Thomas Hanning

iOS development

UIPopoverPresentationController

Since iOS 9, UIPopoverController is deprecated. Time to look at UIPopoverPresentationController, which has been introduced in iOS 8. Hint: This post has been updated to Swift 3, Xcode 8 and iOS 10 Presenting a Controller as a Popover Presenting a controller as a popover is very straightforward with UIPopoverPresentationController. You

09/15: The Best iOS Development Articles

The best iOS development articles in September 2015. * Using Guard in Unit Tests: The new Swift 2.0 keyword guard has many application cases. This article is about using guard in unit tests. By @ctietze. * Initialization in Swift: An very good overview about initialisation by @sudomakeinstall. * WatchOS 2: Hello, World:

iOS development

Swift Playground: The Monty-Hall-Problem

The Monty-Hall-Problem is a very confusing probability problem. Instead of doing mathematics, we will experiment on a Swift playground. Hint: This post has been updated to Swift 3 The Monty-Hall-Problem The idea is very simple. It is explained in Parade magazine in 1990: Suppose you’re on a game show,

iOS development

NSURL and NSURLComponents

NSURL and NSURLComponents are classes for handling URLs (Uniform Resource Locator). In this post we discuss the most important features of these classes. Initialisation of a NSURL object The initialisation of a NSURL object is very straight forward. The most common way is by specifying a string: let url1 = NSURL(

Swift 2.0: API Availability Checking

Swift is all about safety. With the introduction of the automatic API availability checking in Swift 2.0, there is another great new feature that makes your apps more stable. Every year Apple releases a new major iOS update, and with each update there are new features and APIs. But

tvOS Development

Just a week ago Apple introduced tvOS, which is a completely new platform in the Apple universe. And as an iOS developer, you will love tvOS development. Client-Server Apps It was a little bit irritating at first to hear about the so-called client-server apps based on JavaScript. However, it is

Hard-to-Reproduce Bugs

Sometimes you encounter bugs that are very hard to reproduce. In this post we discuss the two most common reasons for this kind of bug. Multithreading Issues The number one reasons for these bugs are multithreading issues. They seem to be not deterministic, although they are. So one common reason

Should You Use Objective-C or Swift?

At the moment Apple has two major programming languages. So should you use Objective-C or Swift? General Considerations Although Apple says that both programming languages are treated equally, it is very clear that the future belongs to Swift. Just take a look at the talks of the WWDC 2015: There

Swift: Generics

Objective-C lacks one very important feature: Generics. Luckily, Swift has this feature. Generics enable you to declare functions, classes and structs that work with different types. The Problem The most common example for a good generics use case is a stack. A stack is a container that has two operations:

Monthly Review: August 2015

Blog posts about iOS development in August 2015. On The Web: * iOS Live Camera Controlled Particles in Swift & Metal: Very impressive Metal demonstration via @FlexMonkey. * 4 XCODE ASSET CATALOG SECRETS YOU NEED TO KNOW: Nice tricks for working with images via @allonsykraken. * How I Faked My Way into the

Simulator vs Real Device

At development time you can test your application both on the simulator and a real device. But what is the better approach? Hint: This post has been updated to Swift 3, Xcode 8 and iOS 10 The Simulator Out of the box Xcode provides you a lot of simulators (both

Templates in Xcode 6

Xcode provides you a set of project templates. In this post we will discuss theses templates. Master-Detail application This template provides a starting point for a master-detail application. It provides a user interface configured with a navigation controller to display a list of items and also a split view on

The Strategy Pattern

The strategy pattern gives you the possibility to change the concrete implementation of an algorithm any time without breaking the rest of your code. Furthermore, it is a very good example of using polymorphism. Hint: This post has been updated to Swift 3 The Idea Imagine you want to use

Constants In Swift

In Swift there are two types of values: constants and variables. This is very common for a programming language – however, there is one important difference in using constants in Swift. Hint: This post has been updated to Swift 3 Constants vs variables If you want to declare a value, it

Swift: Access Control

Encapsulation is one of the most important object-oriented design principles: It hides the internal states and functionality of objects.  You can achieve this by using the access control features of Swift. Why is access control important? As said before, access control is the most important way to achieve a good

iOS development

Swift: Enums

An enum is a data type that has a finite set of possible values. In this post we discuss will the most important aspects of enums in Swift. Hint: This post has been updated to Swift 3 Declaration The declaration of an enum is very straightforward in Swift. You do

Xcode: Navigating Through Your Project

If you are an iOS developer, you are navigating through your project the whole day. You can save a lot of time and increase your productivity if you know some tricks that make your life easier. Landmarks In Swift landmarks are the successor of Objective-C’s pragma marks. Using them

Building Memory Efficient Apps

The performance of mobile devices got much stronger over the last few years. However, there is and always will be a huge performance deficit compared to desktop computers. At the same time, requirements for the user interface got stronger as well. So there is still the need to write memory

Monthly Review: July 2015

Blog posts about iOS development in July 2015. [thrive_headline_focus title=”On The Web” orientation=”left”] * Strings In Swift 2: Why Strings no longer confirm to the CollectionType. * Xcode Debugging Tip: User Breakpoints: Awesome debugging tip. By @NatashaTheRobot. * Swift’s Type System: Interesting post about Swift’s type system.

The Best iOS Development Resources

There are a lot of very interesting iOS development resources on the internet. This is a list of the best ones. Blogs * Ray Wenderlich: A blog focused on high quality programming tutorials. * NSHipster: A blog founded by Matt Thompson. Weekly posts about Objective-C, Swift and Cocoa. * Ole Begemann: Long existing

Optionals in Swift

Every variable can be declared as a so-called optional in Swift. As an optional, the variable is allowed to become nil what is equivalent to the absence of a value.  Hint: This post has been updated to Swift 3 Optionals If you have a variable that is not an optional,

Objective-C: Nullability

One of the biggest differences between Objective-C and Swift is the handling of nullability. But since Xcode 6.3 there are two new keywords in Objective-C that improve their interoperability: nullable and nunnull. Interoperability problems between Objective-C and Swift If you are interacting with Objective-C API from Swift, you are

Error Handling in Swift 2.0

Swift 2.0 has a new way of error handling. It uses a do-try-catch  syntax,  which is the replacement for NSError .  In this post we will discuss how to use this new syntax. Defining an error Before  an error can be thrown or catched, it must be defined. You can

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Using Custom Fonts

Out of the box iOS provides you a rich set of fonts. But sometimes there is the need to add another font to your project. For example, this could be one of the Google Fonts, which are open source.  In this post we look how you can add a custom

The MVC-Trap

The fundamental software architecture pattern in iOS and Mac OS  development is the Model-View-Controller pattern (MVC). The idea of this pattern is, that each of these three layers has a clear and precise role, which leads to more reusable code and less bugs. However, in iOS development there is a