Designing an application’s UI can be difficult without actual data to present. Early on in the design process, data sourced from something like an array can suffice. Later on, however, our data sources become more dependent on actual data stores, such as what Core Data provides us. During developmen...

Updated on July 27, 2016 – Additional Cheats Having trouble recalling how to perform basic Core Data operations? This cheat sheet is a handy reference to keep you productive with Core Data and Swift! The code snippets below are here to help jog your memory when it’s been a while since you’ve worked ...

The need to collect data via text input is a common in many applications. This walk-through showcases how to create a custom UITableViewCell for accepting text input within a UITableView. Table Views for Data Entry? Table views provide nice, built-in styles that present a form-like view for collecti...

In Fundamentals of NSNotificationCenter in Swift, a commenter asked me to elaborate on a response I’d given to a dialog going on below the blog post. I had stated: If you need a more structured environment around your [instance]-to-[instance] communication, delegates … are probably a better choice [...

The question of how to convert #define macros from Objective-C to Swift is explained fairly simply in the [Apple developer documentation on the subject][1]. For simple macros, it’s a matter of rewriting them as global constants. In fact, if you’re using the hybrid Objective-C — Swift approach to wri...

A few weeks ago I wrote about Immutable Types and Changing State in Swift, where I hoped to convey an “aha!-moment” that happened for me. Since then, I’ve learned a bit more. For example, the technique I presented for transforming instances of a Type immutably actually come for free when you use a v...

Installing MAMP was easy. I did, however, spend at least 45 minutes trying to get MySQL Workbench to connect to my local MySQL database server. The solution was simple, but getting there led me around the Internet and back with little help. Hopefully this signpost will help others having connection ...

Updated on November 19, 2015 – Swift 2.0 As I approached testing my Core Data model, I have to admit I was apprehensive. How in the world was I going to write unit tests for my model layer that depended on a database. Past experience with trying to write tests with databases was painful. I feared th...

Dabble in Swift for long and the functional programming paradigm will most certainly appear on your radar. From conferences to books to blog posts, I’ve seen a lot in the functional programming arena as it relates to Swift. As I seek to improve my functional programming thought processes and to prac...

Getting set up to write unit tests in Swift, while not difficult, isn’t exactly intuitive. I’ve written several posts and gathered a few resources on unit testing in Swift, but I haven’t yet published a “getting started” guide until now. Where does one get started with unit testing in Swift when the...

In this unit testing screencast for Swift developers, we explore how to use Test Driven Development to verify method calls. Getting Started Guide If you’re new to unit testing or are trying to get set up with unit testing in a Swift project, you might check out my getting started guide before jumpin...

As I’ve researched Test Driven Development practices in general, and for iOS / Mac applications, I’ve been helped by several sources. I’ve also discovered a few things the hard way, so I’m combining and maintaining this list of resources to help point you in some helpful directions as you adventure ...

Before actually doing Test Driven Development (TDD) for your iOS / Mac app, it’s really important to ask a very fundamental question: What’s the goal? What am I aiming for when I say I want to drive my iOS development with tests? 2 Goals of TDD in iOS A recent course I watched on Pluralsight called ...

“Legacy Swift”.  Is that an odd phrase to you, too? “Legacy” has connotations such as “old”, “difficult-to-change”, “outdated”, etc. Juxtaposing “legacy” and “Swift” would never have crossed my mind until I read Michael Feathers’, Working Effectively With Legacy Code, where he asserts, Legacy code i...

Did you know that you can make any Type (here meaning Class, Enumeration, or Struct), even already-existing ones that you don’t have the source code for, adopt a protocol that it doesn’t normally conform to out of the box? You can – even if you don’t have the original source code for that Type! It’s...

iOS developers will quickly recognize that there are a set of methods that always tend to get implemented when dealing with UITableViews . The problem I consistently face is remembering that set of methods that belong to the UITableViewDataSource (and UITableViewDelegate ) protocols. I find myself o...

After I wrote my post on 7 Reasons You Should Write About Swift, I began to think about some of the roadblocks that hinder blogging. Blog Blockers I started to think about some of my own reservations about blogging, and boiled it down to a couple of big blockers: Time Perfectionism My problems with ...

The challenge when dealing with the presentation and handling of more than one UIActionSheet in a single View Controller is made clear by asking, “How am I going to tell which action sheet I’m dealing with so that I can handle the user’s choice appropriately?” Presumably, the user’s interaction with...

For newcomers to Swift, the concept of extending a Type may be new, so I thought I’d share a high-level overview of Swift extensions in the style of asking the 5 W’s: Who? What? When? Where? Why? Who “Swift developers” is a pretty obvious answer, but here are a scenarios to ask yourself about to see...

In a previous walkthrough on sending e-mails in-app, I explored how to use MFMailComposeViewController to allow a user to compose an e-mail without ever leaving your app. I then followed up with a proposal for better-segregating the responsibilities of composing an e-mail and responding to the deleg...

The process for creating an ASP.Net MVC web application that relies on the Unity Inversion of Control (IOC) container has gotten quite a bit more streamlined since I first started working with it.  However, since I don’t start brand new software projects often, it’s often the case that it takes me a...

If Swift is your iOS/Mac development language of choice, my goal in this post is to persuade you that you should not only write Swift… you should write about Swift. Here are 7 reasons (in the order in which they flowed out of my brain): 1. Swift will never be new again. How amazing is it that every ...

While experimenting with a few things today, I experienced this compiler error: Variable used within its own initial value Let me describe the situation I was in… I was playing (in a playground, no less) with closures, trying to mimic some behavior that I’ve recently learned about in Scala.  Essenti...

Updated on December 14, 2015 – Swift 2.0 + new examples With this post, I intend to wrap up my series on animations as UIView Extensions in Swift… for now.  Truthfully, these ideas flowed out of a real-world app that I was working on, which required various simple animations (fading in/out, sliding ...

Updated on September 19, 2016 – Xcode 8 & Swift 3.0 The goal of this post is to help you grasp the fundamentals of using NSNotificationCenter in your Swift iOS app. The topic isn’t necessarily new, and there’s no difference except syntax between Objective-C and Swift implementations involving NSNoti...

I just spent the last 45 minutes frustrated as to why I was getting the following exception “Input string was not in a correct format.” and “[InvalidCastException: Conversion from string “MMMM dd, yyyy” to type ‘Integer’ is not valid.] I kept thinking to myself, “How hard can this possibly be?!!  I’...

I’ve previously written about using enumerations in Swift to encapsulate special values that could end up falling into the “magic string” category if they were to simply be scattered in-line throughout your code. The primary example I proposed for such a “magic string” replacement was Storyboard Seg...

In a previous post about fade animations in Swift, I demonstrated how to use a class extension to add the ability for any UIView instance to easily call fadeIn() or fadeOut() on itself. This strategy was nice – the animations, while simple, would have cluttered my code each time I used them, had I n...

While iOS 8 is now officially in the wild, it may take a bit of time to reach the level of user adoption that iOS 7 had accumulated over the past year.  If you plan to target the widest number of users for your app (at least in these early days of the iOS 8 roll-out), it’d probably be wise to includ...

As I opened Apple’s latest “Patterns Playground” blog post, I was impressed with the look and feel.  Rather than create the documentation as comment blocks, they managed to put in sharp-looking notes and explanations before each code example / experiment.  It’s like an interactive book, reminiscent ...