1. Dynamic string with format

this dynamic link use a single input string

extension String {
    
    // MARK: dynamic string in string for single input
    
    func dynamicString(format: String) -> String {
        return String(format: format, self)
    }
}

let format = "Hello %@, Welcome!"
let user = "jack"
print("user.dynamicString(format: format) // Hello jack, Welcome

source: https://stackoverflow.com/a/33441982/8366535

2. How to do two concurrent API calls in swift 4

If you have condition when call API at same time but want to sequentially so you can use 
DispatchGroup()

let group = DispatchGroup()

override func viewDidLoad() {
    super.viewDidload()
    callApiOne()
    callApiTwo()
}


func callApiOne() {
  group.enter()
  //call here
    // in response
    group.leave()

}

func callApiTwo() {
  group.enter()
  //call here
    // in response
    group.leave()
}

source: https://stackoverflow.com/a/50557709/8366535


3. Xcode 12 build failed "non zero arm64"

you can manually add the Excluded Architechure in your Pod project's Build Settings, but it will be overwritten when you use pod install.

In place of this, you can add this snippet in your Podfile. It will write the neccessary Build Settings every time you run pod install

"Error"

ld: in /Users/User/Backup/App/App_ios/ios/Pods/Realm/core/librealmcore-ios.a(bptree.o), building for iOS Simulator, but linking in object file built for iOS, for architecture arm64

clang: error: linker command failed with exit code 1 (use -v to see invocation)

post_install do |installer|
  installer.pods_project.build_configurations.each do |config|
    config.build_settings["EXCLUDED_ARCHS[sdk=iphonesimulator*]"] = "arm64"
  end
end

4. I Got error Jenkins when try to build for production to App Store

This error gets from Jenkins build result.

[12:33:54]: Could not find an edit version on App Store Connect. Try using '--use_live_version true'

[12:33:54]: Couldn't download already existing screenshots from App Store Connect.

this error can be fix in fastlane you can check in github for more solution

https://github.com/fastlane/fastlane/issues/13522

Source: https://stackoverflow.com/a/66278613/8366535

5. Change tabBar title color not real-time change

I try using appearance for change title tabBar color

UITabBarItem.appearance().setTitleTextAttributes([NSAttributedString.Key.foregroundColor: UIColor.white], for: .normal)
UITabBarItem.appearance().setTitleTextAttributes([NSAttributedString.Key.foregroundColor: UIColor.white], for: .selected)

but I got a problem when using  "UITabBarItem.appearance"  is must tap two times for change not realtime
so I've solved this code:

tabBar.tintColor = .green
tabBar.unselectedItemTintColor = .blue

source: https://stackoverflow.com/a/54003278/8366535

6. Add badge to UIView 

Custom uiview adding (badge +  number) into a corner uiview with programatically

Full code custom class uiview

class CustomUIView: UIView {
    
    override func layoutSubviews() {
        super.layoutSubviews()
        
        // MARK: draw circle badge
        let badgeView = UIView(frame: CGRect(x: self.frame.width - 26, y: 6, width: 20, height: 20))
        badgeView.layer.cornerRadius = badgeView.frame.height / 2
        badgeView.layer.borderColor = UIColor.white.cgColor
        badgeView.backgroundColor = .salmon
        badgeView.borderWidth = 2
        badgeView.borderColor = .white
  

        // MARK: add number to circle badge
        let number = UILabel()
        number.textAlignment = .center
        number.center = badgeView.center
        number.frame = badgeView.frame
        number.textColor = .white
        number.font = UIFont.systemFont(ofSize: 12)
        number.text = "4"
        
        // Add the border view to fake the border being there
        self.addSubview(badgeView)
        self.addSubview(number)
        
    }
    
    
}

7. Simple Toast Extension

extension UIViewController {
    func showToast(message : String, font: UIFont) {
        
        let toastLabel = UILabel(frame: CGRect(
                                    x: self.view.frame.size.width/2 - 75,
                                    y: self.view.frame.size.height-100,
                                    width: 200,
                                    height: 35))
        
        toastLabel.backgroundColor = UIColor.black.withAlphaComponent(0.6)
        toastLabel.textColor = UIColor.white
        toastLabel.font = font
        toastLabel.textAlignment = .center;
        toastLabel.text = message
        toastLabel.alpha = 1.0
        toastLabel.layer.cornerRadius = 10;
        toastLabel.clipsToBounds  =  true
        self.view.addSubview(toastLabel)
        UIView.animate(withDuration: 4.0, delay: 0.1, options: .curveEaseOut, animations: {
            toastLabel.alpha = 0.0
        }, completion: {(isCompleted) in
            toastLabel.removeFromSuperview()
        })
    }
}

how use:  self.showToast(message: "Your Toast Message", font: .systemFont(ofSize: 12.0))

source:  https://stackoverflow.com/a/35130932/8366535

8.Try to use "IteratorProtocol"

The makeIterator() function returns an object that inherits the IteratorProtocol protocol. We can use the next() function to get the next value without the need to track the current index. Remember, the next() function returns an optional value.

let names = ["Bob", "Amy", "Mike"]
var nameIterator = names.makeIterator()
print("\(nameIterator.next() ?? "") did the laundry.")
print("\(nameIterator.next() ?? "") did the dishes.")
print("\(nameIterator.next() ?? "") did nothing.")

source: https://medium.com/geekculture/swift-5-use-protocols-to-take-your-code-to-the-next-level-a671972f2f2

9.  Error Jenkins when build for production "Value of type 'UINavigationItem' has no member 'backButtonTitle' "

I don't know why in Jenkins this code get an error, when I running in Xcode that no found error but when build in Jenkins it be error, so for solution, I change back to normal backBarButton empty string

Error in Jenkins 

navigationItem.backButtonTitle = ""

Solution:

navigationItem.backBarButtonItem = UIBarButtonItem(title: "", style: .plain, target: nil, action: nil)