Recent Xcode, iOS and Swift Blog posts

Closures in Swift can be challenging to understand with types like trailing closures, capturing lists, and shorthand syntaxes. They're used ...
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Computed properties are part of a family of property types in Swift. Stored properties are the most common which save ...
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Every year I'm looking back at what I achieved with SwiftLee as well as what I want to achieve in ...
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SwiftUI can work together with UIKit by making it easier to add SwiftUI views to UIKit and visa versa using ...
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Associated types in Swift work closely together with protocols. You can literally see them as an associated type of a ...
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The Result enum is available since Swift 5 and allows us to define a success and failure case. The type ...
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Xcode Mark Lines allows us to create a better overview of sections within our classes or structs. A so-called mark ...
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App Launch Time is the time it takes before your app becomes responsive after startup. As the first experience of ...
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Property Wrappers in Swift allow you to extract common logic in a distinct wrapper object. Since the introduction during WWDC ...
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Build performance can be analysed in Xcode to speed up Xcode builds. This can easily speed up your workflow and ...
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Data validation in apps is important to make sure we save data conforming to the business rules. A name should ...
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Derived attributes are available since iOS 13 and aim to improve fetch performance in many different scenarios. Although we have ...
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Constraints in Core Data are part of an entity configuration. Settings like the entity name and Spotlight display name might ...
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An NSManagedObject lifecycle goes from insertion and updates until deletion in the end. All those events come with their own ...
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Marking pieces of code as available per platform or version is required in the ever changing landscape of app development ...
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Try catch in Swift combined with throwing errors make it possible to nicely handle any failures in your code. A ...
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UserDefaults within apps are used to store data related to user configurations. It's an easily accessible data store for saving ...
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Diffable Data Sources were introduced at WWDC 2019 as a replacement for UICollectionViewDataSource and UITableViewDataSource. The API is available on ...
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Diffable Data Sources were introduced at WWDC 2019 and are available since iOS 13. They're a replacement of the good ...
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WWDC 2017 introduced a new concept available from iOS 11 which is persistent history tracking. It's Apple's answer for merging ...
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SwiftUI is great when it comes down to animations as it does a lot for you with methods like withAnimation ...
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Write-Ahead Logging is the default journaling mode for Core Data SQLite stores since iOS 7 and OS X Mavericks. Journaling ...
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Combining multiple text weights in SwiftUI might not look straight forward at first. If you're used to using UIKit you ...
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The target-action pattern is used in combination with user interface controls as a callback to a user event. Whenever a ...
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Launch screens appear when your app starts up and give the user the impression that your app is fast and ...
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OSLog as a replacement of print and NSLog is the recommended way of logging by Apple. It's a bit harder ...
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ValueTransformers in Core Data are a powerful way of transforming values before they get inserted into the database and before ...
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While developing apps it's important to create focus to get in your flow and speed up development. Full-screen mode can ...
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Xcode 12 introduced support for using Scalable Vector Graphic (SVG) image assets in iOS, macOS, and iPadOS. It's one of ...
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SF Symbols were introduced during WWDC 2019 and are a big present for us developers. Apple basically gave us free ...
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In less than a week we will know what WWDC 2020 has brought to us. Apple has been working hard ...
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While writing methods in Swift you're often running into scenarios in which you sometimes want to ignore the return value ...
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Writing Core Data code with performance in mind helps to prepare your app for the future. Your database might be ...
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It's been a few months since we released the initial version of GitBuddy but it's the right time now to ...
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Expressible literals allow you to initialize types by making use of literals. There are multiple protocols available in the Swift ...
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Swift 5 introduced a decent version of string interpolation with SE-228 and updated the old version of the ExpressibleByStringInterpolation protocol ...
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Custom debug descriptions can help you debug your own custom objects, structs, errors, and other types. Whenever you print out ...
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RocketSim is released and available from the Mac App Store as of today. It all started with building a productivity ...
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URLs are everywhere in an app we built. We reference local files using bundle paths, we fetch data from a ...
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SwiftUI Previews allow us to develop a lot faster as we can now preview our views live in Xcode. Whenever ...
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Custom operators in Swift can make your code easier to read and simpler to maintain. Code can be written less ...
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Custom subscripts in Swift allow you to write shortcuts to elements from collections or sequences and can be defined within ...
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Apple provides us with great classes like the NSFetchedResultsController to interact with Core Data databases in our apps. The API ...
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Testing private methods and variables is often something we run into when writing tests for our applications. You could think ...
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Mocking data requests that are triggered by either Alamofire or URLSession is something we all run into when we start ...
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A command-line tool can be very useful for automating common tasks to boost developer productivity. While developing iOS applications we ...
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With more than 30k stars on Github, you can tell that Alamofire is a popular framework to use for iOS ...
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Testing push notifications in the iOS simulator make it a lot easier to add support for remote notifications. You often ...
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Swift Package Manager is Apple's answer for managing dependencies. We're all familiar with tools like CocoaPods and Carthage but it's ...
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Removing duplicates to get unique values out of an array can be a common task to perform. Languages like Ruby ...
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JSON parsing in Swift is a common thing to do. Almost every app decodes JSON to show data in a ...
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Ranges in Swift allow us to select parts of Strings, collections, and other types. They're the Swift variant of NSRange ...
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Building apps all goes well in the beginning. You're developing an app from scratch, it's stable, and runs perfectly fine ...
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You know it's been a great year if you have the feeling that it went really fast. After looking back ...
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No space left on device is an error message that starts to show up more lately. Over the years, storage ...
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Each app comes with performance issues, crashes, and bugs to fix. Although we try our very best we will always ...
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Asynchronous operations allow you to write long-running tasks in a distinct matter while being able to add dependencies between several ...
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Asynchronous operations allow executing long-running tasks without having to block the calling thread until the execution completes. It's a great ...
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Operations in Swift are a powerful way to separate responsibilities over several classes while keeping track of progress and dependencies ...
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The Thread Sanitizer, also known as TSan, is an LLVM based tool to audit threading issues in your Swift and ...
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Concurrent and Serial queues help us to manage how we execute tasks and help to make our applications run faster, ...
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Dark Mode was introduced in iOS 13 and announced at WWDC 2019. It adds a darker theme to iOS and ...
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Core Data got better and better over the years with improved APIs that make it easier to work with. The ...
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Auto Layout constraints allow us to create views that dynamically adjust to different size classes and positions. The constraints will ...
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Optionals are in the core of Swift and exist since the first version of Swift. An optional value allows us ...
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Xcode 11 was introduced during WWDC 2019 and contained improvements in the way the assistant editor works. If you're using ...
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Xcode breakpoints allow us to debug and find out solutions for nasty bugs. Without breakpoints, it would be a fun ...
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Rich notifications on iOS allow us to make the boring default notification just a little nicer by adding images, GIFs, ...
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When a new iOS version arrives it's oftentimes a moment to reflect on the supported iOS versions and see to ...
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Writing unit tests is just as important as writing your application code. Unit tests are oftentimes the first to be ...
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Swift brings us classes and structs which both can look quite similar. When should you use a struct and when ...
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Xcode Instruments is a developer tool that comes for free with Xcode. It has a lot of useful tools to ...
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Once you get started with Combine you'll quickly run into error handling issues. Each Combine stream receives either a value ...
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An Array and a Set seem to be quite the same in the beginning. They're both collection types and have ...
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A brand new Xcode refactoring engine was introduced in Xcode 9. Although this is quite a few Xcode versions ago ...
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Unused images can exist as a result of iterations in a project. Once a feature is no longer needed and ...
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The UIKeyCommand class allows you to add keyboard shortcuts to your app. Although they might seem useful for iPad only, ...
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Combine debugging can be hard with long stack traces which don't help at all. Asynchronous callbacks follow up on each ...
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A Custom Combine Publisher can add missing functionalities to UIKit elements you use every day. A lot of boilerplate code ...
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Combine is a new framework by Apple introduced at WWDC 2019. The framework provides a declarative Swift API for processing ...
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Xcode Previews have been added in Xcode 11 and allow you to quickly preview the current state of your view ...
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Dynamic member lookup has been introduced in Swift 4.2 with SE-195 and already allowed some pretty nice solutions to for example ...
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An NSBatchDeleteRequest can be used to efficiently delete a batch of entries from a Core Data SQLite persistent store. It runs ...
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Weak self and unowned self in Swift for many of us are hard to understand. Although Automatic Reference Counting (ARC) ...
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Self-documenting code can improve the readability of your codebase. It basically means that you don't have to write comments to ...
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A typealias in Swift is literally an alias for an existing type. Simple, isn't it? They can be useful in ...
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URLSession enables you to download and upload from the background. Although the basics seem to be easy, it's quite hard ...
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Developer productivity is important to deliver your project on time. There's a lot you can do as I already described ...
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@unknown default has been introduced in Swift 5 with SE-0192. It's a new addition to the way we can work ...
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Swift 5.0 has been released in March 2019 and is the first ABI stable Swift release. Although a lot of ...
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WWDC first timer tips help you to get the most out of Apple's World Wide Developer Conference. This conference takes place ...
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How to start your own Swift blog? It's a question I get asked more and more. I've given some tips ...
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Strings files are used for localization in iOS and MacOS apps. These files can grow over time and make it ...
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Fileprivate and private are part of the access control modifiers in Swift. These keywords, together with internal, public, and open, ...
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The required keyword in Swift can be used in front of initializers in Swift. Its usage is simple and it's ...
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Speeding up development to increase productivity can bring you a lot. You'll work more efficient, deliver faster, and you'll feel ...
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Danger plugins can help improve something we do every day: code reviews. Code reviews inside pull requests help you to ...
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Alamofire and URLSession both help you to make network requests in Swift. The URLSession API is part of the foundation framework, whereas ...
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For loop, for each, and repeat are examples of control flow statements in Swift. Although most of them look similar, ...
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Enum usage in Swift: If case, guard case, fallthrough, and the CaseIteratable protocol. These are all terms which could sound familiar ...
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Memory leaks often happen without notice. Although best practices like using a weak reference to self inside closures help a ...
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A QR Code is used a lot to share content or to add a new user in apps like Twitter ...
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A cheat sheet can be a handy tool to quickly reference Xcode, Swift or iOS logic from a compact overview ...
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With 2019 coming closer it's time to review SwiftLee in 2018 and list the top swift development blog posts of ...
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Especially the rulers can help you stop using the Mac screenshot pixel feedback to measure distance in your UI. Simulator ...
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Siri support can be added using an Intent and an IntentUI extension. This adds quite some overhead and is not ...
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Xcode behaviors can change the way how Xcode responds to certain events. Default behaviors help you already by showing for ...
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Although Xcode brings us the Debug View Hierarchy tool , it's often not enough for more advanced UI debugging. Luckily ...
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The new App Store Connect API was announced during WWDC 2018 and makes it possible to write applications for App ...
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Making use of essential shortcuts in Xcode can speed up development and keep you in your flow. Xcode allows you ...
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It's important in any type of programming language to know how to measure the performance of code as there are ...
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Functional programming is often done in Swift and so easy that it could easily hit performance. Iterating over large collections ...
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SwiftLint is a tool by Realm to enforce Swift style and conventions. It's proven to be adopted by a lot ...
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Swift 4.2 is a major release and shipped with Xcode 10. It comes with a lot of code improvements for ...
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Command-click no longer jumps to definition by default since Xcode 9 is introduced. It opens up a handy menu instead ...
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Although the defer keyword was already introduced in Swift 2.0, it's still quite uncommon to use it in projects. Its ...
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CompactMap and flatMap, what are the differences and when do you use each? Swift 4.1 introduced this new method with ...
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Effective development can be achieved by learning more skills, but also by improving the daily routine for you as a ...
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The Swift standard library brings quite some compiler diagnostic directives by default. Although this might not ring a bell at ...
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Where is a powerful keyword within Swift to easily filter out values. It can be used in many different variants ...
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Debugging breakpoints in Xcode allows you to replace prints and reuse debugging statements in future debugging sessions. By simply enabling ...
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The Swift API contains a lot of notifications sent out by the system like NSManagedObjectContextObjectsDidChange in Core Data or the ...
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The Network Link Conditioner on iOS and macOS enables you to test your app in networking conditions like your users ...
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Core Data is Apple’s object graph management and persistency framework for iOS, macOS, watchOS, and tvOS. It's around for a ...
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Xcode custom file templates are a great way to develop just a bit faster and enable you to define a ...
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Xcode is the main IDE for developing software for macOS, iOS, watchOS, and tvOS. It contains a lot of well-known ...
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App Store Optimization can help people discover your app on the App Store for iPhone and iPad. With some useful ...
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During WWDC 2018 Apple announced Xcode 10 with a lot of new features. Many of them are available for you ...
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Almost all apps contain some kind of data requests. Printing data requests could sometimes be handy for debugging purposes. This ...
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Controlling Progress children by default makes it only easy to add children to a Progress instance, but removing is not ...
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UI Tests are a great tool to validate your application. It is easy to create them for your main application, ...
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Using Firebase Crashlytics can help you to solve your crashes faster. In this example we're going to dive into a ...
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Creating an app preview video can be really easy using the simulator in just a few steps. Capturing an iOS ...
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You can symbolicate a crash log with Xcode 9 fairly easy. Even with bitcode, which give you multiple DSYM files ...
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Swift 4.1 is released on the 29th of March and will be shipped with Xcode 9.3. Although it's a minor ...
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Last May the new Buienradar app went live. With over 2 million users each month, it's one of the biggest ...
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In Swift it's kind of unsupported to implemented optional protocol methods. You can, which is ugly, use the @objc syntax: ...
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Swift 3.0 introduced the OptionSet protocol after renaming from OptionSetType. It is a Swift alternative to the well-known and often used ...
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Again, I'm very happy to be one of the few developers to visit WWDC this year. I'm a first timer ...
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Hi there! After thinking a lot of starting my own blog, I've finally made the decision to create one! As ...
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