How do I modify function to be used in MVP architecture? - swift

Question

I have the function below. It works properly.
When a user types any character it validates the user input and hides some imageView based on the input.
#IBAction func onEmailValueChanged(_ sender: UITextField) {
let hasMinimumLength = TextValidationHelper.validateHasMinimumLength(password: sender.text!)
passLengthCheckmarkImageView.isHidden = hasMinimumLength ? false : true
let hasCapitalLetter = TextValidationHelper.validateHasCapitalLetter(password: sender.text!)
passHasUppercaseCheckmarkImageView.isHidden = hasCapitalLetter ? false : true
let hasNumber = TextValidationHelper.validateHasNumber(password: sender.text!)
passHasNumberCheckmarkImageView.isHidden = hasNumber ? false : true
let hasSpecialCharacter = TextValidationHelper.validateHasSpecialCharacter(password: sender.text!)
passHasSymbolCheckmarkImageView.isHidden = hasSpecialCharacter ? false : true
resetButton.isHidden = hasMinimumLength && hasCapitalLetter && hasNumber && hasSpecialCharacter ? false : true
}
But now I want to apply an MVP model on this function to remove the function from the ViewController file.
How can I do that?
Do I need to publish more code to make it possible to create an answer for this question?

Answer 1

It is not a good practice to use any architectural pattern only for method. So assuming you are having a complete app with many classes or files.
An important thing is that it is not fixed/compulsory to use any specific pattern. It actually depends on the code, sometimes you end up writing much code just to handle a method. So try to think the optimal approach to make the code more testable and scalable.
But for your reference, you can check the following code:
On ViewController:
lazy var presenter:Presenter = Presenter(view:self)
#IBAction func onEmailValueChanged(_ sender: UITextField) {
presenter.validateHasMinimumLength(password: sender.text!)
presenter.validateHasCapitalLetter(password: sender.text!)
presenter.validateHasNumber(password: sender.text!)
presenter.validateHasSpecialCharacter(password: sender.text!)
}
//Adopting ViewController:PrensenterViewProtocol on ViewController
extension ViewController:PrensenterViewProtocol {
func updateLengthCheckmarkImageView(isHidden:Bool) {
passLengthCheckmarkImageView.isHidden = isHidden
}
func updateUpperCaseCheckmarkImageView(isHidden:Bool) {
passHasUppercaseCheckmarkImageView.isHidden = isHidden
}
func updateNumberCheckmarkImageView(isHidden:Bool) {
passHasNumberCheckmarkImageView.isHidden = isHidden
}
func updateSymbolCheckmarkImageView(isHidden:Bool) {
passHasSymbolCheckmarkImageView.isHidden = isHidden
}
func updateResetButton(isHidden:Bool) {
resetButton.isHidden = isHidden
}
}
PresenterView protocol as:
protocol PrensenterViewProtocol:NSObjectProtocol {
func updateLengthCheckmarkImageView(isHidden:Bool)
func updateUpperCaseCheckmarkImageView(isHidden:Bool)
func updateNumberCheckmarkImageView(isHidden:Bool)
func updateSymbolCheckmarkImageView(isHidden:Bool)
func updateResetButton(isHidden:Bool)
}
Presenter as:
class Presenter {
weak var view:PrensenterViewProtocol!
private var hasMinimumLength:Bool = false
private var hasCapitalLetter:Bool = false
private var hasNumber:Bool = false
private var hasSpecialCharacter:Bool = false
init(view:PrensenterViewProtocol) {
self.view = view
}
func validateHasMinimumLength(password:String?) {
hasMinimumLength = TextValidationHelper.validateHasMinimumLength(password: password)
self.view.updateLengthCheckmarkImageView(isHidden: hasMinimumLength)
checkAllValidations()
}
func validateHasCapitalLetter(password:String?) {
hasCapitalLetter = TextValidationHelper.validateHasCapitalLetter(password: password)
self.view.updateUpperCaseCheckmarkImageView(isHidden:hasCapitalLetter )
checkAllValidations()
}
func validateHasNumber(password:String?) {
hasNumber = TextValidationHelper.validateHasNumber(password: password)
self.view.updateNumberCheckmarkImageView(isHidden: hasNumber)
checkAllValidations()
}
func validateHasSpecialCharacter(password:String?) {
hasSpecialCharacter = TextValidationHelper.validateHasSpecialCharacter(password: password)
self.view.updateSymbolCheckmarkImageView(isHidden: hasSpecialCharacter)
checkAllValidations()
}
func checkAllValidations() {
let areAllValid:Bool = hasMinimumLength && hasCapitalLetter && hasNumber && hasSpecialCharacter ? false : true
self.view.updateResetButton(isHidden: areAllValid)
}
}