App Development

10 things iOS developers should focus on in 2021

Published on: January 4, 2021

I know. This is a clickbaity title. And yes, I know that this list is not relevant for everybody. I know that not every iOS developer has to learn everything on this list. That said, this list is a list of technologies and skills that I think are either already important, or becoming increasingly important this year. It's a list of technologies and skills that I have learned, plan to learn, or would like to learn this year. It's also a list that hopefully inspires you to broaden your horizons, and learn new things. Or maybe this list inspires you...

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Understanding the importance of abstractions

Published on: July 13, 2020

As developers, we constantly deal with layers of abstractions that make our lives easier. We have abstractions over low level networking operations that allow us to make network calls with URLSession. Core Data provides an abstraction over data persistence that can be used to store information in an sqlite database. And there are many, many more abstractions that we all use every day. Over the past few weeks I have seen many people ask about using Core Data in pure SwiftUI projects created in Xcode 12. These projects no longer require an App- and SceneDelegate, and the checkbox to add...

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How to use SF Symbols in your apps

Published on: April 6, 2020

It’s been a while since Apple announced SF Symbols at WWDC 2019 and I remember how excited everybody was about them. The prospect of having an easy to integrate set of over 1,500 icons that you can display in nine weights sounds very appealing and has helped me prototype my ideas much quicker with good looking icons than ever before. I haven’t heard or seen much content related to SF Symbols since they came out and I realized I hadn’t written about them at all so I figured that I’d give you some insight into SF Symbols and how you...

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Adding your app’s content to Spotlight

Published on: March 23, 2020

On iOS, you can swipe down on the home screen to access the powerful Spotlight search feature. Users can type queries in Spotlight and it will search through several areas of the system for results. You may have noticed that Spotlight includes iMessage conversations, emails, websites, and more. As an app developer, you can add content from your app to the Spotlight search index so your users can find results that exist in your app through Spotlight. An important aspect of the Spotlight index is that you can choose whether you want to index your app contents publicly, or privately....

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Deciding where to store data

Published on: November 25, 2019

Developers often need to store data on behalf of their users. Sometimes it’s a small amount simple data, other times it’s a lot of complex data. Maybe it’s highly sensitive data or maybe it’s less sensitive or even publicly available data. Choosing where to store this data is often not trivial, especially if you might be unaware of the options that are available to you, or the security considerations you need to keep in mind. In this week’s blog post I will show you several storage options that are available to you as an iOS developer, and I'll explain the...

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Adding support for multiple windows to your iPadOS app

Published on: November 4, 2019

Now that Apple has split iPadOS into a separate OS, and launched Catalyst to enable developers to compile their iPad apps for the Mac, there’s a whole new multi-window paradigm we must understand and cater for. Up until this year, we only had to worry about a single window for our iOS applications. This meant that we never had to worry about the user being at two places in our app at the same time. For instance, what would happen if a user has two windows of an app open and both are on the edit profile page? In this...

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Understanding the iOS 13 Scene Delegate

Published on: October 28, 2019

When you create a new project in Xcode 11, you might notice something that you haven’t seen before. Instead of only creating an AppDelegate.swift file, a ViewController.swift, a storyboard and some other files, Xcode now creates a new file for you; the SceneDelegate.swift file. If you’ve never seen this file before, it might be quite confusing to understand what it is, and how you are supposed to use this new scene delegate in your app. By the end of this week's blog post you will know: What the scene delegate is used for. How you can effectively implement your scene...

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Optimizing Your Application’s Reviews

Published on: October 14, 2019

We all love the idea of getting loads of App Reviews, preferably with five stars and a description that explains why our apps are amazing. Unfortunately, users often don’t take the time to reviews the apps they enjoy. Instead, users will review your app when they’re unhappy. If something about your app doesn’t please them or something doesn’t work as expected, they will happily write an angry review and rate your app one star. So how do we get people to review apps when they are happy so they give us five stars? That’s exactly what I would like to...

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High performance shadows for UIView

Published on: July 8, 2015

No app is truly complete without some subtle shadows. Especially now that Google's Material Design is showing us that shadows are cool again we need a way to properly add them in our apps. In my previous post I wrote about a way to create a custom UICollectionView layout. There was one problem with that post though, that shadows are incredibly heavy on the iPhone and scrolling stutters. So can we fix this? The answer is yes and the solution is (surprisingly) easy. A Google search led me to this Stackoverflow question about shadows. The solution I tried first was to simple...

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Creating a custom UICollectionViewLayout in Swift

Published on: July 7, 2015

Note: This blog post has been updated for Xcode 11 and Swift 5 👍🏼 If you’re looking to learn more about the new collection view layout techniques that were introduced in iOS 13, this post should contain everything you need. If you've ever built an iOS app that uses some kind of grid layout or displays a list in a way that doesn't fit a UITableView you have probably used a UICollectionView. This component allows for very simple grid layout creation and it even allows you to dynamically change layouts with beautiful animations. UICollectionView becomes even more powerful and flexible...

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