How to add a bar button to a navigation bar – free Swift 4 example code and tips

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How to add a bar button to a navigation bar – free Swift 4 example code and tips

original source : https://www.hackingwithswift.com/example-code/uikit/how-to-add-a-bar-button-to-a-navigation-bar

Navigation bars are one of the most common user interface components in iOS, so being able to add buttons to them is something you’ll do a lot. You can add buttons to the left and right side of a navigation bar, and as of iOS 5.0 you can add more than one to either side.

Note: bar button items don’t belong to the UINavigationBar directly. Instead, they belong to a UINavigationItem that is currently active on the navigation bar, which in turn is usually owned by the view controller that is currently active on the screen. So, to create bar button items for your view controller, you would do this:

navigationItem.leftBarButtonItem = UIBarButtonItem(barButtonSystemItem: .add, target: self, action: #selector(addTapped))
navigationItem.rightBarButtonItem = UIBarButtonItem(title: "Add", style: .plain, target: self, action: #selector(addTapped))

That will call the addTapped() method on the current view controller when either button is tapped. Note that the first one uses a standard system icon (recommended when it’s available!) and the second one uses text.

Like I said, as of iOS 5.0 you can attach more than one bar button item to either side of the navigation bar, like this:

let add = UIBarButtonItem(barButtonSystemItem: .add, target: self, action: #selector(addTapped))
let play = UIBarButtonItem(title: "Play", style: .plain, target: self, action: #selector(playTapped))

navigationItem.rightBarButtonItems = [add, play]

How to add a bar button to a navigation bar – free Swift 4 example code and tips

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How to add a bar button to a navigation bar – free Swift 4 example code and tips

original source : https://www.hackingwithswift.com/example-code/uikit/how-to-add-a-bar-button-to-a-navigation-bar

Navigation bars are one of the most common user interface components in iOS, so being able to add buttons to them is something you’ll do a lot. You can add buttons to the left and right side of a navigation bar, and as of iOS 5.0 you can add more than one to either side.

Note: bar button items don’t belong to the UINavigationBar directly. Instead, they belong to a UINavigationItem that is currently active on the navigation bar, which in turn is usually owned by the view controller that is currently active on the screen. So, to create bar button items for your view controller, you would do this:

navigationItem.leftBarButtonItem = UIBarButtonItem(barButtonSystemItem: .add, target: self, action: #selector(addTapped))
navigationItem.rightBarButtonItem = UIBarButtonItem(title: "Add", style: .plain, target: self, action: #selector(addTapped))

That will call the addTapped() method on the current view controller when either button is tapped. Note that the first one uses a standard system icon (recommended when it’s available!) and the second one uses text.

Like I said, as of iOS 5.0 you can attach more than one bar button item to either side of the navigation bar, like this:

let add = UIBarButtonItem(barButtonSystemItem: .add, target: self, action: #selector(addTapped))
let play = UIBarButtonItem(title: "Play", style: .plain, target: self, action: #selector(playTapped))

navigationItem.rightBarButtonItems = [add, play]

firebase auth (google,facebook)이용시 사용자 sign out 처리방법

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firebase auth와 facebook, google oauth를 이용 사용자의 접속을 관리하는 경우. 사용자가 sign out작업을 하면 두단계로 이를 처리한다. 우선 firebase auth 단계에서 처리하고 각각 google, facebook에서도 개별 처리해주어야 한다.

https://stackoverflow.com/a/42002262

facebook의 예시

You don’t need completion blocks, as the method is synchronous.

@IBAction func logOut(_ sender: UIButton) {
    guard FIRAuth.auth()?.currentUser != nil else {
        return
    }            

    do {
       try FIRAuth.auth()?.signOut()
       FBSDKAccessToken.setCurrent(nil)
       loggedIn = false
       storedValuesData.setValue(nil, forKey: "savedLoginEmail")
       storedValuesData.setValue(nil, forKey: "savedLoginPassword")
       jumpToVC1()
    } catch let error as NSError {
        print(error.localizedDescription)
    }
}

https://stackoverflow.com/a/40107017

google 의 예시

Try adding GIDSignIn.sharedInstance().signOut() for signout

firebase auth (google,facebook)이용시 사용자 sign out 처리방법

by ⋅ Link

firebase auth와 facebook, google oauth를 이용 사용자의 접속을 관리하는 경우. 사용자가 sign out작업을 하면 두단계로 이를 처리한다. 우선 firebase auth 단계에서 처리하고 각각 google, facebook에서도 개별 처리해주어야 한다.

https://stackoverflow.com/a/42002262

facebook의 예시

You don’t need completion blocks, as the method is synchronous.

@IBAction func logOut(_ sender: UIButton) {
    guard FIRAuth.auth()?.currentUser != nil else {
        return
    }            

    do {
       try FIRAuth.auth()?.signOut()
       FBSDKAccessToken.setCurrent(nil)
       loggedIn = false
       storedValuesData.setValue(nil, forKey: "savedLoginEmail")
       storedValuesData.setValue(nil, forKey: "savedLoginPassword")
       jumpToVC1()
    } catch let error as NSError {
        print(error.localizedDescription)
    }
}

https://stackoverflow.com/a/40107017

google 의 예시

Try adding GIDSignIn.sharedInstance().signOut() for signout

How to set cell spacing and UICollectionView – UICollectionViewFlowLayout size ratio?

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How to set cell spacing and UICollectionView – UICollectionViewFlowLayout size ratio?

original source : https://stackoverflow.com/questions/28325277/how-to-set-cell-spacing-and-uicollectionview-uicollectionviewflowlayout-size-r

#1 answer 

https://stackoverflow.com/a/28327193

property를 조정해서 구현할수도 있고 conform하는 func의 리턴값을 변경해서 구현할수도 있다.

Add these 2 lines

layout.minimumInteritemSpacing = 0
layout.minimumLineSpacing = 0

So you have:

   // Do any additional setup after loading the view, typically from a nib.
        let layout: UICollectionViewFlowLayout = UICollectionViewFlowLayout()
        layout.sectionInset = UIEdgeInsets(top: 20, left: 0, bottom: 10, right: 0)
        layout.itemSize = CGSize(width: screenWidth/3, height: screenWidth/3)
        layout.minimumInteritemSpacing = 0
        layout.minimumLineSpacing = 0
        collectionView!.collectionViewLayout = layout

That will remove all the spaces and give you a grid layout:

If you want the first column to have a width equal to the screen width then add the following function:

func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
    if indexPath.row == 0
    {
        return CGSize(width: screenWidth, height: screenWidth/3)
    }
    return CGSize(width: screenWidth/3, height: screenWidth/3);

}

Grid layout will now look like (I’ve also added a blue background to first cell):

How to set cell spacing and UICollectionView – UICollectionViewFlowLayout size ratio?

by ⋅ Link

How to set cell spacing and UICollectionView – UICollectionViewFlowLayout size ratio?

original source : https://stackoverflow.com/questions/28325277/how-to-set-cell-spacing-and-uicollectionview-uicollectionviewflowlayout-size-r

#1 answer 

https://stackoverflow.com/a/28327193

property를 조정해서 구현할수도 있고 conform하는 func의 리턴값을 변경해서 구현할수도 있다.

Add these 2 lines

layout.minimumInteritemSpacing = 0
layout.minimumLineSpacing = 0

So you have:

   // Do any additional setup after loading the view, typically from a nib.
        let layout: UICollectionViewFlowLayout = UICollectionViewFlowLayout()
        layout.sectionInset = UIEdgeInsets(top: 20, left: 0, bottom: 10, right: 0)
        layout.itemSize = CGSize(width: screenWidth/3, height: screenWidth/3)
        layout.minimumInteritemSpacing = 0
        layout.minimumLineSpacing = 0
        collectionView!.collectionViewLayout = layout

That will remove all the spaces and give you a grid layout:

If you want the first column to have a width equal to the screen width then add the following function:

func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
    if indexPath.row == 0
    {
        return CGSize(width: screenWidth, height: screenWidth/3)
    }
    return CGSize(width: screenWidth/3, height: screenWidth/3);

}

Grid layout will now look like (I’ve also added a blue background to first cell):

Is there a way to get line number and function name in Swift language?

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Is there a way to get line number and function name in Swift language?

original source : https://stackoverflow.com/questions/24103376/is-there-a-way-to-get-line-number-and-function-name-in-swift-language

error message 만들어 출력하는 예

line number, file name, func name을 얻는 방법을 설명

Literal        Type     Value

#file          String   The name of the file in which it appears.
#line          Int      The line number on which it appears.
#column        Int      The column number in which it begins.
#function      String   The name of the declaration in which it appears.

Example

print("Function: (#function), line: (#line)")

With default values in parameters you can also create a function

public func track(_ message: String, file: String = #file, function: String = #function, line: Int = #line ) { 
    print("(message) called from (function) (file):(line)") 
}

which can be used like this

track("enters app")

See documentation for more informationhttps://developer.apple.com/library/content/documentation/Swift/Conceptual/Swift_Programming_Language/Expressions.html#//apple_ref/doc/uid/TP40014097-CH32-ID390