Each section below provides a snippet of code that configures a particular DatePicker, followed by the UI component created by iOS and macOS output for the specific component configuration. -- Some SwiftUI styles are not available on both iOS and macOS. For example the Wheel style is iOS only; the Stepper style is …

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In this post, I'll build a simple bar chart in code, and add it to a the default UIViewController created by an Xcode template project. The techniques you'll learn in this article are: Creating a UIView entirely in code Adding Auto Layout constraints to views in the hierarchy using code Calculating view sizes and …

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Constructing Strings String from Literal 1 let str = "Hello, dog!" 2 let str2 = "Hello, 🐶!" Including Escaped Characters 1 print("Backslash: \") 2 print("Tab: \t") 3 print("LF: \nThis is on the next line") 4 print ("CR\r") 5 print("Single Quote: '") 6 …

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This technique is demonstrated within the context of a SwiftUI application, but the real topic of discussion is the NetworkClient singleton used by the SwiftUI app. There's really no difference between how this technique applies for UIKit or AppKit, so it should still be relevant. App Architecture The overall app for …

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Dictionary Fundamentals A Dictionary, provided by Foundation, is a type of hash table that stores key/value pairs. Keys must conform to Hashable Access to elements is O(1) Derived from NSDictionary Best used for key/value storage where lookup by key is the primary use case. However, Apple has added a lot of handy …

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This post covers how to use the Grand Central Dispatch's DispatchGroup object to coordinate separate web requests so that UI updates can be completed at the same time, even when asynchronous requests aren't guaranteed to return in a predictable order. This post is primarily a tutorial of using GCD's DispatchGroup, and …

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This post is a cheat sheet for sorting sequences of custom objects using Swift's sort operators. While sorting simple types (String, Int) are covered well in Apple's documentation on the subject and in many other places, I've focused below on sorting custom object types, which is more relevant to my daily work. The …

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What is Map? Map is a term that has roots in other technologies (such as Hadoop big data processing, which is where I've used it before 🙂). Map means to iterate over a sequence of objects, and perform some operation on each one, returning a new sequence of objects as the final output. The operation performed is …

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What is Reduce? Map is a general term that has roots in other technologies (such as Hadoop big data processing, which is where I've used it before 🙂). Reduce means to iterate over a sequence of objects, and perform some operation on each one, returning some summary value computed from the entire set. Map and Reduce are …

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This technique demonstrates the simple but useful task of capturing the contents of a UIView as a JPEG image data object. The resulting Data object can be written to a .jpg file, uploaded to a web service, or sent as an e-mail attachment (as is covered in this related post). Application This technique is relatively …

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