NetworkServices = {
"014226AB-75B7-41CF-9B96-48E82FD6A395" = {
Interface = {
DeviceName = ip4;
Hardware = "com.apple.CommCenter";
Type = "com.apple.CommCenter";
UserDefinedName = "com.apple.CommCenter (ip4)";
};
Would be: NetworkServices.014226AB-75B7-41CF-9B96-48E82FD6A395.Interface.Hardware.ip4
Iterate over the keys in a dictionary. When the value for a key is another dictionary, push the key onto a stack and recurse on the dictionary value. When the value is a string or number, then concatenate the keys in the stack and print the key path and value.
Code:
+ (void)printDict:(NSDictionary *)dict keyStack:(NSArray *)keys
{
if (keys == nil) {
keys = [NSArray array];
}
for (id key in dict) {
id value = dict[key];
if ([value respondsToSelector:#selector(objectForKey:)]) {
[self printDict:value keyStack:[keys arrayByAddingObject:key]];
} else {
NSLog(#"%# = %#", [[keys arrayByAddingObject:key] componentsJoinedByString:#"."], value);
}
}
}
In an iPhone app I am developing, there is a setting in which you can enter a URL, because of form & function this URL needs to be validated online as well as offline.
So far I haven't been able to find any method to validate the url, so the question is;
How do I validate an URL input on the iPhone (Objective-C) online as well as offline?
Why not instead simply rely on Foundation.framework?
That does the job and does not require RegexKit :
NSURL *candidateURL = [NSURL URLWithString:candidate];
// WARNING > "test" is an URL according to RFCs, being just a path
// so you still should check scheme and all other NSURL attributes you need
if (candidateURL && candidateURL.scheme && candidateURL.host) {
// candidate is a well-formed url with:
// - a scheme (like http://)
// - a host (like stackoverflow.com)
}
According to Apple documentation :
URLWithString: Creates and returns an NSURL object initialized with a
provided string.
+ (id)URLWithString:(NSString *)URLString
Parameters
URLString : The string with which to initialize the NSURL object. Must conform to RFC 2396. This method parses URLString according to RFCs 1738 and 1808.
Return Value
An NSURL object initialized with URLString. If the string was malformed, returns nil.
Thanks to this post, you can avoid using RegexKit.
Here is my solution (works for iphone development with iOS > 3.0) :
- (BOOL) validateUrl: (NSString *) candidate {
NSString *urlRegEx =
#"(http|https)://((\\w)*|([0-9]*)|([-|_])*)+([\\.|/]((\\w)*|([0-9]*)|([-|_])*))+";
NSPredicate *urlTest = [NSPredicate predicateWithFormat:#"SELF MATCHES %#", urlRegEx];
return [urlTest evaluateWithObject:candidate];
}
If you want to check in Swift my solution given below:
func isValidUrl(url: String) -> Bool {
let urlRegEx = "^(https?://)?(www\\.)?([-a-z0-9]{1,63}\\.)*?[a-z0-9][-a-z0-9]{0,61}[a-z0-9]\\.[a-z]{2,6}(/[-\\w#\\+\\.~#\\?&/=%]*)?$"
let urlTest = NSPredicate(format:"SELF MATCHES %#", urlRegEx)
let result = urlTest.evaluate(with: url)
return result
}
Instead of writing your own regular expressions, rely on Apple's. I have been using a category on NSString that uses NSDataDetector to test for the presence of a link within a string. If the range of the link found by NSDataDetector equals the length of the entire string, then it is a valid URL.
- (BOOL)isValidURL {
NSUInteger length = [self length];
// Empty strings should return NO
if (length > 0) {
NSError *error = nil;
NSDataDetector *dataDetector = [NSDataDetector dataDetectorWithTypes:NSTextCheckingTypeLink error:&error];
if (dataDetector && !error) {
NSRange range = NSMakeRange(0, length);
NSRange notFoundRange = (NSRange){NSNotFound, 0};
NSRange linkRange = [dataDetector rangeOfFirstMatchInString:self options:0 range:range];
if (!NSEqualRanges(notFoundRange, linkRange) && NSEqualRanges(range, linkRange)) {
return YES;
}
}
else {
NSLog(#"Could not create link data detector: %# %#", [error localizedDescription], [error userInfo]);
}
}
return NO;
}
My solution with Swift:
func validateUrl (stringURL : NSString) -> Bool {
var urlRegEx = "((https|http)://)((\\w|-)+)(([.]|[/])((\\w|-)+))+"
let predicate = NSPredicate(format:"SELF MATCHES %#", argumentArray:[urlRegEx])
var urlTest = NSPredicate.predicateWithSubstitutionVariables(predicate)
return predicate.evaluateWithObject(stringURL)
}
For Test:
var boolean1 = validateUrl("http.s://www.gmail.com")
var boolean2 = validateUrl("https:.//gmailcom")
var boolean3 = validateUrl("https://gmail.me.")
var boolean4 = validateUrl("https://www.gmail.me.com.com.com.com")
var boolean6 = validateUrl("http:/./ww-w.wowone.com")
var boolean7 = validateUrl("http://.www.wowone")
var boolean8 = validateUrl("http://www.wow-one.com")
var boolean9 = validateUrl("http://www.wow_one.com")
var boolean10 = validateUrl("http://.")
var boolean11 = validateUrl("http://")
var boolean12 = validateUrl("http://k")
Results:
false
false
false
true
false
false
true
true
false
false
false
use this-
NSString *urlRegEx = #"http(s)?://([\\w-]+\\.)+[\\w-]+(/[\\w- ./?%&=]*)?";
I solved the problem using RegexKit, and build a quick regex to validate a URL;
NSString *regexString = #"(http|https)://((\\w)*|([0-9]*)|([-|_])*)+([\\.|/]((\\w)*|([0-9]*)|([-|_])*))+";
NSString *subjectString = brandLink.text;
NSString *matchedString = [subjectString stringByMatching:regexString];
Then I check if the matchedString is equal to the subjectString and if that is the case the url is valid :)
Correct me if my regex is wrong ;)
I've found the easiest way to do this is like so:
- (BOOL)validateUrl: (NSURL *)candidate
{
NSURLRequest *req = [NSURLRequest requestWithURL:candidate];
return [NSURLConnection canHandleRequest:req];
}
Oddly enough, I didn't really find a solution here that was very simple, yet still did an okay job for handling http / https links.
Keep in mind, THIS IS NOT a perfect solution, but it worked for the cases below. In summary, the regex tests whether the URL starts with http:// or https://, then checks for at least 1 character, then checks for a dot, and then again checks for at least 1 character. No spaces allowed.
+ (BOOL)validateLink:(NSString *)link
{
NSString *regex = #"(?i)(http|https)(:\\/\\/)([^ .]+)(\\.)([^ \n]+)";
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"SELF MATCHES %#", regex];
return [predicate evaluateWithObject:link];
}
Tested VALID against these URLs:
#"HTTP://FOO.COM",
#"HTTPS://FOO.COM",
#"http://foo.com/blah_blah",
#"http://foo.com/blah_blah/",
#"http://foo.com/blah_blah_(wikipedia)",
#"http://foo.com/blah_blah_(wikipedia)_(again)",
#"http://www.example.com/wpstyle/?p=364",
#"https://www.example.com/foo/?bar=baz&inga=42&quux",
#"http://✪df.ws/123",
#"http://userid:password#example.com:8080",
#"http://userid:password#example.com:8080/",
#"http://userid#example.com",
#"http://userid#example.com/",
#"http://userid#example.com:8080",
#"http://userid#example.com:8080/",
#"http://userid:password#example.com",
#"http://userid:password#example.com/",
#"http://142.42.1.1/",
#"http://142.42.1.1:8080/",
#"http://➡.ws/䨹",
#"http://⌘.ws",
#"http://⌘.ws/",
#"http://foo.com/blah_(wikipedia)#cite-",
#"http://foo.com/blah_(wikipedia)_blah#cite-",
#"http://foo.com/unicode_(✪)_in_parens",
#"http://foo.com/(something)?after=parens",
#"http://☺.damowmow.com/",
#"http://code.google.com/events/#&product=browser",
#"http://j.mp",
#"http://foo.bar/?q=Test%20URL-encoded%20stuff",
#"http://مثال.إختبار",
#"http://例子.测试",
#"http://उदाहरण.परीक्षा",
#"http://-.~_!$&'()*+,;=:%40:80%2f::::::#example.com",
#"http://1337.net",
#"http://a.b-c.de",
#"http://223.255.255.254"
Tested INVALID against these URLs:
#"",
#"foo",
#"ftp://foo.com",
#"ftp://foo.com",
#"http://..",
#"http://..",
#"http://../",
#"//",
#"///",
#"http://##/",
#"http://.www.foo.bar./",
#"rdar://1234",
#"http://foo.bar?q=Spaces should be encoded",
#"http:// shouldfail.com",
#":// should fail"
Source of URLs:
https://mathiasbynens.be/demo/url-regex
You can use this if you do not want http or https or www
NSString *urlRegEx = #"^(http(s)?://)?((www)?\.)?[\w]+\.[\w]+";
example
- (void) testUrl:(NSString *)urlString{
NSLog(#"%#: %#", ([self isValidUrl:urlString] ? #"VALID" : #"INVALID"), urlString);
}
- (void)doTestUrls{
[self testUrl:#"google"];
[self testUrl:#"google.de"];
[self testUrl:#"www.google.de"];
[self testUrl:#"http://www.google.de"];
[self testUrl:#"http://google.de"];
}
Output:
INVALID: google
VALID: google.de
VALID: www.google.de
VALID: http://www.google.de
VALID: http://google.de
Lefakir's solution has one issue.
His regex can't match with "http://instagram.com/p/4Mz3dTJ-ra/".
Url component has combined numerical and literal character. His regex fail such urls.
Here is my improvement.
"(http|https)://((\\w)*|([0-9]*)|([-|_])*)+([\\.|/]((\\w)*|([0-9]*)|([-|_])*)+)+(/)?(\\?.*)?"
Below code will let you find the valid URLs
NSPredicate *websitePredicate = [NSPredicate predicateWithFormat:#"SELF MATCHES %#",#"^(((((h|H)(t|T){2}(p|P)s?)|((f|F)(t|T)(p|P)))://(w{3}.)?)|(w{3}.))[A-Za-z0-9]+(.[A-Za-z0-9-:;\?#_]+)+"];
if ([websitePredicate evaluateWithObject:##MY_STRING##])
{
printf"Valid"
}
for such URLS
http://123.com
https://123.com
http://www.123.com
https://www.123.com
ftp://123.com
ftp://www.123.com
www.something.com
The approved answer is incorrect.
I have an URL with an "-" in it, and the validation fails.
Tweeked Vaibhav's answer to support G+ links:
NSString *urlRegEx = #"http(s)?://([\\w-]+\\.)+[\\w-]+(/[\\w-\\+ ./?%&=]*)?";
Some URL's without / at the end are not detected as the correct one in the solutions above. So this might be helpful.
extension String {
func isValidURL() -> Bool{
let length:Int = self.characters.count
var err:NSError?
var dataDetector:NSDataDetector? = NSDataDetector()
do{
dataDetector = try NSDataDetector(types: NSTextCheckingType.Link.rawValue)
}catch{
err = error as NSError
}
if dataDetector != nil{
let range = NSMakeRange(0, length)
let notFoundRange = NSRange(location: NSNotFound, length: 0)
let linkRange = dataDetector?.rangeOfFirstMatchInString(self, options: NSMatchingOptions.init(rawValue: 0), range: range)
if !NSEqualRanges(notFoundRange, linkRange!) && NSEqualRanges(range, linkRange!){
return true
}
}else{
print("Could not create link data detector: \(err?.localizedDescription): \(err?.userInfo)")
}
return false
}
}
URL Validation in Swift
Details
Xcode 8.2.1, Swift 3
Code
enum URLSchemes: String
import Foundation
enum URLSchemes: String {
case http = "http://", https = "https://", ftp = "ftp://", unknown = "unknown://"
static func detectScheme(urlString: String) -> URLSchemes {
if URLSchemes.isSchemeCorrect(urlString: urlString, scheme: .http) {
return .http
}
if URLSchemes.isSchemeCorrect(urlString: urlString, scheme: .https) {
return .https
}
if URLSchemes.isSchemeCorrect(urlString: urlString, scheme: .ftp) {
return .ftp
}
return .unknown
}
static func getAllSchemes(separetedBy separator: String) -> String {
return "\(URLSchemes.http.rawValue)\(separator)\(URLSchemes.https.rawValue)\(separator)\(URLSchemes.ftp.rawValue)"
}
private static func isSchemeCorrect(urlString: String, scheme: URLSchemes) -> Bool {
if urlString.replacingOccurrences(of: scheme.rawValue, with: "") == urlString {
return false
}
return true
}
}
extension String
import Foundation
extension String {
var isUrl: Bool {
// for http://regexr.com checking
// (?:(?:https?|ftp):\/\/)(?:xn--)?(?:\S+(?::\S*)?#)?(?:(?!10(?:\.\d{1,3}){3})(?!127(?:\.\d{1,3}){3})(?!169\.254(?:\.\d{1,3}){2})(?!192\.168(?:\.\d{1,3}){2})(?!172\.(?:1[6-9]|2\d|3[0-1])(?:\.\d{1,3}){2})(?:[1-9]\d?|1\d\d|2[01]\d|22[0-3])(?:\.(?:1?\d{1,2}|2[0-4]\d|25[0-5])){2}(?:\.(?:[1-9]\d?|1\d\d|2[0-4]\d|25[0-4]))|(?:(?:[a-z\u00a1-\uffff0-9]+-?)*[a-z\u00a1-\uffff0-9]+)(?:\.(?:[a-z\u00a1-\uffff0-9]+-?)*[a-z\u00a1-\uffff0-9]+)*(?:\.(?:[#-z\u00a1-\uffff]{2,})))(?::\d{2,5})?(?:\/[^\s]*)?
let schemes = URLSchemes.getAllSchemes(separetedBy: "|").replacingOccurrences(of: "://", with: "")
let regex = "(?:(?:\(schemes)):\\/\\/)(?:xn--)?(?:\\S+(?::\\S*)?#)?(?:(?!10(?:\\.\\d{1,3}){3})(?!127(?:\\.\\d{1,3}){3})(?!169\\.254(?:\\.\\d{1,3}){2})(?!192\\.168(?:\\.\\d{1,3}){2})(?!172\\.(?:1[6-9]|2\\d|3[0-1])(?:\\.\\d{1,3}){2})(?:[1-9]\\d?|1\\d\\d|2[01]\\d|22[0-3])(?:\\.(?:1?\\d{1,2}|2[0-4]\\d|25[0-5])){2}(?:\\.(?:[1-9]\\d?|1\\d\\d|2[0-4]\\d|25[0-4]))|(?:(?:[a-z\\u00a1-\\uffff0-9]+-?)*[a-z\\u00a1-\\uffff0-9]+)(?:\\.(?:[a-z\\u00a1-\\uffff0-9]+-?)*[a-z\\u00a1-\\uffff0-9]+)*(?:\\.(?:[#-z\\u00a1-\\uffff]{2,})))(?::\\d{2,5})?(?:\\/[^\\s]*)?"
let regularExpression = try! NSRegularExpression(pattern: regex, options: [])
let range = NSRange(location: 0, length: self.characters.count)
let matches = regularExpression.matches(in: self, options: [], range: range)
for match in matches {
if range.location == match.range.location && range.length == match.range.length {
return true
}
}
return false
}
var toURL: URL? {
let urlChecker: (String)->(URL?) = { url_string in
if url_string.isUrl, let url = URL(string: url_string) {
return url
}
return nil
}
if !contains(".") {
return nil
}
if let url = urlChecker(self) {
return url
}
let scheme = URLSchemes.detectScheme(urlString: self)
if scheme == .unknown {
let newEncodedString = URLSchemes.http.rawValue + self
if let url = urlChecker(newEncodedString) {
return url
}
}
return nil
}
}
Usage
func tests() {
chekUrl(urlString:"http://example.com")
chekUrl(urlString:"https://example.com")
chekUrl(urlString:"http://example.com/dir/file.php?var=moo")
chekUrl(urlString:"http://xn--h1aehhjhg.xn--d1acj3b")
chekUrl(urlString:"http://www.example.com/wpstyle/?p=364")
chekUrl(urlString:"http://-.~_!$&'()*+,;=:%40:80%2f::::::#example.com")
chekUrl(urlString:"http://example.com")
chekUrl(urlString:"http://xn--d1acpjx3f.xn--p1ai")
chekUrl(urlString:"http://xn--74h.damowmow.com/")
chekUrl(urlString:"ftp://example.com:129/myfiles")
chekUrl(urlString:"ftp://user:pass#site.com:21/file/dir")
chekUrl(urlString:"ftp://ftp.example.com:2828/asdah%20asdah.gif")
chekUrl(urlString:"http://142.42.1.1:8080/")
chekUrl(urlString:"http://142.42.1.1/")
chekUrl(urlString:"http://userid:password#example.com:8080")
chekUrl(urlString:"http://userid#example.com")
chekUrl(urlString:"http://userid#example.com:8080")
chekUrl(urlString:"http://foo.com/blah_(wikipedia)#cite-1")
chekUrl(urlString:"http://foo.com/(something)?after=parens")
print("\n----------------------------------------------\n")
chekUrl(urlString:".")
chekUrl(urlString:" ")
chekUrl(urlString:"")
chekUrl(urlString:"-/:;()₽&#.,?!'{}[];'<>+_)(*#^%$")
chekUrl(urlString:"localhost")
chekUrl(urlString:"yandex.")
chekUrl(urlString:"коряга")
chekUrl(urlString:"http:///a")
chekUrl(urlString:"ftps://foo.bar/")
chekUrl(urlString:"rdar://1234")
chekUrl(urlString:"h://test")
chekUrl(urlString:":// should fail")
chekUrl(urlString:"http://-error-.invalid/")
chekUrl(urlString:"http://.www.example.com/")
}
func chekUrl(urlString: String) {
var result = ""
if urlString.isUrl {
result += "url: "
} else {
result += "not url: "
}
result += "\"\(urlString)\""
print(result)
}
Result
Objective C
- (BOOL)validateUrlString:(NSString*)urlString
{
if (!urlString)
{
return NO;
}
NSDataDetector *linkDetector = [NSDataDetector dataDetectorWithTypes:NSTextCheckingTypeLink error:nil];
NSRange urlStringRange = NSMakeRange(0, [urlString length]);
NSMatchingOptions matchingOptions = 0;
if (1 != [linkDetector numberOfMatchesInString:urlString options:matchingOptions range:urlStringRange])
{
return NO;
}
NSTextCheckingResult *checkingResult = [linkDetector firstMatchInString:urlString options:matchingOptions range:urlStringRange];
return checkingResult.resultType == NSTextCheckingTypeLink && NSEqualRanges(checkingResult.range, urlStringRange);
}
Hope this helps!
did you mean to check if what the user entered is a URL? It can be as simple as a regular expression, for example checking if the string contain www. (this is the way that yahoo messenger checks if the user status is a link or not)
Hope that help
Selfishly, I would suggest using a KSURLFormatter instance to both validate input, and convert it to something NSURL can handle.
I have created inherited class of UITextField which can handle all kind of validation using regex string. In this you just need to give them all the regex string in sequence and their message that you want to show when validation get failed. You can check my blog for more info, it will really help you
http://dhawaldawar.wordpress.com/2014/06/11/uitextfield-validation-ios/
Extending #Anthony's answer to swift, I wrote a category on String which returns an optional NSURL. The return value is nil if the String can not be validated to be a URL.
import Foundation
// A private global detector variable which can be reused.
private let detector = try! NSDataDetector(types: NSTextCheckingType.Link.rawValue)
extension String {
func URL() -> NSURL? {
let textRange = NSMakeRange(0, self.characters.count)
guard let URLResult = detector.firstMatchInString(self, options: [], range: textRange) else {
return nil
}
// This checks that the whole string is the detected URL. In case
// you don't have such a requirement, you can remove this code
// and return the URL from URLResult.
guard NSEqualRanges(URLResult.range, textRange) else {
return nil
}
return NSURL(string: self)
}
}
func checkValidUrl(_ strUrl: String) -> Bool {
let urlRegEx: String = "(http|https)://((\\w)*|([0-9]*)|([-|_])*)+([\\.|/]((\\w)*|([0-9]*)|([-|_])*))+"
let urlTest = NSPredicate(format: "SELF MATCHES %#", urlRegEx)
return urlTest.evaluate(with: strUrl)
}
My solution in Swift 5:
extension String {
func isValidUrl() -> Bool {
do {
let detector = try NSDataDetector(types: NSTextCheckingResult.CheckingType.link.rawValue)
// check if the string has link inside
return detector.numberOfMatches(in: self, options: [], range: .init( location: 0, length: utf16.count)) > 0
} catch {
print("Error during NSDatadetector initialization \(error)" )
}
return false
}
}