I have 1 UITextfield for password in my iPhone application.
I want to validate this textfield with the following validation.
@#$%^&+=^.*(?=.{10,})(?=.*d)(?=.*[a-z])(?=.*[A-Z])(?=.*[@#$%^&+=]).*$How can I restrict the UITextField with above requirements?
This is how I would do it. The validation should be done at the end when the user has typed in the password and not in between.I will not be using NSRegularExpression.
-(void)textFieldDidEndEditing:(UITextField *)textField{
int numberofCharacters = 0;
BOOL lowerCaseLetter,upperCaseLetter,digit,specialCharacter = 0;
if([textField.text length] >= 10)
{
for (int i = 0; i < [textfield.text length]; i++)
{
unichar c = [textfield.text characterAtIndex:i];
if(!lowerCaseLetter)
{
lowerCaseLetter = [[NSCharacterSet lowercaseLetterCharacterSet] characterIsMember:c];
}
if(!upperCaseLetter)
{
upperCaseLetter = [[NSCharacterSet uppercaseLetterCharacterSet] characterIsMember:c];
}
if(!digit)
{
digit = [[NSCharacterSet decimalDigitCharacterSet] characterIsMember:c];
}
if(!specialCharacter)
{
specialCharacter = [[NSCharacterSet symbolCharacterSet] characterIsMember:c];
}
}
if(specialCharacter && digit && lowerCaseLetter && upperCaseLetter)
{
//do what u want
}
else
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error"
message:@"Please Ensure that you have at least one lower case letter, one upper case letter, one digit and one special character"
delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
[alert show];
}
}
else
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error"
message:@"Please Enter at least 10 password"
delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
[alert show];
}
}
Hope this helps...
You can also do this by using Regex. Here are few example I am providing for you:
// *** Validation for Password ***
// "^(?=.*[A-Za-z])(?=.*\\d)[A-Za-z\\d]{8,}$" --> (Minimum 8 characters at least 1 Alphabet and 1 Number)
// "^(?=.*[A-Za-z])(?=.*\\d)(?=.*[$@$!%*#?&])[A-Za-z\\d$@$!%*#?&]{8,16}$" --> (Minimum 8 and Maximum 16 characters at least 1 Alphabet, 1 Number and 1 Special Character)
// "^(?=.*[a-z])(?=.*[A-Z])(?=.*\\d)[a-zA-Z\\d]{8,}$" --> (Minimum 8 characters at least 1 Uppercase Alphabet, 1 Lowercase Alphabet and 1 Number)
// "^(?=.*[a-z])(?=.*[A-Z])(?=.*\\d)(?=.*[$@$!%*?&])[A-Za-z\\d$@$!%*?&]{8,}" --> (Minimum 8 characters at least 1 Uppercase Alphabet, 1 Lowercase Alphabet, 1 Number and 1 Special Character)
// "^(?=.*[a-z])(?=.*[A-Z])(?=.*\\d)(?=.*[$@$!%*?&])[A-Za-z\\d$@$!%*?&]{8,10}" --> (Minimum 8 and Maximum 10 characters at least 1 Uppercase Alphabet, 1 Lowercase Alphabet, 1 Number and 1 Special Character)
Fourth from the list is your case, following code snippet shows how to use it:
-(BOOL)isValidPassword:(NSString *)passwordString
{
NSString *stricterFilterString = @"^(?=.*[a-z])(?=.*[A-Z])(?=.*\\d)(?=.*[$@$!%*?&])[A-Za-z\\d$@$!%*?&]{10,}";
NSPredicate *passwordTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", stricterFilterString];
return [passwordTest evaluateWithObject:passwordString];
}
Using the method:
if(![self isValidPassword:txtPassword.text]) {
/* Show alert: "Password must be minimum 10 characters,
at least 1 Uppercase Alphabet, 1 Lowercase Alphabet,
1 Number and 1 Special Character" */
}
else {
// Password is valid
}
Condition: Password should contain atleast 8 characters, 1 uppercase and 1 number
Solution in Swift 3
you can write String Extension like this,
extension String {
func isValidPassword() -> Bool {
let regularExpression = "^(?=.*[a-z])(?=.*[A-Z])(?=.*\\d)(?=.*[$@$!%*?&])[A-Za-z\\d$@$!%*?&]{8,}"
let passwordValidation = NSPredicate.init(format: "SELF MATCHES %@", regularExpression)
return passwordValidation.evaluate(with: self)
}
}
//Example 1
var password = "@Abcdef011" //string from UITextField (Password)
password.isValidPassword() // -> true
//Example 2
var password = "Abcdef011" //string from UITextField
password.isValidPassword() // -> false
or you can write function like this,
func validate(password: String) -> Bool
{
let regularExpression = "^(?=.*[a-z])(?=.*[A-Z])(?=.*\\d)(?=.*[$@$!%*?&])[A-Za-z\\d$@$!%*?&]{8,}"
let passwordValidation = NSPredicate.init(format: "SELF MATCHES %@", regularExpression)
return passwordValidation.evaluate(with: password)
}
this will give you the same result.
Swift 3
check if password is strong ?
special characters like !@#$%^&*()_-+ is optional
Why i not use regular expression ?
Because it's difficult to support reserved characters in regular expression syntax.
func isValidated(_ password: String) -> Bool {
var lowerCaseLetter: Bool = false
var upperCaseLetter: Bool = false
var digit: Bool = false
var specialCharacter: Bool = false
if password.characters.count >= 8 {
for char in password.unicodeScalars {
if !lowerCaseLetter {
lowerCaseLetter = CharacterSet.lowercaseLetters.contains(char)
}
if !upperCaseLetter {
upperCaseLetter = CharacterSet.uppercaseLetters.contains(char)
}
if !digit {
digit = CharacterSet.decimalDigits.contains(char)
}
if !specialCharacter {
specialCharacter = CharacterSet.punctuationCharacters.contains(char)
}
}
if specialCharacter || (digit && lowerCaseLetter && upperCaseLetter) {
//do what u want
return true
}
else {
return false
}
}
return false
}
let isVaildPass:Bool = isValidated("Test**00+-")
print(isVaildPass)
You can verify your password validation using the below function just pass a password string and this will return you BOOL value.
-(BOOL) isPasswordValid:(NSString *)pwd {
NSCharacterSet *upperCaseChars = [NSCharacterSet characterSetWithCharactersInString:@"ABCDEFGHIJKLKMNOPQRSTUVWXYZ"];
NSCharacterSet *lowerCaseChars = [NSCharacterSet characterSetWithCharactersInString:@"abcdefghijklmnopqrstuvwxyz"];
//NSCharacterSet *numbers = [NSCharacterSet characterSetWithCharactersInString:@"0123456789"];
if ( [pwd length]<6 || [pwd length]>20 )
return NO; // too long or too short
NSRange rang;
rang = [pwd rangeOfCharacterFromSet:[NSCharacterSet letterCharacterSet]];
if ( !rang.length )
return NO; // no letter
rang = [pwd rangeOfCharacterFromSet:[NSCharacterSet decimalDigitCharacterSet]];
if ( !rang.length )
return NO; // no number;
rang = [pwd rangeOfCharacterFromSet:upperCaseChars];
if ( !rang.length )
return NO; // no uppercase letter;
rang = [pwd rangeOfCharacterFromSet:lowerCaseChars];
if ( !rang.length )
return NO; // no lowerCase Chars;
return YES;
}
for me Best way was to use NSPredicate and regex.
this is regex for your case: ^(?=.{10,})(?=.*[0-9])(?=.*[a-zA-Z])([@#$%^&=a-zA-Z0-9_-]+)$
objective C code:
NSString *regex = @"^(?=.{10,})(?=.*[0-9])(?=.*[a-zA-Z])([@#$%^&=a-zA-Z0-9_-]+)$";
NSPredicate *passwordTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", regex];
BOOL isValid = [passwordTest evaluateWithObject:yourTextfield.text];
use a regex (NSRegularExpression class has docs on how to write the patten itself) and then :
- (BOOL)textField:(UITextField *)theTextField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
//delete
if (string.length == 0) {
return YES;
}
if (self.regEx) {
NSMutableString* check = [NSMutableString stringWithString:theTextField.text];
[check replaceCharactersInRange:range withString:string];
NSTextCheckingResult* match = [self.regEx firstMatchInString:check options:0 range:NSMakeRange(0, [check length])];
if (match.range.length != check.length) {
return NO;
}
}
}
Warning: Restricting the input this way is really confusing for users. You type and type and the character you type just doesnt appear!
I'd maybe go with a small red (!) next to the test field but I'd always allow the input itself!
I have this elegant solution for Forms (like sign-up) where you have a lot of validation
I have in my custom UITextField the outlet:
@IBInspectable var regexpValidation: String? = nil
In storyboard I can access it through attribute inspector and put regexp string like that (for email):
[a-z0-9!#$%&'*+/=?^_{|}~-]+(?:.[a-z0-9!#$%&'*+/=?^_{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?
then in my subclass I have this computed var:
@IBInspectable var regexpValidation: String? = nil // Optional, Set this in InterfaceBuilder
var inputIsValid: Bool {
get {
if let expr = regexpValidation {
return (text.rangeOfString(expr, options: NSStringCompareOptions.RegularExpressionSearch, range: nil, locale: nil) != nil)
} else {
return true
}
}
}
which could be used like this:
override func resignFirstResponder() -> Bool {
if (inputIsValid) {
return super.resignFirstResponder()
}
else {
text = ""
return false
}
}
You need to write your validation code in this delegate method of UITextField
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
Few links that you might want to refer for implementation
Use the control:isValidObject: method of the NSTextFieldDelegate protocol which allows you to validate the value of a NSTextField. Assuming you have all your interface builder bits and pieces configured correctly, you might do something like this:
@interface PreferencesController : NSWindowController <NSTextFieldDelegate> {
IBOutlet NSTextField *username, *password;
}
@end
@implementation PreferencesController
- (BOOL)control:(NSControl *)control isValidObject:(id)object
{
if (control == password) {
// Perform validation and return YES or NO
}
return YES;
}
@end
SWIFT 5 USING RXSWIFT, a better, neat and reactive approach.
validate password function will be like this, Obviously you can add as many conditions as you want as per your requirement.
func validatePassword(password: String) -> (Bool, String) {
//Minimum 8 characters at least 1 Alphabet and 1 Number:
var tuple: (Bool, String) = (true, "")
var string = "Requires atleast"
if(password.rangeOfCharacter(from: CharacterSet.letters) == nil){
string = "uppercase"
tuple = (false, string)
}
if(password.rangeOfCharacter(from: CharacterSet.decimalDigits) == nil){
string += ", number"
tuple = (false, string)
}
if(password.count < 8 ){
string += ", 8 chars"
tuple = (false, string)
}
return tuple }
func isPasswordValid(in string: String) -> Observable<(Bool, String)> {
return Observable.create { observer -> Disposable in
let tuple = self.validation.validatePasswordForSymbol(password: string)
observer.onNext(tuple)
return Disposables.create()
}
}
You can use aforementioned function in viewModel or VC as per your architecture. Then invoke the same function like below in your VC.
passwordTextField.rx.text
.orEmpty //1
.filter { $0.count >= 1 } //2
.flatMap { self.isPasswordValid(in: $0) }
.subscribe(onNext: { result in
print("Valid password", result)
//update UI here
// result will be like (false, "Requires atleast, 8 chars, number")
}).disposed(by: disposeBag)
