Check the Valid String for UITextField (non Emoji) in Swift 4.2 .

Kunal Prasad

26 October 2021

Check the Valid String

In Most of App we use the UITextfield for getting the value from user like their name , email or other details , some time user will make the entry of emoji so it is not a valid & we have to face lot of issue to restrict this type of string .

In iOS what we can do , we can select the ASCII Keyboard type but it will work only for English language input but it will not support for other language.

For This what we have to do.

Follow This Steps:

1: First we will take a UITextfield like Firstname

Create a Outlet of this :

@IBOutlet weak var firstNameTextField: UITextField!

2: Take a Submit Button where the user will click & get the Value of Textfield.

Here we will have to check weather the value are empty , valid .

for that write this code.

@IBAction func registerAccount(_ sender: Any) {

if !firstNameTextField.isValid(name:"firstname".localized){
            return
}else{

// here you will get the correct value
}


}

@IBAction func registerAccount(_ sender: Any) {

if !firstNameTextField.isValid(name:"firstname".localized){

return

}else{

// here you will get the correct value

}

3: Now write the Extension.

extension UITextField{


func isValid(name:String)->Bool{
        var errorMessage:String = NetworkManager.sharedInstance.language(key: "pleasefill")+" "
        
        if self.text?.trimmingCharacters(in: .whitespacesAndNewlines) ?? "" == ""{
            errorMessage = errorMessage+name
            NetworkManager.sharedInstance.showErrorSnackBar(msg: errorMessage) // you can use any pop up controller for displaying the warning message
            return false
        }else  if self.text?.containsEmoji == true{
            errorMessage = errorMessage+"valid".localized+" "+name
            NetworkManager.sharedInstance.showErrorSnackBar(msg: errorMessage) // you can use any pop up controller for displaying the warning message
            return false

        }else{
            return true
        }
    }
    
    
    
    func trimmSpace()->String{
        return self.text?.trimmingCharacters(in: .whitespacesAndNewlines) ?? ""
    }


}

extension UITextField{

func isValid(name:String)->Bool{

var errorMessage:String = NetworkManager.sharedInstance.language(key: "pleasefill")+" "

if self.text?.trimmingCharacters(in: .whitespacesAndNewlines) ?? "" == ""{

errorMessage = errorMessage+name

NetworkManager.sharedInstance.showErrorSnackBar(msg: errorMessage) // you can use any pop up controller for displaying the warning message

return false

}else if self.text?.containsEmoji == true{

errorMessage = errorMessage+"valid".localized+" "+name

NetworkManager.sharedInstance.showErrorSnackBar(msg: errorMessage) // you can use any pop up controller for displaying the warning message

return false

}else{

return true

}

func trimmSpace()->String{

return self.text?.trimmingCharacters(in: .whitespacesAndNewlines) ?? ""

}

Note:

1: In first step we are checking the space character .

2: but in second step we are checking weather the string contains emoji or not

4: Now write this Extension for checking the string contains emoji or not .

extension UnicodeScalar {
    
    var isEmoji: Bool {
        
        switch value {
        case 0x1F600...0x1F64F, // Emoticons
        0x1F300...0x1F5FF, // Misc Symbols and Pictographs
        0x1F680...0x1F6FF, // Transport and Map
        0x1F1E6...0x1F1FF, // Regional country flags
        0x2600...0x26FF,   // Misc symbols
        0x2700...0x27BF,   // Dingbats
        0xFE00...0xFE0F,   // Variation Selectors
        0x1F900...0x1F9FF,  // Supplemental Symbols and Pictographs
        127000...127600, // Various asian characters
        65024...65039, // Variation selector
        9100...9300, // Misc items
        8400...8447: // Combining Diacritical Marks for Symbols
            return true
            
        default: return false
        }
    }
    
    var isZeroWidthJoiner: Bool {
        
        return value == 8205
    }
}


extension String {
    
    var glyphCount: Int {
        
        let richText = NSAttributedString(string: self)
        let line = CTLineCreateWithAttributedString(richText)
        return CTLineGetGlyphCount(line)
    }
    
    var isSingleEmoji: Bool {
        
        return glyphCount == 1 && containsEmoji
    }
    
    var containsEmoji: Bool {
        
        return unicodeScalars.contains { $0.isEmoji }
    }
    
    var containsOnlyEmoji: Bool {
        
        return !isEmpty
            && !unicodeScalars.contains(where: {
                !$0.isEmoji
                    && !$0.isZeroWidthJoiner
            })
    }
    
    // The next tricks are mostly to demonstrate how tricky it can be to determine emoji's
    // If anyone has suggestions how to improve this, please let me know
    var emojiString: String {
        
        return emojiScalars.map { String($0) }.reduce("", +)
    }
    
    var emojis: [String] {
        
        var scalars: [[UnicodeScalar]] = []
        var currentScalarSet: [UnicodeScalar] = []
        var previousScalar: UnicodeScalar?
        
        for scalar in emojiScalars {
            
            if let prev = previousScalar, !prev.isZeroWidthJoiner && !scalar.isZeroWidthJoiner {
                
                scalars.append(currentScalarSet)
                currentScalarSet = []
            }
            currentScalarSet.append(scalar)
            
            previousScalar = scalar
        }
        
        scalars.append(currentScalarSet)
        
        return scalars.map { $0.map{ String($0) } .reduce("", +) }
    }
    
    fileprivate var emojiScalars: [UnicodeScalar] {
        
        var chars: [UnicodeScalar] = []
        var previous: UnicodeScalar?
        for cur in unicodeScalars {
            
            if let previous = previous, previous.isZeroWidthJoiner && cur.isEmoji {
                chars.append(previous)
                chars.append(cur)
                
            } else if cur.isEmoji {
                chars.append(cur)
            }
            
            previous = cur
        }
        
        return chars
    }
}

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extension UnicodeScalar {

var isEmoji: Bool {

switch value {

case 0x1F600...0x1F64F, // Emoticons

0x1F300...0x1F5FF, // Misc Symbols and Pictographs

0x1F680...0x1F6FF, // Transport and Map

0x1F1E6...0x1F1FF, // Regional country flags

0x2600...0x26FF, // Misc symbols

0x2700...0x27BF, // Dingbats

0xFE00...0xFE0F, // Variation Selectors

0x1F900...0x1F9FF, // Supplemental Symbols and Pictographs

127000...127600, // Various asian characters

65024...65039, // Variation selector

9100...9300, // Misc items

8400...8447: // Combining Diacritical Marks for Symbols

return true

default: return false

}

var isZeroWidthJoiner: Bool {

return value == 8205

}

extension String {

var glyphCount: Int {

let richText = NSAttributedString(string: self)

let line = CTLineCreateWithAttributedString(richText)

return CTLineGetGlyphCount(line)

}

var isSingleEmoji: Bool {

return glyphCount == 1 && containsEmoji

}

var containsEmoji: Bool {

return unicodeScalars.contains { $0.isEmoji }

}

var containsOnlyEmoji: Bool {

return !isEmpty

&& !unicodeScalars.contains(where: {

!$0.isEmoji

&& !$0.isZeroWidthJoiner

})

}

// The next tricks are mostly to demonstrate how tricky it can be to determine emoji's

// If anyone has suggestions how to improve this, please let me know

var emojiString: String {

return emojiScalars.map { String($0) }.reduce("", +)

}

var emojis: [String] {

var scalars: [[UnicodeScalar]] = []

var currentScalarSet: [UnicodeScalar] = []

var previousScalar: UnicodeScalar?

for scalar in emojiScalars {

if let prev = previousScalar, !prev.isZeroWidthJoiner && !scalar.isZeroWidthJoiner {

scalars.append(currentScalarSet)

currentScalarSet = []

}

currentScalarSet.append(scalar)

previousScalar = scalar

}

scalars.append(currentScalarSet)

return scalars.map { $0.map{ String($0) } .reduce("", +) }

}

fileprivate var emojiScalars: [UnicodeScalar] {

var chars: [UnicodeScalar] = []

var previous: UnicodeScalar?

for cur in unicodeScalars {

if let previous = previous, previous.isZeroWidthJoiner && cur.isEmoji {

chars.append(previous)

chars.append(cur)

} else if cur.isEmoji {

chars.append(cur)

}

previous = cur

}

return chars

}

5: With the help of this Extension you can verified the string contains emoji or valid emoji or only emoji string .