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DTFoundation 1.4.1

May 31, 2013

This maintenance update for DTFoundation fixes a few minor issues and adds a new custom-colored disclosure indicator.

Changes

  • ADDED: [DTCustomColoredAccessory] Added left arrow disclosure indicator
  • ADDED: [DTReachability] Demo App
  • CHANGED: [DTReachability] to observe reachability to apple.com instead of general IP connectivity as this addresses some issues where DNS resolving might lag behind
  • FIXED: [DTSidePanel] Appearance Notifications not sent to replaced panels

Thanks to Carl Kabbe for contributing the left arrow disclosure indicator for DTCustomColoredAccessory. I have no idea for which scenario you might need that, but now we have all 4 directions.

The DTSidePanel Appearance notification fix is dedicated to René Pirringer who is using this component in a commercial app. Thus he’s rigorously testing it and found that when programmatically changing the center panel it wouldn’t get the proper notifications.

Appearance Notifications

A view controller which appears should always get these notifications, in this order:

  1. willMoveToParentViewController:
  2. viewWillAppear:
  3. viewDidAppear:
  4. didMoveToParentViewController:

The same order is true for disappearing, but there the new parent view controller will be nil. The whole thing gets slightly more confusing if you are embedding a view controller inside a UINavigationController since this sends the willMove right away, but the other 3 notifications only when the navigation controller actually appears on screen.

Reachability: Name vs. IP

A user of AutoIngest for Mac reported that he would be getting error messages from the synchronizing right after waking up his MacBook. Apparently on some Macs there is a time interval between TCP/IP connectivity being established and when DNS names can be resolved. Thanks to Nick Lockwood (who made FXReachability, where I gleaned this better method) I was able to figure out a better method for Reachability.

Consider the before/after:

// BEFORE - thanks Erica Sadun
BOOL ignoresAdHocWiFi = NO;
 
struct sockaddr_in ipAddress;
bzero(&ipAddress, sizeof(ipAddress));
ipAddress.sin_len = sizeof(ipAddress);
ipAddress.sin_family = AF_INET;
ipAddress.sin_addr.s_addr = htonl(ignoresAdHocWiFi ? INADDR_ANY : IN_LINKLOCALNETNUM);
 
/* Can also create zero addy
   struct sockaddr_in zeroAddress;
   bzero(&zeroAddress, sizeof(zeroAddress));
   zeroAddress.sin_len = sizeof(zeroAddress);
   zeroAddress.sin_family = AF_INET; 
*/
 
_reachability = SCNetworkReachabilityCreateWithAddress(kCFAllocatorDefault, (struct sockaddr *)&ipAddress);
 
// AFTER - thanks Nick Lockwood
_reachability = SCNetworkReachabilityCreateWithName(kCFAllocatorDefault, "apple.com");

Not only is the whole creation of the reachability observer much more compact, it also solves the DNS lag problem. I have to admit, that I didn’t actually test for differences, but I trust Nick.

To simplify use even further I added a macro for determining the internet connectivity status from the SCNetworkConnectionFlags:

// macro to determine reachability status from connection flags
#define DTReachabilityIsReachableFromFlags(connectionFlags) ((connectionFlags & kSCNetworkFlagsReachable) && !(connectionFlags & kSCNetworkFlagsConnectionRequired))

With this macro the demo app’s View Controller becomes very simple:

@implementation ViewController
{
   id _observer; // reference for reachability observer
}
 
- (void)viewDidLoad
{
   [super viewDidLoad];
 
   // register a reachability observer
 
   __weak ViewController *weakself = self;
   _observer = [DTReachability addReachabilityObserverWithBlock:^(SCNetworkConnectionFlags connectionFlags) {
 
      // update label based on connection flags
 
      if (DTReachabilityIsReachableFromFlags(connectionFlags))
      {
         weakself.label.text = @"Reachable";
         weakself.label.textColor = [UIColor greenColor];
      }
      else
      {
         weakself.label.text = @"Not Reachable";
         weakself.label.textColor = [UIColor redColor];
      }
   }];
}
 
- (void)dealloc
{
   [DTReachability removeReachabilityObserver:_observer];
   _observer = nil;
}
 
@end

As usual the update is available direct from the GitHub repository or via CocoaPods.

Categories: Updates

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