WWDC2020 is just around the corner*, and it hasn’t been one year since WWDC2019 took place. There is still a lot of ground to cover regarding the new tools and APIs demonstrated then. and In this article we will focus on a feature new to Swift itself: Function Builders.
*: Maybe. :(
If you have been hacking away at SwiftUI, you have probably been wondering how it makes it possible to build great UIs with very nice syntactic sugar. Other than property wrappers, SwiftUI is also possible thanks to Function Builders. In this article, we will briefly mention how SwiftUI uses Function Builders, and later we will create our own function builders that have nothing not do with SwiftUI. This way, it will become evident why Function Builders are really neat, and why they don’t have to be strictly tied to SwiftUI.
As iOS becomes more advanced, features that we thought belonged to the long future start becoming more common place in today’s software. One such feature is speech recognition, which allows a device to take verbal input from a user, transcribe it into text, and do something with it.
In iOS, we can do this using a framework called Speech, and an object called SFSpeechRecognizer. With this class, you can perform all kinds of speech recognition tasks.
Apple’s CryptoKit introduced this year is full of amazing features. Not only does it offer very easy to use cryptography, but it also offers an interface to a security feature that Apple introduced less than a decade ago: The Secure Enclave.
The Secure Enclave is a hardware feature for helping the system work with cryptographically secure data. In this article, we will build upon our previous CryptoKit knowledge (see the article linked above), and we will also learn what the Secure Enclave is all about.
All the way back to 2016, a group of very talented iOS developers released Workflow, a very popular app to let users create actions of different kinds within the system’s constraints. You could create and automate different tasks, such as controlling a server via SSH, downloading all the images from a website, and more… Much, much more.
Apple saw the power of the app and acquired it in March 2017. This was very exciting, but we didn’t hear anything from the app since. Until WWDC 2018. Apple revealed a new app: Shortcuts. This app was built on top of Workflow, and as an Apple app, it allowed it to do many things that Workflow just wasn’t allowed to do, such as toggling system settings, integrating it with other apps (!!), and it was also natively integrated into Siri.
In the article from last week, we explored the basic background execution APIs introduced since iOS 7. We explored how we could request additional time for a task to complete after entering the background, how we could defer downloads with URLSession, and how we could use silent push notifications to trigger background tasks.
The story with background tasks does not end there. iOS 13 introduced more APIs to do better background tasks, and that allow you to do things that weren’t possible before. Apple gave us the new shiny BackgroundTasks framework on WWDC2019. This framework gives developers more flexibility and less constraints to execute code while their apps are in the background. Not only that, but the old Background App Refresh APIs have now been deprecated in favor of a new, modern way to perform them for your app. This changes unifies with the new Background Processing tasks which lets you do more work in the background, while a device is charging, and more.
Formatting Relative Dates With RelativeDateTimeFormatter
A few weeks ago we talked about formatting content with NSFormatter, an abstract class from which multiple formatting classes inherit from to allow you to format different kinds of data in a human-readable form. NSFormatter is not only a class you can inherit from yourself, but as iOS evolves, more formatters will be added to its family. This week, we will explore a new member of this family introduced in iOS 13: RelativeDateTimeFormatter.
Soon after I published this article, Christian Tietze wrote a fair criticism of this idea here.
Once you understand how property wrappers work, you can use this article to apply it to user defaults. The main idea is that property wrappers allow you to store your values differently and even externally. That said, you may or may not want to implement this in a real app. I recommend you read this article first, and then go back to Christian’s to see more downsides of this idea other than the ones I mentioned below.
Swift 5.1 introduced a sleuth of wonderful features, and amongst them, there’s one that is essential for SwiftUI: Property Wrappers. Property wrappers are a powerful feature in Swift that allow you to wrap behavior along with properties. This allows us to do some interesting things. If you have seen SwiftUI, you’ve seen the @State “keyword”, and you know that it allows you to modify structs. This is possible thanks to the behavior “wrapped” within properties marked with it.
iOS has always provided interesting search APIs, but they have always been limited and doing the most interesting tasks required you to either write your own implementation or use private APIs.
iOS 13 has provided some very nice improvements to the UI search APIs. In this article we will talk about two of them.
UISearchBar finally exposes its text field
I have been using UISearchController and UISearchBar for a very long time, and I have always found it bizarre that Apple didn’t expose its underlying text field property. As of iOS 13, the search bar finally exposes it, in the form of a UISearchTextField object.
This article is a continuation to my Common Cryptographic Operations with CryptoKit article. If you want to learn how to use CryptoKit, read that one instead, and come to this one when you need a feature not offered by it.
As I have been playing with the amazing CryptoKit framework in the past few weeks, I have discovered a few more things that CryptoKit currently doesn’t do. This is not generally a bad thing, and I think these limitations are related to what seem to be the goal of the framework:
