Monitoring File Changes in Adobe AIR
I have just uploaded a new class to the as3corelib library that makes it easy to monitor files for changes.
The class is called FileMonitor, and is in the com.adobe.air.filesystem package. Here is a simple example of it in use:
import com.adobe.air.filesystem.FileMonitor;
import flash.filesystem.File;
import flash.events.Event;
import com.adobe.air.filesystem.events.FileMonitorEvent;
private var monitor:FileMonitor;
private function onSelectButtonClick():void
{
var f:File = File.desktopDirectory;
f.addEventListener(Event.SELECT, onFileSelect);
f.browseForOpen("Select a File to Watch.");
}
private function onFileSelect(e:Event):void
{
var file:File = File(e.target);
if(!monitor)
{
monitor = new FileMonitor();
monitor.addEventListener(FileMonitorEvent.CHANGE, onFileChange);
monitor.addEventListener(FileMonitorEvent.MOVE, onFileMove);
monitor.addEventListener(FileMonitorEvent.CREATE, onFileCreate);
}
monitor.file = file;
monitor.watch();
}
private function onFileChange(e:FileMonitorEvent):void
{
trace("file was changed");
}
private function onFileMove(e:FileMonitorEvent):void
{
trace("file was moved");
}
private function onFileCreate(e:FileMonitorEvent):void
{
trace("file was created");
}
Note that the class broadcasts three events:
- FileMonitorEvent.CHANGE : Broadcast when the contents of a monitored file changes. This is currently based on the timestamp of the file.
- FileMonitorEvent.MOVE : Broadcast when a monitored file is moved or deleted.
- FileMonitorEvent.CREATE : Broadcast when a monitored file is created (since you can have a File instance that points to a file that does not exist).
The new classes are not yet in the as3corelib builds, but if you want to play with them, you can grab them from the project source.
Note, that I am working on updating the unit tests for the library, so if you run the test runner from source, some of the tests will fail. This should be fixed in a couple of days.
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