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?
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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. Continue reading “Docset Viewer: Resuming large downloads with NSURLConnection”

Using GCD and Blocks Effectively

With iOS 4.0 Apple introduced two new technologies to the iOS platform: Grand Central Dispatch, and blocks.  Simply put, it is to multi-threaded programming what fire is to a barbecue.  Sure you can do without it, but the end result is much better.

Despite all this, developers still seem to avoid using it. Some of the reasons for this, off the top of my head, could be backwards-compatibility for older versions of iOS, unfamiliarity with the funky syntax it uses, or simply a lack of practice.  The biggest thing I find however is a general misunderstanding about the importance of multi-threading among new developers, which was made worse by the difficulty of dealing with threads before blocks and GCD was released.

Fortunately there’s no reason to avoid multi-threaded programming in iOS, but before I dive into the specifics I’d like to point out just how important it is to use an asynchronous approach to development on iOS, or any mobile platform in general.
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Smarter and More Reusable Core Data

Like most developers, I look to Apple’s default application templates to get up-to-speed on what would appear as being the Right Way™ of developing apps on iOS. In practice however what you need to realize is Apple’s templates are meant to be the easiest introduction to a set of tools that can be fairly complicated for beginners to understand.  Core Data is one of those areas. The problem is when you try to grow your application you’ve built on top of Apple’s sample template. You’ll experience some annoying growing pains, and will need to give your code a thorough washing and a fresh coat of wax to be able to mature your application.

In my code I’ve learned to share and reuse my classes with other applications I’m writing by encapsulating a lot of the boilerplate into reusable classes, as well as wrapping my whole Core Data model in a reusable static library. This wasn’t the most intuitive thing to get right, but now that it’s done it was really worth the effort. Let me show you how it’s done.

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Building iOS apps for Over-The-Air AdHoc distribution

I’ve written about building iOS applications with Hudson Jenkins, but until recently there hasn’t been a convenient way of getting those applications to your testers. Of course the most important part of your build output will be the app bundle you send to Apple’s iTunes Connect web interface, but throughout your development cycle you’ll want to test your app.  Sure you could build and deploy a debug build straight to your own personal device, but you get the most benefit from having other people beta test your app.

With recent releases of Xcode and the iOS SDK, Apple improved their AdHoc distribution support with two main enhancements:

  1. Mobile provisioning files can now be embedded in the App’s IPA itself, meaning you don’t have to maintain and update separate .mobileprovision files separately;
  2. A specially-formated manifest Plist file can be created that, when linked to properly, allows test devices to install new versions of your AdHoc app without needing to plug into a computer to sync the app using iTunes.

These improvements are huge, but require some changes to your build scripts and your Continuous Integration environment.  I’d like to show you how to do this in your own installations, and show you some options for how to distribute your apps to your testers.

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Animating Interfaces with Core Animation: Part 4

This is the fourth in a series of posts I’m writing on animating iOS interfaces using Core Animation. In the first post I created a planetary orbit demo using nested CALayer objects. The second post showed how to dress up a UI by animating an image. The third post shows how you can trigger animations in response to button actions.

This post will show how you can create the beginnings of a full game using Core Animation combined with CAShapeLayer and UIBezierPath objects.

Read on to see more

Continue reading “Animating Interfaces with Core Animation: Part 4”