A small extension for UISearchBar which shows an UIActivityIndicator while searching

UISearchBar+Ext.swift

//
//  UISearchBar+Ext.swift
//  frazeit
//
//  Created by Maysam Shahsavari on 7/30/18.
//  Edited on 16/05/19 for Swift 5.0.
//  Copyright © 2018 Maysam Shahsavari. All rights reserved.
//

import Foundation
import UIKit

extension UISearchBar {
    private var textField: UITextField? {
        let subViews = self.subviews.flatMap { $0.subviews }
        return (subViews.filter { $0 is UITextField }).first as? UITextField
    }
    
    private var searchIcon: UIImage? {
        let subViews = subviews.flatMap { $0.subviews }
        return  ((subViews.filter { $0 is UIImageView }).first as? UIImageView)?.image
    }
    
    private var activityIndicator: UIActivityIndicatorView? {
        return textField?.leftView?.subviews.compactMap{ $0 as? UIActivityIndicatorView }.first
    }
    
    var isLoading: Bool {
        get {
            
            return activityIndicator != nil
        } set {
            let _searchIcon = searchIcon
            if newValue {
                if activityIndicator == nil {
                    let _activityIndicator = UIActivityIndicatorView(style: .gray)
                    _activityIndicator.startAnimating()
                    _activityIndicator.backgroundColor = UIColor.clear
                    self.setImage(UIImage(), for: .search, state: .normal)
                    textField?.leftView?.addSubview(_activityIndicator)
                    let leftViewSize = textField?.leftView?.frame.size ?? CGSize.zero
                    _activityIndicator.center = CGPoint(x: leftViewSize.width/2, y: leftViewSize.height/2)
                }
            } else {
                self.setImage(_searchIcon, for: .search, state: .normal)
                activityIndicator?.removeFromSuperview()
            }
        }
    }
}

/*
 Usage:
 
 To show the acttivity indicator
 searchController.searchBar.isLoading = true
 
 To stop the activity indicator (assuming it will be called when a network or extensive block is finished)
 DispatchQueue.main.async {
 searchController.searchBar.isLoading = false
 }
 */

Great extension, works like a charm!

Yes great extension, thank you.
Unfortunately it doesn't work on iOS 10, it shows a square. Do you have an idea to fix it ?

Hello,

My suggestion to support iOS 10 :

    var isLoading: Bool {
        get {
            
            return activityIndicator != nil
        } set {
            if newValue {
                if activityIndicator == nil {
                    
                    var style: UIActivityIndicatorView.Style = UIActivityIndicatorView.Style.gray
                    var backgroundColor: UIColor = UIColor.white
                    
                    if #available(iOS 11.0, *) {
                        style = UIActivityIndicatorView.Style.white
                        backgroundColor = UIColor.clear
                    }
                    
                    let _activityIndicator = UIActivityIndicatorView(style: style)
                    _activityIndicator.startAnimating()
                    _activityIndicator.backgroundColor = backgroundColor

                    if #available(iOS 11.0, *) {
                        self.setImage(UIImage(), for: .search, state: .normal)
                    }

                    textField?.leftView?.addSubview(_activityIndicator)
                    let leftViewSize = textField?.leftView?.frame.size ?? CGSize.zero
                    _activityIndicator.center = CGPoint(x: leftViewSize.width/2, y: leftViewSize.height/2)
                }
            } else {
                if #available(iOS 11.0, *) {
                    let _searchIcon = searchIcon
                    self.setImage(_searchIcon, for: .search, state: .normal)
                }
                activityIndicator?.removeFromSuperview()
            }
        }
    }