I’ve made an archive of all my public activity on twitter, from 2009 to 2022. I’ve fully switched to mastodon more than two years ago,…

There’s been some discussion around the iPad’s multitasking user interface, i.e., “how to do several things at once on an iPad?”. The general feeling is…

English title, if I ever translate it: “A brief history of french/european daylight saving time policies”. Ce post reprend un thread twitter d’octobre 2016. Quitte…

1 When accessing resources from my code, I sometimes need to specify the current bundle, but the existing API isn’t great. Here’s an alternative. Apps…

If you’re familiar with Cocoa developement, you probably know what UserDefaults are. Otherwise, a quick recap: (NS)UserDefaults is the macOS/iOS/tvOS name for “user preferences”. The…

1Raise your hand if you’re an Objective-C developer and you’re sick of writing this: if([obj respondsToSelector:@selector(foo)]) { id foo = [obj foo]; } Unless you’ve…

This is the blogpost version of a talk at Cocoaheads Paris in December 20151. TL;DR: 17-second video at the end. – A few months ago,…

This is Objective-C: @interface NSArray (Map) DefineMethod(map, id (^)(id), NSArray*); DefineMethod(reduce, id (^(^)(id))(id), NSArray*); @end @interface NSString (Funcs) DefineProperty(uppercaseString, NSString*); DefineMethod(plus, NSString*, NSString*); @end int…

Apple isn’t really famous for its contributions to open source projects: its latest major effort was Mac OS forge. As the name implies, it dates…

When I started working as a software engineer ten years ago, I was tasked to write the Mac version of an existing project, and I…

In the previous post I mentioned a code pattern frequently used in tests: Run the RunLoop until something specific happens. I’ve written and rewritten this…

Here’s a subject that’s rarely discussed amond developers, even though it’s one of the most important component of all apps: Run Loops. Run loops are…

English/TL;DR The rules of french punctuation require a thin space before some marks. However, there’s no easy way to insert a thin space, so most…

A few weeks ago, I stumbled upon these private methods on NSObject: @interface NSObject (Private) -(id)_ivarDescription; -(id)_shortMethodDescription; -(id)_methodDescription; @end They can be used to obtain…

I often write small tests programs in Objective-C, to experiment stuff or play with something. Most of the time, I put everything in the main.m…

Great news Mac and iOS developers! You don’t have to upload screenshots manually to iTunes Connect anymore. There’s an Apple-provided tool to help you! It…

The Objective-C collections classes from Foundation, NSArray, NSSet and NSOrderedSet, already support various forms of functional-style programming. First, and probably oldest, is: [NSArray makeObjectPerformSelector:] Key-Value…

Yet another little objective-C hack, for when you just want to count: for (NSNumber * num in [@2 to:@4]) { // do something with num…

A few months ago, I made this cool looking View Controller animation for my app Bicyclette. I was tired of the “Horizontal Flip” animation, and…

Here’s a little experiment I made last week. It’s an alternative syntax for Key-Value Coding, which is, as you may know, one of my favorite…

I recently had to debug a complex Responder Chain-related bug: Did you know that when you send a nil-targeted action message, but there’s no first…

TL;DR: Don’t declare IBOutlets using @property (weak) anymore. Just use private ivars: ARC will take care of the rest. ## IBOutlets are, as the name…

Here’s an NSArray Category I’ve used in every single Cocoa project in the last seven years.1 What it does is quite simple, and you can…

I really, really suck at shell scripting. I don’t do it quite often, hopefully, but I’d like to write scripts in a more modern language.…

This week’s post is about a UI widget you’ve already seen dozens of time today: Please wait, I'm loading stuff. Everyone who’s used a computer…

Even with the current trend of gesture-based interfaces, every app needs a button here and there. The UIKit class for buttons is called UIButton and…

Key-Value Coding is an Objective-C mechanism for introspection and (limited) Higher Order Messaging. If you don’t already know about it, you should read the documentation,…

The best app for Vélib is growing bigger! Bicyclette 2 is almost ready, and it needs your help! Register for the beta here. It now…

In iOS apps, we write Custom Views all the time. For example, CocoaControls has a nice collection of custom views. However, it’s sometimes a tedious…

When coming from another language, strings in Objective-C are surprising on one aspect : objects of the string class, NSString are immutable : their value…

I like that name, don’t you? bou.io There’s a ton of subjects I want to write about, so hopefully this will not stay empty too…