How can I get Flash to write data to an external file?

More isn't going to help, since it all boils down to flash writing some data to an external file. An example would be having an online flash game and saving high scores to a data file that can be later read. Another example would be having a flash front end to a database that a user modifies and then is able to store the changes back into the database. You're right - it is a security concern and that's probably why flash doesn't do it natively - wanting to stay in the sandbox. However, it's easy to see where you could have flash make a call to something server-side, a jsp app for example, that would take the variables that flash passes to it that then writes to the local file. I'm just trying to make sure that there's not some easy, elegant way to get to the endpoint that I'm currently overlooking. And then, further, trying to look at some examples to make sure that what I'm envisioning will work like I imagine it will.

Serverside code can't write to a local file, either, except by literally downloading data to the user and saying "here, save this somewhere". At which point it becomes just another file on the user's computer, which is completely inaccessible to that serverside code. That's just the nature of the beast.

augh, mispoke. I'm thinking from the server point of view when I'm thinking of local file. My bad, my bad, not the user's machine, but the server. In my mind, from the flash app's point of view, "I'm being called from this server directory and I want to write to a little file in this same directory as me..." Yeah, wrong frame of reference for this discussion. So, flash app lives on a server, user calls it up in their browser, the flash app wants to write data to a text file on the server when the user saves changes.

Oh, gotcha. Well, I just realized that FlashMX can write to a local file (as in local to the user), in a limited sort of way: for that you want http://www.macromedia.com/support/flash/action_scripts/local_shared_object/local_shared_object05.html. For storing data on the server side, as far as I know you do need a serverside script to catch and store the data, using sendAndLoad to submit form elements to it and/or receive the response.

I had this same question, specifically about how a Flash app or projector (locally) could copy a file from a CD-ROM to a local drive. What I think will work (haven't actually tried it, yet...) is using the http://www.macromedia.com/support/flash/ts/documents/fscommand_projectors.htm#Exec. I think you could use this to fire off an Applescript or shell command to copy a file (or write to a file). This won't work out of a browser, though...

A good place to get answers to Flash ActionScript questions is the newsgroup macromedia.flash.actionscript that is hosted on forums.macromedia.com.

When a Flash app hosted on a Web server requests an external file, does the IP address of that request come from localhost, the server's IP, or the IP of the user viewing the Flash app? If it's either of the first two options, you could add a certain degree of security by only allowing queries to the server-side script from localhost or the server's IP, and ignore/deny all other requests. Ditto for referrers. Does Flash support any sort of encryption for data transmitted in this method? Can Flash access files outside of the web root? IPs and referrers can, of course, be spoofed, but there's a question of whether someone would go through enough effort to spoof them and/or crack the encryption just to write a data file they can't see.

As ook mentions above, http://www.director-online.com/buildArticle.php?id=1082, while limited, do what you want. Alternately, if Shockwave is an option for what you are doing, http://www.macromedia.com/support/director/ts/documents/read_write_text_tips.htm will do something similar (again, in a very limited way), without popping a warning dialog. Danelope: Flash usually runs in the user's browser, so the IP is the user's. Additionally, some popular browsers don't report referers with requests emitted from Flash.

There's several ways of doing this. The flash movie cannot write to a text file on the server directly, you need to go through a server-side setup. I know ASP can read and write text files; i'm sure php can do the same. The basic actionscript would be this type of function: function sendhighscore(thescore) { myVars=new LoadVars(); myVars.highScore=thescore; myVars.send("testpage.asp"); } with testpage.asp doing all the work. LoadVars defaults to POST for sending the data. Email me if you need more help.