Adobe Air - Read updates to File with FileStream

Question

I'm trying to get two different apps to communicate through a file. I would like app 1 to append some text to a file, and app 2 to notice, and read the new bytes (not the whole file).

There is an event, ProgressEvent.PROGRESS, that is supposed to fire when new data is available on a FileStream, but it only fires when I first open the file.

Basically, I would like to leave the FileStream open, listening like a socket on the end of that file for changes. Is it possible? Any performance considerations?

Thanks1

Answer 1

I'd say keep a record of the filesize, check it periodically with a Timer, and then seek to the end of the old file when it gets bigger. With AIR 2.0 it should be easy, if you embed something akin to "tail -f".

Answer 2

You can use the FileMonitor class that is part of Adobe's 'as3corelib' package to monitor files.

http://code.google.com/p/as3corelib/

It comes with FileMonitorEvent.CHANGE, MOVE and CREATE events.

Presentation and example here :

http://www.mikechambers.com/blog/2009/03/11/monitoring-file-changes-in-adobe-air/

Answer 3

I understand that you probably want the socket-like 'interface' for reading/writing files between two apps, but you may be able to accomplish the same thing with a local SharedObject and a 'manager' class that uses the localConnection class to do certain things to that sharedObject/file. Random thought....