Objective-C

Working with multiple architectures & compiled binaries

When working with iOS apps (or really anything within Apple’s ecosystem) I’ve sometimes found the need to deeply introspect the libraries and executables built in my project to answer questions like “Is bitcode enabled for all architectures?” or “Which architectures was this binary compiled for”, and so forth.

These aren’t easy questions to answer unless you know your way around the command-line, and which commands to invoke. So I thought I’d go over how to analyze compiled binaries, and share some helpful scripts I wrote to simplify the process.

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LLVM Module Maps to the rescue!

I recently wrote about Cocoa / Cocoa Touch frameworks, and in writing about it I was sorely tempted to dive into Modules, since they are pretty important to modern frameworks. But it was such a huge topic, I decided to break it out into a separate post.

In a nutshell, LLVM Module Maps were invented as a way to improve how source code imports other frameworks.

If you’ve ever worked on traditional C/C++ software projects (Makefile, CMake, gcc…any of these ring a bell?) you’ll know that the more code you add, the longer it takes to build, and the more likely you are to have conflicting types or macro definitions.

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Cocoa Dynamic Frameworks

If you don’t know the nuts and bolts of how your code is compiled, linked, and executed on target devices, you aren’t alone. And lets be honest, this is perfectly fine! That’s the great thing about abstraction: not everyone need be an expert at everything in order to be effective.

There are times though where a little bit of knowledge can go a long way to help troubleshoot particularly onerous problems. So I thought I’d explain a bit about how apps work in Cocoa (and by extension, Cocoa Touch), particularly how frameworks work.

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Logging with CocoaLumberjack and TestFlight

Consider the following situation that happens far too often in mobile app development: You’ve just released an app that works perfectly for you, and you’ve tested it extensively. You’re proud of your accomplishments and submit the app to the world, only to have several emails sent to you from users who have nothing but difficulties in running the app. You send a bug fix release to the App Store, but since you’re still unable to reproduce the problem you’re at the whim of luck and end-user feedback. You can hope your users know how to send you a crash report, but what if the app isn’t actually crashing? Wouldn’t it be great to be able to access your app’s log information from that client to be able to troubleshoot the problems?
Read More »Logging with CocoaLumberjack and TestFlight

Docset Viewer v1.2 and how to customize iCloud backups

I’ve recently released version 1.2 of Docset Viewer, which fixes a number of bugs people experienced with the previous version. If you had problems with the previous release, please give this one a try.

One of the improvements I’ve added is the ability to customize whether or not you would like to back up your Docsets (which can get quite large) into iCloud. To keep with the instructional nature of this site, I’ll show you how you can do that in your own apps.
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Docset Viewer: Resuming large downloads with NSURLConnection

As I’ve shown in my previous post announcing Docset Viewer, I want this series of posts to be more than me talking about my new app. In keeping with the instructional nature of my site, I’m going to show you a few things that I did in my new app Docset Viewer and how I put it together. This time around I’m going to show how I use NSURLConnection for downloading large files, and even resuming them.

In Docset Viewer I’ve added the ability to download docsets directly from Atom feeds, either from custom URLs or from a pre-configured list of Apple’s available docsets. Since you may not be consistently connected to the Internet, it’s important to be able to download documentation packages incrementally, especially since they can be anywhere from 300MB to 500MB.Read More »Docset Viewer: Resuming large downloads with NSURLConnection

Announcing Docset Viewer v1.1 for iPad and iPhone

Over the years my blog has transformed from the usual “Wordy geek ranting about first-world problems” content toward more educational and informative posts on what I do for a living: developing awesome iOS applications. I don’t usually talk about the actual applications I’m writing though, since most of my work is on other people’s apps (and I’m not allowed to spill the beans on anything fun). I still consider myself an “Indie” developer though, and just like many other developers out there, I like to solve the problems that I myself face on a daily basis.

In this case what started with me complaining on Twitter turned into a new app due to the resounding and immediate “Me too!” responses I got from some of my followers. And with that I decided to create Docset Viewer.

Read More »Announcing Docset Viewer v1.1 for iPad and iPhone

Core Graphics isn’t scary, honest!

For anyone who’s developed exclusively with UIViews on iOS may take the title of this post a bit oddly. “WHAT?!” they might say, “Are you insane? Core Graphics is not only a C-only API, but has confusing function names, and needs way more code to do the same thing I can do in less code in UIView”.  Yes, they might be right, but there’s a reason why Core Graphics exists. It’s FAST!

But using Core Graphics doesn’t mean that your code has to be confusing, or that you have to compromise flexibility for performance. You can have your cake and eat it too (aka you can have high-performing code that is easy to read). Read on to see what I mean.
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Back To Basics: Simple debugging tips in Xcode

As developers we spend most of our lives dealing with broken and barely-functional software: our own software. We do our best to make the applications we develop somewhat less broken and try to add features to make it functional. And once we finally get our software working bug-free and functioning stably, what do we do? Do we bask in the joy of a stable app and spend countless hours enjoying that moment? No, we move on to v1.1 or v2.0, adding more features and consequently more bugs.  It’s kind of sad if you think about it.

Since much of our lives are spent with applications in various states of brokenness, understanding how to debug our software and catch those exceptions that arise is vital to getting our applications to a stable state so we can release, consequently moving on to create a whole new set of bugs that need to be fixed.

Here are some basic tips and tricks to make your life easier dealing with Xcode 4, and tracking down those places where your code runs off into the bushes.
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