Jeff Kelley’s Blog

Slides: Using and Creating Images in iOS at MobiDevDay Detroit

Today was MobiDevDay in Detroit, and it was a heck of a good conference (and I’m not just saying that because Detroit Labs helped put it on). The slides from my presentation are on Speaker Deck, and you can see AmazeKit on GitHub or view its documentation. Enjoy!

Video From My Strange Loop “Concurrency in iOS” Talk

InfoQ has posted the video from my Strange Loop talk. Enjoy!

Slides, Code From My CodeMash 2013 Presentation

At CodeMash 2013, I gave a talk entitled “Using Images in iOS.” Sorry for the delay, but here are some links for the contents of the presentation:

Also, during this presentation I open-sourced a graphics library called AmazeKit. Follow the link to check it out, or read more about it on the Detroit Labs tumblr.

Remote Nib Loading for Fun (But Not Profit)

A while ago I noticed an interesting API for creating a UINib object from data:

+ (UINib *)nibWithData:(NSData *)data bundle:(NSBundle *)bundleOrNil

At the time I didn’t have a use for it, until this exchange occurred on Twitter:

Other things you can externalize for remote updates: Error messages and codes; refresh / download policies; AutoLayout visual language.
— Sentius Magnus (@drance) January 2, 2013

@drance You can make a UINib from an NSData, so theoretically you could download remote nibs too.
— Jeff Kelley (@SlaunchaMan) January 2, 2013

The resulting exchange was very fruitful, including this gem from ex-Apple employee Michael Jurewitz:

@drance now you’re just asking for rejection. // @SlaunchaMan
— Michael Jurewitz (@Jury) January 2, 2013

So I wouldn’t recommend using this in a shipping application, but I wanted to see if it worked. I created a simple app that loads a nib from a website, then tries to initialize a view controller’s view using it. You can view the whole project on GitHub, but here’s the relevant code:

// // JKAppDelegate.m // RemoteNibLoading // // Created by Jeff Kelley on 1/2/13. // Copyright (c) 2013 Jeff Kelley. All rights reserved. // #import "JKAppDelegate.h" #import "JKLoadingViewController.h" #import "JKRemoteNibViewController.h" static NSString * const kRemoteNibURL = @"http://www.slaunchaman.com/JKRemoteNibViewController.nib"; @implementation JKAppDelegate - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { [self setWindow:[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]]]; [[self window] setBackgroundColor:[UIColor whiteColor]]; [[self window] makeKeyAndVisible]; JKLoadingViewController *loadingViewController = [[JKLoadingViewController alloc] initWithNibName:nil bundle:nil]; [[self window] setRootViewController:loadingViewController]; // Load the remote nib NSURL *remoteNibURL = [NSURL URLWithString:kRemoteNibURL]; NSURLRequest *nibRequest = [NSURLRequest requestWithURL:remoteNibURL cachePolicy:NSURLRequestReloadIgnoringLocalCacheData timeoutInterval:60.0]; [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:YES]; [NSURLConnection sendAsynchronousRequest:nibRequest queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *error) { [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:NO]; if (data) { UINib *remoteNib = [UINib nibWithData:data bundle:nil]; if (remoteNib) { JKRemoteNibViewController *remoteNibViewController = [[JKRemoteNibViewController alloc] init]; // Load the nib, which will set up the view controller bindings [remoteNib instantiateWithOwner:remoteNibViewController options:nil]; [[self window] setRootViewController:remoteNibViewController]; } else { [[[UIAlertView alloc] initWithTitle:@"Error" message:@"Could not create nib from data." delegate:nil cancelButtonTitle:@"Aww, shucks." otherButtonTitles:nil] show]; } } else { if (error) { [[[UIAlertView alloc] initWithTitle:@"Error" message:[error localizedDescription] delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil] show]; } } }]; return YES; } @end

Would I recommend using this in a shipping app? Absolutely not, given Jury’s recommendations. But it is an interesting idea for enterprise, in-house, or jailbreak apps, and I can see the possibility for some very cool stuff to come out of it.

Slides, Code for my Concurrency in iOS Strange Loop Talk

I gave a talk at the awesome Strange Loop conference today about concurrency in iOS. You can view the slides on SpeakerDeck, and see the Grand Central Dispatch and NSOperationQueue code samples on GitHub. Thanks to everyone who attended!