Latest 2.0.0
License MIT
Platforms ios 9.0
Frameworks UIKit

Build Status

A simple form validation library written in Swift 4.2.

  1. Features
  2. Demo
  3. Requirements
  4. Installation
  5. Usage


  • Built-in validators

    • Mandatory
    • Maxlength (currently only UITextField are supported) is a special one. Use storyboard to set it up.
    • Minlength
    • Email
    • DigitsOnly
    • EqualTo (an input value equals to another inputs value)
    • AlphaNumeric
    • Regular expressions
  • Custom validators

  • Validates any UITextField or UITextView or you can create your own validatable input fields

  • Add custom styles to highlight invalid input fields

  • Conditional validation


pod try EGFormValidator


  • iOS 8.0+
  • Xcode 8.2+
  • Swift 3.0+


The recommended approach to use EGFormValidator in your project is using the CocoaPods package manager, as it provides flexible dependency management and dead simple installation.


Install CocoaPods if not already available:

$ [sudo] gem install cocoapods
$ pod setup

Go to the directory of your Xcode project, and Create and Edit your Podfile and add EGFormValidator to your corresponding TargetName:

$ cd /path/to/MyProject
$ touch Podfile
$ edit Podfile
source ''
platform :ios, '9.0'

target 'TargetName' do
    pod 'EGFormValidator'

Install into your project:

$ pod install

Open your project in Xcode from the .xcworkspace file (not the usual project file):

$ open MyProject.xcworkspace

You can now import EGFormValidator framework into your files.



1. Extend ValidatorViewController

class MyViewController: ValidatorViewController {

2. Place your validators in viewDidLoad in the order that they has to be executed.

    override func viewDidLoad() {

        // Place your validation code here   
        // Mandatory validation
        self.addValidatorMandatory(toControl: self.fullnameTextfield,
                            errorPlaceholder: self.fullnameErrorLabel,
                                errorMessage: "This field is required")

        // Minlength
        self.addValidatorMinLength(toControl: self.fullnameTextfield,
                            errorPlaceholder: self.fullnameErrorLabel,
                                errorMessage: "Enter at least %d characters",
                                   minLength: 8)

        // Email
        self.addValidatorEmail(toControl: self.emailTextField,
                        errorPlaceholder: self.emailErrorLabel,
                            errorMessage: "Email is invalid")

        // Digits Only
        self.addValidatorDigitsOnly(toControl: self.postalCodeTextfield,
                             errorPlaceholder: self.postalCodeErrorLabel,
                                 errorMessage: "Postal code must contain only digits")

        // Equalty
        self.addValidatorEqualTo(toControl: self.passwordConfirmationTextField,
                          errorPlaceholder: self.passwordConfirmationErrorLabel,
                              errorMessage: "Passwords don't match",
                        compareWithControl: self.passwordTextField)

        // AlphaNumeric
        self.addValidatorAlphaNumeric(toControl: self.alphaNumericTextField,
                               errorPlaceholder: self.aphaNumericErrorLabel,
                                   errorMessage: "Only letters and digits are allowed")

3. Execute self.validate() to validate your form

if self.validate() {
  // form is valid

Add styles: highlight valid and invalid inputs

Just implement setValidation optional method of Validatable protocol . For example:

import UIKit

class SuperTextField: UITextField, Validatable {
   // textfield initializatin 
   override init(frame: CGRect) {
        super.init(frame: frame)    

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)

    func xibSetup() { 
        layer.cornerRadius = 6
        layer.borderWidth = 2


    func setNormalBorderColor() {
        layer.borderColor = UIColor(red: 244.0/255.0, green: 177.0/255.0, blue: 61.0/255.0, alpha: 1.0).cgColor
        textColor = UIColor(red: 86.0/255.0, green: 86.0/255.0, blue: 86.0/255.0, alpha: 1.0)
        backgroundColor = .white

    // MARK: - Validatable protocol implementation 
    func setValidation(state: ValidatableControlState) {
        if state == .error {
            layer.borderColor = UIColor(red: 230.0/255.0, green: 47.0/255.0, blue: 44.0/255.0, alpha: 1.0).cgColor
            textColor = .white
            backgroundColor = UIColor(red: 239.0/255.0, green: 158.0/255.0, blue: 158.0/255.0, alpha: 1.0)
        } else {

Custom validators

Create a validator:

        let myNewShinyValidator = Validator(control: control, // any class that conforms Validatable protocol: use UITextField, UITextView or create your own (for more, see 'Custom input fields' section)
                                          predicate: AlphaNumericValidatorFunction  // a function that complies (Any?, [Any?]) -> Bool
                                predicateParameters: [], // Pass as many extra parametes as you want
                                   errorPlaceholder: errorPlaceholderLabel, // anything that conforms ValidationErrorDisplayable protocol: use UILabel or create your own (for more, see 'Custom error placeholders' section)
                                   errorMessage: "This input is invalid") // Error message

Create a predicate:

       func AlphaNumericValidatorFunction(value: Any?, params: [Any?]) -> Bool {
           let badCharacters = NSCharacterSet.alphanumerics.inverted

           if let myString = value as? String, myString.rangeOfCharacter(from: badCharacters) == nil {
                return true
            return false

Use self.add(validator: myNewShinyValidator) to add your validator.

Custom input fields

Just implement Validatable protocol’s required getValue method. For example:

import UIKit

extension MyDropDown: Validatable {

    // MARK - Validatable Protocol Implementation
    func getValue() -> Any? {
        return self.text // it must return a value that will be validated


Custom error placeholders

Implement ValidationErrorDisplayable protocol’s required setErrorMessage method. For example:

import UIKit

extension SomeCustomView: ValidationErrorDisplayable {

    // MARK - Validation Error Displayable protocol implementation
    func setErrorMessage(errorMessage: String?) {
        // do stuff to show an error message
        self.errorLabel.text = errorMessage


Conditional validation

You can define wheather you want to apply a specific validator or not. Simply add a condition to a validator.

For a custom validator:

self.add(validator: aValidator, condition: { () -> Bool {
   return false // return true if you want to apply this validator and false otherwise

For a core validator:

// in this case it's digit-only validator, the same syntax is applied to the others
self.addValidatorDigitsOnly(toControl: self.myTextfield,
                             errorPlaceholder: self.myTextfieldErrorLabel,
                                 errorMessage: "Digits only please") { () -> Bool {
   return false // return true if you want to apply this validator and false otherwise

Let’s say if you have two fields: a landline and a cellphone. And you want a user to fill in at least one of them.

self.addValidatorMandatory(toControl: self.cellphoneTextfield,
                   errorPlaceholder: self.cellphoneErrorLabel,
                       errorMessage: "Please enter your home phone number or your cellphone") { [unowned self] () -> Bool in
       if let landline = self.landlineTextfield.getValue() as? String, landline.characters.count > 0 {
           return false
       return true

self.addValidatorMandatory(toControl: self.landlineTextfield,
                   errorPlaceholder: self.landlineErrorLabel,
                       errorMessage: "Please enter your home phone number or your cellphone") { [unowned self] () -> Bool in
       if let cellphone = self.cellphoneTextfield.getValue() as? String, cellphone.characters.count > 0 {
           return false

       return true

Latest podspec

    "name": "EGFormValidator",
    "version": "2.0.0",
    "summary": "A simple form validation library written in Swift 4.2.",
    "description": "The EGFormValidator framework allows you to validate any input field in a convenient way and to display error absolutely anywhere you want.nnAvailables built-in form validators:n* Mandatoryn* Digits Onlyn* Minlengthn* Maxlengthn* EqualTon* Emailn* AlphaNumericn* Regular ExpressionnnIt is also extendable, so you can easily create your own input validator.nnAdd custom styles to highlight invalid input fields.nnAdd a condition when a validator should be applied.",
    "homepage": "",
    "license": {
        "type": "MIT",
        "file": "LICENSE"
    "authors": {
        "Evgeny Gushchin": "[email protected]"
    "source": {
        "git": "",
        "tag": "2.0.0"
    "platforms": {
        "ios": "9.0"
    "source_files": "Classes/*",
    "exclude_files": "Classes/*.plist",
    "frameworks": "UIKit"

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