Email Validation is wrong as per Regex - ios

Question

I am using email validation into my project which method is like below
//MARK: isValidEmailID
func isValidEmail(testStr:String) -> Bool {
print("validate emilId: \(testStr)")
let emailRegEx = "^(?:(?:(?:(?: )*(?:(?:(?:\\t| )*\\r\\n)?(?:\\t| )+))+(?: )*)|(?: )+)?(?:(?:(?:[-A-Za-z0-9!#$%&’*+/=?^_'{|}~]+(?:\\.[-A-Za-z0-9!#$%&’*+/=?^_'{|}~]+)*)|(?:\"(?:(?:(?:(?: )*(?:(?:[!#-Z^-~]|\\[|\\])|(?:\\\\(?:\\t|[ -~]))))+(?: )*)|(?: )+)\"))(?:#)(?:(?:(?:[A-Za-z0-9](?:[-A-Za-z0-9]{0,61}[A-Za-z0-9])?)(?:\\.[A-Za-z0-9](?:[-A-Za-z0-9]{0,61}[A-Za-z0-9])?)*)|(?:\\[(?:(?:(?:(?:(?:[0-9]|(?:[1-9][0-9])|(?:1[0-9][0-9])|(?:2[0-4][0-9])|(?:25[0-5]))\\.){3}(?:[0-9]|(?:[1-9][0-9])|(?:1[0-9][0-9])|(?:2[0-4][0-9])|(?:25[0-5]))))|(?:(?:(?: )*[!-Z^-~])*(?: )*)|(?:[Vv][0-9A-Fa-f]+\\.[-A-Za-z0-9._~!$&'()*+,;=:]+))\\])))(?:(?:(?:(?: )*(?:(?:(?:\\t| )*\\r\\n)?(?:\\t| )+))+(?: )*)|(?: )+)?$"
let emailTest = NSPredicate(format:"SELF MATCHES %#", emailRegEx)
let result = emailTest.evaluateWithObject(testStr)
return result
}
OR
func isValidEmailID(email: String) -> Bool {
let regExPattern: String = "[A-Z0-9a-z._%+-]+#[A-Za-z0-9.-]+\\.[A-Za-z]{2,}"
let emailValidator: NSPredicate = NSPredicate(format: "SELF MATCHES %#", regExPattern)
let isValid: Bool = emailValidator.evaluateWithObject(email)
return isValid
}
This both Regex works fine when I enter "modijecky#gmail.com" or any other wrong input but it will not work when I enter "modijecky#gmail.com.com".
So,I find out that "name#.com.com" is a valid email address and there are more sub-domains like this. So now I want user not to enter sub-domains. Is there any REGEX that validate email address within just one domain like "name#gmail.com" not with multiple domains or sub-domains.
I also try different Regex from google and implement it into project but same problem occurs.
Please help me with it.
Thank you

Answer 1

Don’t reinvent the wheel:
Not Reinventing the Wheel: Email Validation in Swift
Basically you can use NSDataDetector to do the heavy lifting and have everything consistent and updated to the way it works in macOS and iOS natively. Not only that but you also avoid regex headaches.
// Simplifying the example from the website a bit
import Foundation
func validate(_ text: String) -> Bool {
let types = NSTextCheckingResult.CheckingType.link.rawValue
guard
let dataDetector = try? NSDataDetector(types: types),
let match = dataDetector
.matches(in: text, options: [], range: NSRangeFromString(text))
.first,
let absoluteString = match.url?.absoluteString
else { return false }
return absoluteString == "mailto:\(text)"
}
validate("test#gmail.com") // -> true
validate(" test#gmail.com") // -> false
This will make sure that the entire text is a single, valid email address without any superfluous characters.

Answer 2

Function Call:
let result = isValidEmail(testStr: "test#test.com.op")
if (result)
{
print ("passed")
}
else{
print ("failed")
}
Function Definition:
func isValidEmail(testStr:String) -> Bool {
// print("validate calendar: \(testStr)")
var returnValue : Bool = false
let emailRegEx = "[A-Z0-9a-z._%+-]+#[A-Za-z0-9.-]+\\.[A-Za-z]{2,}"
let emailTest = NSPredicate(format:"SELF MATCHES %#", emailRegEx)
if (emailTest.evaluate(with: testStr))
{
let fullNameArr = testStr.components(separatedBy: "#")
let IdName = fullNameArr[0]
let domainName = fullNameArr[1]
var number = 0
let string = domainName
for character in domainName.characters {
if character == "."
{
number = number + 1
}
}
if number <= 1
{
returnValue = true
}
}
return returnValue
}
Result:

Answer 3

you should have this code to don't allow subdomain.
func isValidEmail(email:String) -> Bool {
if email.range(of: "#") == nil || email.range(of: ".") == nil{
return false
}
let accountName = email.substring(to: email.range(of: "#")!.lowerBound)
let domainName = email.substring(from: email.range(of: "#")!.upperBound)
let subDomain = domainName.substring(from: email.range(of: ".")!.lowerBound)
//filter for user name
let unWantedInUName = " ~!##$^&*()={}[]|;’:\"<>,?/`";
//filter for domain
let unWantedInDomain = " ~!##$%^&*()={}[]|;’:\"<>,+?/`";
//filter for subdomain
let unWantedInSub = " `~!##$%^&*()={}[]:\";’<>,?/1234567890";
//subdomain should not be less that 2 and not greater 6
if(!(subDomain.characters.count>=2 && subDomain.characters.count<=6)) {
return false;
}
if (accountName == "" || accountName.rangeOfCharacter(from: CharacterSet.init(charactersIn: unWantedInUName)) != nil || domainName == "" || domainName.rangeOfCharacter(from: CharacterSet.init(charactersIn: unWantedInDomain)) != nil || subDomain == "" || subDomain.rangeOfCharacter(from: CharacterSet.init(charactersIn: unWantedInSub)) != nil ) {
return false
}
return true
}