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# Reachability

This is a drop-in replacement for Apple's `Reachability` class. It is ARC-compatible, and it uses the new GCD methods to notify of network interface changes.

In addition to the standard `NSNotification`, it supports the use of blocks for when the network becomes reachable and unreachable.

Finally, you can specify whether a WWAN connection is considered "reachable".

*DO NOT OPEN BUGS UNTIL YOU HAVE TESTED ON DEVICE*

## Requirements

Once you have added the `.h/m` files to your project, simply:

* Go to the `Project->TARGETS->Build Phases->Link Binary With Libraries`.
* Press the plus in the lower left of the list.
* Add `SystemConfiguration.framework`.

Boom, you're done.

## Examples

### Block Example

This sample uses blocks to notify when the interface state has changed. The blocks will be called on a **BACKGROUND THREAD**, so you need to dispatch UI updates onto the main thread.

	// Allocate a reachability object
	Reachability* reach = [Reachability reachabilityWithHostname:@"www.google.com"];

	// Set the blocks
	reach.reachableBlock = ^(Reachability*reach)
	{
		// keep in mind this is called on a background thread
		// and if you are updating the UI it needs to happen
		// on the main thread, like this:

		dispatch_async(dispatch_get_main_queue(), ^{
		  NSLog(@"REACHABLE!");
		});
	};

	reach.unreachableBlock = ^(Reachability*reach)
	{
		NSLog(@"UNREACHABLE!");
	};

	// Start the notifier, which will cause the reachability object to retain itself!
	[reach startNotifier];

### `NSNotification` Example

This sample will use `NSNotification`s to notify when the interface has changed. They will be delivered on the **MAIN THREAD**, so you *can* do UI updates from within the function.

In addition, it asks the `Reachability` object to consider the WWAN (3G/EDGE/CDMA) as a non-reachable connection (you might use this if you are writing a video streaming app, for example, to save the user's data plan).

	// Allocate a reachability object
	Reachability* reach = [Reachability reachabilityWithHostname:@"www.google.com"];

	// Tell the reachability that we DON'T want to be reachable on 3G/EDGE/CDMA
	reach.reachableOnWWAN = NO;

	// Here we set up a NSNotification observer. The Reachability that caused the notification
	// is passed in the object parameter
	[[NSNotificationCenter defaultCenter] addObserver:self
											 selector:@selector(reachabilityChanged:)
												 name:kReachabilityChangedNotification
											   object:nil];

	[reach startNotifier];

## Tell the world

Head over to [Projects using Reachability](https://github.com/tonymillion/Reachability/wiki/Projects-using-Reachability) and add your project for "Maximum Wins!".