#TIKQDirectoryWatcher A class to watch one or more directories, and post notifications when changes occur to their contents

Tim Isted
http://www.timisted.net
Twitter: @timisted

##License TIKQDirectoryWatcher is offered under the MIT license. See the LICENSE file for full details.

##Summary TIKQDirectoryWatcher makes use of kqueues to post notifications when changes occur to the contents of one or more specified directories.

##Basic Usage Add the TIKQDirectoryWatcher.h and .m files to your project, and create an instance:

TIKQDirectoryWatcher *directoryWatcher = [[TIKQDirectoryWatcher alloc] init];

Add one or more directories to watch:

BOOL success = [directoryWatcher watchDirectory:[@"~/Documents" stringByExpandingTildeInPath] error:nil];

This method will return NO if the watcher can't find the specified directory, or if any other error occurs. At the moment, the NSError object is ignored, but will be configured soon. For now, errors are simply logged to the console.

Finally, you'll need to schedule the watcher on the run loop:

success = [directoryWatcher scheduleWatcherOnMainRunLoop:&anyError];

###Notifications You'll need to register to receive kTIKQDirectoryWatcherObservedDirectoryActivityNotification notifications when changes occur:

[[NSNotificationCenter defaultCenter] 
 addObserver:self 
    selector:@selector(notificationHandlerMethod:) 
        name:kTIKQDirectoryWatcherObservedDirectoryActivityNotification 
      object:directoryWatcher];

The notification's user info dictionary contains two entries:

• kTIKQDirectory specifies the name of the directory using a tilde (~) if appropriate, such as ~/Documents
• kTIKQExpandedDirectory specifies the full name of the directory, such as /Users/bob/Documents

##Examples Both a sample Mac application and a sample iOS project are included.

###Mac Example If you do not use Dropbox, you'll need to modify the Mac application observed directories to exclude the ~/Dropbox, otherwise you'll see an error in the console when the application tries to watch that directory. The observed directories are specified in the startWatching: method in DirectoryWatcherAppDelegate.m.

To test for notifications, add or remove a file at the root level of /tmp or ~/Dropbox.

###iOS Example The iOS example checks for changes made in the application's /Documents and /tmp directories. Click the relevant button to add new files to these locations, and trigger the notifications as long as the watcher is enabled.

The Info.plist has UIFileSharingEnabled set to YES. When running on a device (iOS 3.2/4 or higher), try adding a file to the application's /Documents directory using the File Sharing option under the device's Apps tab in iTunes.

##Acknowledgements Some portions of this code are based on Chapter 15, kqueues, of Advanced Mac OS X Programming (Second Edition) by Mark Dalrymple and Aaron Hillegass.

##To Do List

• Fill out NSError objects if errors occur
• Check for memory leaks if errors occur