A Code Sample to use Core Data Stack as a Singleton

I used to create an instance of my Core Data Stack in AppDelegate file and accessed it from other View Controllers. But I have to modify it because iOS 11 forces to access AppDelegate file in the main thread. So I made my Core Data Stack as a singleton.

If you are looking for a code sample to make your core data stack as a singleton. Please refer the code below.

class func sharedInstance() -> CoreDataStack {
    struct Static {
        static let instance = CoreDataStack()
    }
    return Static.instance
}

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How can I detect iPhone X's screen size?

How can I detect iPhone X’s screen size?

After Apple released iPhone X I am trying to update my application for iPhone X. The UI elements to fit iPhone X I have to detect the screen size of iPhone X and I found the code below which works for me.

if UIDevice().userInterfaceIdiom == .phone {
        switch UIScreen.main.nativeBounds.height {
        case 1136:
            print("iPhone 5 or 5S or 5C")
        case 1334:
            print("iPhone 6/6S/7/8")
        case 2208:
            print("iPhone 6+/6S+/7+/8+")
        case 2436:
            print("iPhone X")
        default:
            print("unknown")
        }
    }

• source

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First impression on iPhone X

Face ID

• Sometimes I feel it’s better than Touch ID. For example, when I see a notification on the Lock screen glancing it is the only thing to read it.
• Sometimes I miss Touch ID. For example when I download and install an app on the App Store I need to double click the upper right button to get it done. In this case Touch ID is better user experience than Face ID.
• A few apps don’t support Face ID yet. So it is not good for iPhone X usage.

iPhone X Plus

I have used iPhone 6 Plus for 3 years and now I changed my main phone to iPhone X. What I feel is a smaller form factor of iPhone X makes me uncomfortable to use when I type. Probably my hands has been accustomed to use a bigger form factor. So I think that iPhone X Plus will be released in the next year.

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How can I fix node-gyp install error?

I have met this error when I try to migrate my service to a different server. At first, I tried to config Python environment with the command below.

sudo apt-get install git python2.7
npm config  set python python2.7

Then I tried to build it again and met another error. So I reinstall build-essential package in my Ubuntu server.

 sudo apt-get install build-essential

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Why should you use AirPod if you are Apple user?

AirPod is the best bluetooth earphone for me. The reason is that AirPod performs switching among Apple devices. I have used many bluetooth earphones which support Multi-Pairing. But most of them didn’t make me satisfied. Apple AirPod helps me my workflow more seamless and now I feel that it’s worth to buy if you are an Apple user.

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If you can't get OAuth Token by SFSafariViewController...?

Suddenly I have experienced this and found that there was a deprecated method. I used to use process URL Scheme with a method below.

func application(_ application: UIApplication, open url: URL, sourceApplication: String?, annotation: Any) -> Bool {
    return true 
}

But now I need to replace the method above to a method below.

func application(_ app: UIApplication, open url: URL, options: [UIApplicationOpenURLOptionsKey : Any] = [:]) -> Bool {
    return true 
}

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Apple Mach-O Linker Error

Your case might be different. In my case I followed them below.

1. Go to your application targets in Xcode
2. Select your app target
3. Select Build Settings
4. Change Build Active Architecture Only to Yes

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iOS numberOfRowInSection isn't called when tableView reloadData is called

When the number of row in TableView is 0 iOS TableView’s reloadData method isn’t called. So I put a code to handle this case.

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Keynote 7.1 , Easy to select an object with Object List

Keynote 7.1 added a new feature which called Object List. With Object List, you can easily select one of the objects in your slide.
Sometimes selecting an object among many objects in your slide is hard. Object List is a solution for that situation.

Choose the View menu on the menu bar and select Show Object List menu under it.

Keynote 7.1 - Object List

As you can see above, the list menu was slid from the left side between the navigator and the main canvas.
Keynote 7.1 is not a major change. But I think that Keynote 7.1 improvement is handy for all users.

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Keynote 7.1 , Easy to replace a font in Keynote

Today Apple released Keynote 7.1. One of the new features is easy to replace a font in your presentation.

If you open your presentation in Keynote 7.1, there is a new font management window.

Font Replacement Window in Keynote 7.1

My first impression is much better intuitive to manage my font. I encourage you to use Keynote 7.1. You can update your Keynote through MacAppstore now.

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P.O.P - Power of Presentation

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