If you are working on a project then this is very common to add a toolbar above the keyboard. In this tutorial, we will learn how to add a toolbar above the keyboard using UITextField Extension by writing just one line of code. Using UITextField Extension will make our code reusable and cleaner.
Create a Swift file and name it UITextField+Additions (you can choose other name as well).

Now in this file create an Extension of UITextField and import UIKit framework. Add below code in the swift file we have just created.

import UIKit
extension UITextField {
    
    func addInputAccessoryView(title: String, target: Any, selector: Selector) {
        
        let toolBar = UIToolbar(frame: CGRect(x: 0.0,
                                              y: 0.0,
                                              width: UIScreen.main.bounds.size.width,
                                              height: 44.0))//1
        let flexible = UIBarButtonItem(barButtonSystemItem: .flexibleSpace, target: nil, action: nil)//2
        let barButton = UIBarButtonItem(title: title, style: .plain, target: target, action: selector)//3
        toolBar.setItems([flexible, barButton], animated: false)//4
        self.inputAccessoryView = toolBar//5
    }
}

1. Create a UIToolbar
2. Create a UIBarButtonItem of flexibleSpace type, it will fill the space and help to push our button to right or left depend on sequnce.
3. Create a UIBarButtonItem with title, target and selector from the parameters
4. Set toolbar items
5. Assign this tollbar as inputAccessoryView to the UITextField
Now move to your UIViewController class and in viewDidLoad function call above function with your UITextField object, you also need to create a function tapDone which we will pass as selector parameter.

@IBOutlet weak var myTextField: UITextField!
override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
    self.myTextField.addInputAccessoryView(title: "Done", target: self, selector: #selector(tapDone))
    
}
@objc func tapDone() {
    self.view.endEditing(true)
}

Now run the code

Padding in UITextField

Now let’s add two more functions in the above UITextField Extension

func setLeftPadding(padding: CGFloat) {
    let paddingView = UIView(frame: CGRect(x: 0, y: 0, width: padding, height: self.frame.size.height))
    self.leftView = paddingView
    self.leftViewMode = .always
}
func setRightPadding(padding: CGFloat) {
    let paddingView = UIView(frame: CGRect(x: 0, y: 0, width: padding, height: self.frame.size.height))
    self.rightView = paddingView
    self.rightViewMode = .always
}

In the above function, we are creating a UIView of the desired width and assigning it to UITextField leftView or rightView.
Now inside your UIViewController class in viewDidLoad function write one more line.

self.myTextField.setLeftPadding(padding: 20)

Run the code again

The final UITextField Extension file will be below

import UIKit

extension UITextField {
    
    func addInputAccessoryView(title: String, target: Any, selector: Selector) {
        
        let toolBar = UIToolbar(frame: CGRect(x: 0.0,
                                              y: 0.0,
                                              width: UIScreen.main.bounds.size.width,
                                              height: 44.0))//1
        let flexible = UIBarButtonItem(barButtonSystemItem: .flexibleSpace, target: nil, action: nil)//2
        let barButton = UIBarButtonItem(title: title, style: .plain, target: target, action: selector)//3
        toolBar.setItems([flexible, barButton], animated: false)//4
        self.inputAccessoryView = toolBar//5
    }

    
    
    func setLeftPadding(padding: CGFloat) {
        let paddingView = UIView(frame: CGRect(x: 0, y: 0, width: padding, height: self.frame.size.height))
        self.leftView = paddingView
        self.leftViewMode = .always
    }
    
    func setRightPadding(padding: CGFloat) {
        let paddingView = UIView(frame: CGRect(x: 0, y: 0, width: padding, height: self.frame.size.height))
        self.rightView = paddingView
        self.rightViewMode = .always
    }
}

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