Sometimes you may find it useful to transfer an existing app you deployed on a particular simulator, to another simulator without having to build and run the app again in Xcode. The main scenario I have in mind is during beta time, when you want to check how an existing app, built with the current
I’m happy to share the news that this year at WWDC Apple finally gave us the navigation API for SwiftUI we’ve been waiting for since the framework was introduced in 2019. If you follow me you may know I like programmatic navigation and I was never a fan of the API the team released with
Swift 5.6 introduced a few addition to the language, and in particular one will be quite important in the future and is the keyword any to mark existential types. At the time of writing, this keyword is optional, but in future Swift versions some code will need to be refactored to avoid warnings and, eventually,
We all love SwiftUI for its declarative approach and the ability to quickly prototype a UI. Its simplicity has a few drawbacks though, for example we don’t have full access to the actual view in the hierarchy. One of the problems is taking a screenshot of a particular View. If we deal with UIKit, getting
Sometimes you may need to display HTML content in your app, even if you don’t use a framework to make hybrid apps. Usually you can just open the mobile version of your website to show a particular page, but what if your app need to work offline? Turns out it is still a requirement, even
One of the advantages of the introduction of async await in Swift 5.5 is the ability to test asynchronous code in a clear and concise way, and even if we’re not ready to introduce async await in our code base, we can at least start adopting it in our tests.Before you start reading I leave
One of the new features of async await I was really excited about is AsyncSequence, which provides a new way to receive data asynchronously in loops. It can be seen as an alternative to Combine, and I think both of them have reason to exist.Before you continue reading, I suggest to get familiar with async
When I found out about the addition of async await in Swift at 2021 WWDC I was eager to try it out, but the fact that is was iOS 15 only was a bummer, since some of my apps still support back to iOS 10. The good news is that the amazing team behind Swift
A nice addition to SwiftUI at WWDC21 is the new refreshable modifier to refresh view contents. This new feature is powered by maybe the biggest announcement at WWDC21: the new async/await pattern introduced in Swift 5.5.While this isn’t an article about this specific topic is important to know that what we’re going to see here
My third article about the new features added to SwiftUI at WWDC21 is a mix between two of them I’ve already covered in my previous posts. This time my goal is to draw an analog clock with the new Canvas view. Since I’m building a clock I’ll need a way to refresh my SwiftUI view
This article is about another nice introduction in SwiftUI at WWDC21, the Canvas view. Canvas is also the name Apple gave to the live preview of SwiftUI views in Xcode, so you may find this post by accident while looking for that specific feature. In a sentence, the new Canvas view is a particular view
At WWDC21 Apple introduced TimelineView, a new SwiftUI View that update itself according to a schedule instead of relying on state variables. It may be useful in some scenario, for example if you want to refresh a view only every X seconds, or if you want to animate something providing new frames at a given
This post is about a couple of project I put on GitHub to implement authentication via biometric (FaceID or TouchID on the iPhone) and to save login information on the KeyChain. I wanted to have some fun with SwiftUI so I implemented a custom keypad to enter a PIN, with a button to invoke biometric
In this article I’ll show you how to integrate ARKit in a SwiftUI app. With this simple app, you’ll be able to tap on two points of the AR scene and calculate the distance between them. As usual, the code is available on GitHub. ARKit view Let’s start with ARKit. The example is quite simple,
UPDATE: WWDC21 introduced refreshable, a view modifier to implement pull to refresh in a List, see the example at the end. This article is still valid if you want to target iOS 13 and 14 as the new modifier is only iOS 15 compatible. Pull down to refresh a list is something quite common for
I’ve written about CoreML and Vision in the past and this time I decided to use both of them to perform object recognition in images in a simple iOS app. You can find the post about Vision at this link, in the example I used Vision to perform barcode detection and OCR. My first post
This article is about an app I decided to make in order to play with CoreML and SwiftUI. I wanted to make a reader for RSS feeds, and I though it would be a good idea to include a model to automatically label the entries of the feed. The app, and the playground I used
I really like SwiftUI but there is something that I’m not fond of, the fact that in order to push a new view into the stack you need to create it inside NavigationLink. Imagine you have view A and after pressing a button you can either go to view B or C. You can have
Today I felt like experimenting with ARKit and I couldn’t figure out a sample project to start with. When I want to start exploring a new framework or a new API, my approach is usually to start with something simple, but starting with an actual use case.So I though, what about a video player that
This post is about my first macOS app built with SwiftUI. I needed a utility to browse local images instead of using the Finder, I’m sure there are plenty of great alternatives out there but I thought I’d better make one to finally write a macOS app with SwiftUI. Last time I needed to make
If you follow me you know I like sharing code on GitHub and distribute small utilities via Swift Package Manager (by the way this is my article about SPM).Sometimes though, we cannot share our source code and need our customers to integrate our package. We can’t share the code via SPM, so we need to
As an iOS developer I sometimes ask for a 1024×1024 PNG image to use as app icon, and as you probably know this image has to be resized to a few different formats in order to be used in the app.There are great tools out there, some of them available in the Mac App Store,
In this post I’m going to show you how I implemented OCR, both on an image or live from the camera feed, by using Vision, and I’ll use the same view controller to perform live scan of barcodes. I already wrote about barcodes in the past so I won’t go into details about that part
Inspired by an episode of ATP and by this blog post by Alex Chan I decided to write a simple app to find out which lenses I use the most on my iPhone.The post linked above teach you how to use exiftool, and if you have your photo library on the Mac this is a great option.But what if
Nowadays, we take for granted that our phones are always connected to the internet, it may be WiFi, 4G or even 5G if you have an iPhone 12 🙂Being offline is not something that happens too frequently, but it is a possibility. While we can always show an error message, it can be nice to
This article is about one of the new features of iOS 14: Widgets. I’ll show you how to write a simple widget in SwiftUI, and how to update the widget data from your iOS app.As usual, all the code is available on GitHub. Intro What is a Widget? Is an extension to your app, showing
This article is about one of welcome additions to SwiftUI in 2020: LazyVGrid and LazyHGrid. As the name suggest, you can compose vertical and horizontal grid layout in a lazy way with those views. If you’re interested in lazy layout, check out my previous article on the topic. The sample project In this article I’ll
SwiftUI introduced from the very beginning the components HStack and VStack to group views in an horizontal or vertical stack. Those components load all their children up front, so they’re not suitable for implementing a long list of items, as you’d rather have lazy loading.One alternative was using the List component, which implements lazy loading,
This article is about some news in SwiftUI app cycle. With the second release of SwiftUI, is finally possible to make an app entirely in SwiftUI, without having to embed it in UIKit or AppKit on the Mac. We’ll see how to create a SwiftUI only app, manage independent Scenes and share data between them.As
This post is about enhancements in Function Builders in Swift 5.3. I wrote two articles about Function Builders in the past so you may want to check them out before continuing with this one. Introduction to Function BuildersCreate a DSL with Function Builders UPDATE: the feature finally made it to the language and is now
As you know if you follow me I have many hybrid apps, with native code and web content. Recently I encountered a problem: I needed to show a web page and download a file from it. As most developer do these days, I looked for this very post title on Google, and I couldn’t find
I like the fact that Apple takes accessibility quite seriously. We have talks during WWDC, and tools like the Accessibility Inspector to help us test and audit our apps.In this article I’ll show you how to write your CSS in order to support dynamic fonts in iOS, so when your user changes the preferred font
Using lists is very common in an iOS app. UITableViews are great and have been there from the very beginning, so you can find tons of articles about infinite scrolling. But what about SwiftUI?You don’t have UITableView, but you can use List. Although you can achieve a similar result you don’t have the concept of
I’ve written another article about Function builders so you may want to have a quick read to that as well. The example I used in the article is really simple, but I go into more details about Function Builders. UPDATE: the feature finally made it to the language and is now called Result Builders. You
SwiftUI has radically changed the way we build our UI, introducing a declarative syntax. Swift itself had to change in order to support some of the features of SwiftUI and this article is about one of them: function builders. As a reference, this is the pitch on swift.org for the feature. The idea is to
Swift Package Manager is a tool for helping distributing Swift code and has been around since Swift 3, but with Xcode 11 Apple finally integrated it into the IDE we all use to make iOS apps so it is easier than ever to adopt SPM.In this article I’ll talk about how to integrate packages distributed
One of the new features of Xcode 11 is the ability to see a live preview of a SwiftUI view in what is called the Canvas. This is really convenient while working with a UI as you can modify the code and have an immediate feedback about the result.Wouldn’t it be cool to have a
One of the things I like about iOS development is that the latest version of the operating system has usually a very good adoption rate, but iOS 13 doesn’t support a pretty popular model like iPhone 6 and sometimes your customers need to use older devices, I still have to support iOS 9 so devices
Sometimes you need to share code between iOS and Android, or you have business logic for a customer already written in JavaScript because it is used on the web.If you need to run JavaScript code on your app loading a page into a WkWebView is one of your options and you can read my previous
As you probably know UIWebView has been deprecated in iOS 13, I’ve use it in my projects for years and it was really convenient to display HTML pages inside an app but even to interact with Javascript, for example to perform operations on JSON files sharing the same login with Android and even with the
Back in July I wrote a post about Navigation in SwiftUI trying to explain the difference between NavigationLink and DynamicNavigationDestinationLink. The latter has been deprecated, so the article is now useless, you can still find it here https://www.gfrigerio.com/navigation-in-swiftui-deprecated/I updated the repository on GitHub to remove the deprecated code and provide a few examples of various
Almost every iOS app needs to display images, you can have them in your app’s bundle or you load them from an external URL, and that’s what this article is all about.As usual you can find the source code on GitHub at this link Building the UI In the example I’m presenting a list of
WWDC 2019 was really packed with new stuff for iOS and the new data sources for TableViews and CollectionViews didn’t get the same attention as SwiftUI but are a really nice addition for people still working with UIKit. I’m going to focus my post on UITableViewDiffableDataSource but there is a similar API for CollectionViews and
If you are a registered developer Apple sent you an email reminding you to update your app to implement Dark Mode. There is a WWDC session dedicated to that, this post is a quick introduction to the topic with an example on how to implement a theme manager in your app. I think it is
One of the topics I wanted to explore about SwiftUI was how to integrate CoreData in it, and I want to describe two approaches you can follow: a direct one using property wrappers and another one by having a class hide the existence of Core Data to the user.I usually prefer the latter, as it
If you came across this blog post and you’re happy because you didn’t think it was possible to use NSAttributedString in SwiftUI I have a bad news: it isn’t supported yet. Text in SwiftUI accept a String and there isn’t the equivalent of attributedText you can find in UILabel. So what is this article about?
Progress bars and activity indicators is something we tend to use a lot in iOS applications and it is nice to customise them instead of using all the time the standard UIActivityIndicatorView.I think SwiftUI makes it really easy to build this kind of views and I implemented 4 of them in my sample GitHub project
UPDATE: DynamicNavigationDestinationLink has been deprecated so most of this article is useless. I wrote a new one and updated the GitHub repository In this post I want to explain the difference between NavigationLink and DynamicNavigationDestinationLink in SwiftUI with a quick example and point out the differences between them.You can find the sample code on GitHub
SwiftUI was one of my favourite announcements during WWDC 2019 alongside Combine. At the time I’m writing this post, mid July, beta 4 has just been released and although it isn’t yet stable I think SwiftUI is starting to get interesting. I think it will be hard to drop iOS 12 support soon, but SwiftUI
This year’s WWDC was packed with new stuff for Swift developers, and one of them is property wrappers, formerly known as property delegate. Actually we knew about property delegate before WWDC, as there was a proposal in Swift.org a few months ago (you can read it at this link) but we didn’t know about SwiftUI
This is the second post about Combine, after my quick introduction you can find here https://www.gfrigerio.com/combine-first-example/I’m using the same GitHub project https://github.com/gualtierofrigerio/CombineTest but this time I’m focusing on networking, with a similar example to the one I used for my series of posts about Future&Promise, RxSwift and AlamoFire. I’ll build the same table view controller
This is the first of a series of posts about the new stuff announced at WWDC 2019. First of all let me tell you that it was one of the best WWDC in years, maybe even better than 2014 with the introduction of Swift. A new declarative UI framework was on my wish list, and
As I was playing with my GitHub project about networking I thought it would be interesting to try some different ways to implement the RESTClient protocol. In this article I’m going to show how I used Alamofire and then Moya (which itself uses Alamofire) instead of my custom network layer based on URLSession. I’m going
I wrote this article as I was (finally!) able to play with RxSwift. I’m glad I found the time to get to know the framework, as it is getting more and more popular and the best way to learn is to open Xcode, try it out and write an article about it. I have to
Most of the apps we write rely on some sort of data fetching from the network. It can be our backend, or some public API, but we need to get data and we can only to is asynchronously. This is true for networking, but it isn’t the only case. In this article I’ll stick with
Showing PDFs is pretty common for an iOS app. It could be a privacy policy document, an invoice, a flyer the company distributes on paper and via its app, a magazine.There are three possible ways of displaying a PDF. The simplest is to use a Webview. Just like loading a local page, or a remote
After a few projects made for fun, and for learning, I decided to publish something useful as a CocoaPod: a barcode and QR code scanner. I worked on a similar feature for an app available in the App Store in Objective-C, and decided to rewrite it in Swift to make it available on GitHub. https://github.com/gualtierofrigerio/GFBarcodeScanner
I don’t think I need to write about the importance of testing. We all know it is critical to add some testing to the code, so we refactor code, add new functionalities, fix bugs and check that the existing stuff didn’t break. Maybe writing tests isn’t the most exciting part of the job, but it
In one project I was working on recently I needed to mimic the behaviour of css background cover in a canvas and I think it could be useful to share my implementation. While I think it is always a good idea to use CSS when possible I found myself in a situation where I wasn’t
In this article I’m describing the GitHub project FitnessExample you can find here: https://github.com/gualtierofrigerio/FitnessExampleThe main topic is communicating between iOS and watchOS, but I thought I could introduced some HealthKit stuff as well as fitness is a very popular category of watchOS apps. I’ll update the article as I add functionalities to the project, the
I’ve just committed a project on GitHub for an app I’d like to make for myself. The idea is to show a hierarchy of images, organised in folders, via a table view for a quick preview and then in a scroll view once I select a particular folder. https://github.com/gualtierofrigerio/FolderImageViewer The idea is to show pictures
I recently put a sample project on github for using Apple Maps on an iOS application as I wanted to play with Core Location and Maps since I only dealt with Google Maps via Javascript in my existing apps. Here is the link to the project: https://github.com/gualtierofrigerio/GFMapKitWrapper I’ll eventually make it available on CocoaPods so
I want to share my experience building and distributing apps with xcodebuild hoping to help some iOS developer struggling with automating build and distribution via command line. There are two ways to distribute a test version of your app for iOS: TestFlight and Ad Hoc.The former allows you to submit a build to App Store
I bought BeatsX right after they were available and this fall I found a good deal and finally got a pair of AirPods. Now that I have both I can write a quick article about the pros and cons, I sometimes find twitter threads about which one to buy and 280 chars aren’t enough, so
Here’s a quick guide to implement Push notifications on iOS. Every now and then I need to implement push notification and I always forget how to create the certificate and convert it to use with python, so this guide will be helpful to the future myself and hopefully to some fellow developers 😉Actually, creating the