Frederik Winkelsdorf winkelsdorf

FormatStyle in Excruciating Detail

A collection of all of the various options and styles available to you if you'd like to format data into string on iOS 15.

See every option in detail at fuckingformatstyle.com or goshdarnformatstyle.com.

Download the Xcode Playground:

https://github.com/brettohland/FormatStylesDeepDive

Replacing the SceneDelegate When Running Unit Tests

Overview

I've been working through the exercises in the excellent iOS Unit Testing by Example book by Jon Reid, which I highly recommend. However, the book is in beta at the moment and there are some curveballs thrown by iOS 13 that aren't handled in the text yet. Specifically, when I hit the section about using a testing AppDelegate class I thought "This is very good. But what about the SceneDelegate?"

In Chapter 4 the recommendation is to remove the @UIApplicationMain decoration and make a manual top-level call to UIApplicationMain. To wit:

import UIKit

iOS app introspection

Jailbreak in 2024
Create Provisioning Profile in XCode

libdispatch efficiency tips

The libdispatch is one of the most misused API due to the way it was presented to us when it was introduced and for many years after that, and due to the confusing documentation and API. This page is a compilation of important things to know if you're going to use this library. Many references are available at the end of this document pointing to comments from Apple's very own libdispatch maintainer (Pierre Habouzit).

My take-aways are:

You should create very few, long-lived, well-defined queues. These queues should be seen as execution contexts in your program (gui, background work, ...) that benefit from executing in parallel. An important thing to note is that if these queues are all active at once, you will get as many threads running. In most apps, you probably do not need to create more than 3 or 4 queues.
Go serial first, and as you find performance bottle necks, measure why, and if concurrency helps, apply with care, always validating under system pressure. Reuse

Keychain API

kSecAttrAccessible Mapping

Protection Domain (pdmn)	Keychain Accessibility Values
`ck`	`kSecAttrAccessibleAfterFirstUnlock`
`cku`	`kSecAttrAccessibleAfterFirstUnlockThisDeviceOnly`
`dk`	`kSecAttrAccessibleAlways`
`akpu`	`kSecAttrAccessibleWhenPasscodeSetThisDeviceOnly`

	.onDrop(of: [.fileURL], isTargeted: nil) { providers in
	if let loadableProvider = providers.first(where: { $0.canLoadObject(ofClass: URL.self) }) {
	_ = loadableProvider.loadObject(ofClass: URL.self) { fileURL, _ in
	if let fileURL = fileURL, fileURL.pathExtension.lowercased() == "zip" {
	self.logger.info("Dropped \(fileURL.path)")
	DispatchQueue.main.async {
	importer.open(zipArchiveURL: fileURL)
	}
	}
	}

	import SwiftUI

	struct AccessibleView: View {
	@ScaledMetricCustom(relativeTo: .title) var someSize: CGFloat = 100
	@ScaledFont(customFontName: "TimesNewRomanPS-BoldMT", size: 18, relativeTo: .body) var bodyFont

	var body: some View {
	VStack {
	Rectangle()
	.frame(width: someSize, height: someSize)

	//
	// Deduplicated.swift
	// CountriesSwiftUI
	//
	// Created by Alexey Naumov on 17.12.2019.
	// Copyright © 2019 Alexey Naumov. All rights reserved.
	//
	import Foundation
	import Combine

	//
	// BottomSheetView.swift
	//
	// Created by Majid Jabrayilov
	// Copyright © 2019 Majid Jabrayilov. All rights reserved.
	//
	import SwiftUI

	fileprivate enum Constants {
	static let radius: CGFloat = 16

	@propertyWrapper
	struct Expirable<Value: ExpressibleByNilLiteral> {

	let duration: TimeInterval
	private var expirationDate = Date()
	private var innerValue: Value = nil

	private var hasExpired: Bool {
	expirationDate < Date()
	}