Yet another "local file access in actionscript-3" q-u-e-stion - actionscript-3

Question

I hope I can get some help with my actionscript problem.
(inb4: 'What exactly are you trying to accomplish (other than opening an arbitrary file without user permission)?' link)
I am trying to assist with student exercises - so I thought I'd come up with an example of a random gallery. The idea with this would be that students would be able to generate a SWF file, and in the same directory, they would have a folder with images. Then the SWF movie would read the contents of the directory; choose a random image, and display it.
I would have hoped that this could be done both locally (while students develop) - and, should they choose so, they should be able to upload the entire directory online -- and hopefully, the example would work either way. That turns out not to be so easy - so these are my questions:
They say, that in order to get local directory listing, I should use AIR - what does that mean? Is there some executable - other than flashplayerdebugger - that I should call in order to reproduce the SWF if it uses AIR?
Is it possible to get a local directory listing without using this AIR (in the similar vein as the Flex code below?)
It seems I can load a local text file; but I cannot load a local bitmap file. Would it be possible to load a bitmap file as well?
How can you give local access permission to files/folders, if it so happens that you don't have access to the Internet, so you cannot access settings_manager04.html - but you'd like to use a Flash application both with local files and with network sockets on the local network?
Now, one thing is that most students work with Flash CSx versions - I on the other hand am on Linux, so I have tried to make a Flex example; so I've provided the example as Flex code, but I'd like to know possible answers for the Flash CS environment too. The directory structure, compile lines, and code is given at end of this post - but here is how the "application" directory looks like:
Ok, so here is the problem in a bit more detail. First, I thought I'd try to read the directory contents - so I tried the code here: AS3 Basics: List all files in a folder including subdirectories (AIR ... on students' Flash CS - but that seemed to fail miserably.
So I thought - OK, then let's put in a text file in the same directory as the .swf, which will contain a list of the images; e.g.
cat > fileslist.txt <<EOF
img/01.jpg
img/02.jpg
EOF
Then, the Flash app would read this file first - and then proceed to choose a random image from the contents. But at the very first instant, I get:
An ActionScript error has occurred:
SecurityError: Error #2148: SWF file file:///home/rgaltest/rgaltest.swf cannot access local resource file:///home/rgaltest/fileslist.txt. Only local-with-filesystem and trusted local SWF files may access local resources.
at flash.net::URLStream/load()
at flash.net::URLLoader/load()
at rgaltest()[/home/rgaltest/rgaltest.as:23]
So, the answer to this seems to be:
"If you are getting that error when using flash.net.URLLoader and the free flex compiler, add the following option when you compile to get your swf to work: -use-network=false" (juicy tidbits - Only local-with-filesystem and trusted local SWF files may access local resources.)
"Turns out the solution is to configure your Flash Player to trust the swfs in the project’s /bin-debug directory ... 1) Goto http://www.macromedia.com/support/documentation/en/flashplayer/help/settings_manager04.html ... " (Solution – Error #2010: Local-with-filesystem SWF files are not permitted to use sockets. » Mark Lapasa)
Now, I would not like to have -use-network=false - because students may need to integrate other network based stuff in that example. Then again, something similar to that "settings_manager04.html" ("Global Security Settings panel") page shows up if you open the SWF in a browser, then right-click, then choose "Global Settings" - but does it work for SWF files being shown as a part of Ctrl-Enter build in Flash CS (or correspondingly, those that are open with flashplayerdebugger?) So I try it - choose "Edit Locations", "Browse for folder", choose /home/rgaltest under "Always Allow":
... and now the fileslist.txt gets loaded alright; also when the .swf is ran with flashplayerdebugger.
Right, so now that the files list is loaded, I'd proceed on loading the bitmaps.. so I add the respective code (with onImgLoaded etc), and this is what I get in the log:
At frame #1
file onTextLoaded: img/01.jpg,img/02.jpg,
At frame #2
file onImgLoaded: [object URLLoader]
TypeError: Error #1034: Type Coercion failed: cannot convert "ÿØÿà
...
¿ÿÙ" to flash.display.Bitmap.
at rgaltest/onImgLoaded()[/home/rgaltest/rgaltest.as:64]
at flash.events::EventDispatcher/dispatchEventFunction()
at flash.events::EventDispatcher/dispatchEvent()
at flash.net::URLLoader/onComplete()
At frame #3
At frame #4
...
Interestingly - the image did get read - as all of its binary contents are dumped to the log! Yet, it cannot be interpreted as bitmap data???!
First of all, this is my directory layout:
mkdir /home/rgaltest
cd /home/rgaltest
touch rgaltest.as
touch fileslist.txt
mkdir img
cd img
convert -size 320x240 gradient:\#4b4-\#bfb 01.jpg
convert -size 320x240 gradient:\#b44-\#bff 02.jpg
chmod -R 777 /home/rgaltest # to ensure no problem with file permissions
The rgaltest.as is given below; I compile that with:
/path/to/flex_sdk_4.6.0.23201_mpl/bin/mxmlc -static-link-runtime-shared-libraries -use-network=true -verbose-stacktraces -debug=true rgaltest.as
... and I check that locally with (make sure mm.cfg is properly set up, see also Using Flash Player debugger):
# in one terminal:
tail -f ~/.macromedia/Flash_Player/Logs/flashlog.txt
# in another terminal:
/path/to/flashplayer_11/flashplayerdebugger rgaltest.swf
And finally, here is rgaltest.as:
package {
import flash.display.Sprite;
import flash.text.TextField;
import flash.display.MovieClip;
import flash.events.Event;
import flash.events.IEventDispatcher;
import flash.net.*; //URLLoader;
import flash.display.Bitmap;
import flash.display.BitmapData;
[SWF(width="550", height="400")]
public class rgaltest extends MovieClip {
public var _pictureArray:Array;
public var frameCnt:Number = 0;
public var myTextLoader:URLLoader;
public var isFileslistLoaded:Boolean = false;
public var myImgLoader:URLLoader;
public var isImgLoading:Boolean = false;
// constructor - create/initialize objects here
public function rgaltest() {
this.stage.frameRate = 10; // frames per second
// load the text file with image list
myTextLoader = new URLLoader();
myTextLoader.addEventListener(Event.COMPLETE, onTextLoaded);
myTextLoader.load(new URLRequest("fileslist.txt"));
// add event listener for onEnterFrame
configureListeners(this);
}
private function configureListeners(dispatcher:IEventDispatcher):void {
dispatcher.addEventListener(Event.ENTER_FRAME, my_OnEnterFrame);
}
public function onTextLoaded(e:Event):void {
_pictureArray = e.target.data.split(/\n/);
trace("file onTextLoaded: " + _pictureArray);
isFileslistLoaded = true;
}
public function my_OnEnterFrame(event:Event):void {
frameCnt++;
trace("At frame #" + frameCnt);
if (isFileslistLoaded) {
if (!isImgLoading) {
//load a random image
var rndChoice:Number = Math.floor(Math.random()*2) + 1;
myImgLoader = new URLLoader();
myImgLoader.addEventListener(Event.COMPLETE, onImgLoaded);
myImgLoader.load(new URLRequest(_pictureArray[rndChoice]));
isImgLoading = true;
}
}
} // end onEnterFrame
public function onImgLoaded(e:Event):void {
trace("file onImgLoaded: " + e.target);
var _image:Bitmap = Bitmap(e.target.data);
var _bitmap:BitmapData = _image.bitmapData;
addChild(_image);
}
} //end class
} //end package
Some other relevant links:
flex - Adding Local Filenames/References To Array In Actionscript - Stack Overflow
flash - Is there a way to read local files in ActionScript 3 "silently"'? - Stack Overflow
adobe flash cs4 as3: get current directory of a running project? - Stack Overflow
flex - open local files in AS3 - Stack Overflow

Answer 1

Bump - it seems I solved the bitmap loading (putting it here in separate post, so that I don't clog the OP too much); I just used Loader class instead of URLLoader; see code below (also note the mistake in random calculation in OP, which is corrected below).
Anyways - this is the thing: when I tried the Loader class on the students' Flash CSx, it tended to fail miserably! But, maybe that was because in those cases, we didn't give any permissions to the folder from "settings_manager04.html"? Any special things that should be taken care of, when a code similar to this is generated in Flash?
Here is the reworked rgaltest.as:
package {
import flash.display.Sprite;
import flash.text.TextField;
import flash.display.MovieClip;
import flash.events.Event;
import flash.events.IEventDispatcher;
import flash.net.*; //URLLoader;
import flash.display.Bitmap;
import flash.display.BitmapData;
import flash.display.Loader; //*
[SWF(width="550", height="400")]
public class rgaltest extends MovieClip {
public var _pictureArray:Array;
public var frameCnt:Number = 0;
public var myTextLoader:URLLoader;
public var isFileslistLoaded:Boolean = false;
public var myImgLoader:Loader;
public var isImgLoading:Boolean = false;
// constructor - create/initialize objects here
public function rgaltest() {
this.stage.frameRate = 10; // frames per second
// load the text file with image list
myTextLoader = new URLLoader();
myTextLoader.addEventListener(Event.COMPLETE, onTextLoaded);
myTextLoader.load(new URLRequest("fileslist.txt"));
// add event listener for onEnterFrame
configureListeners(this);
}
private function configureListeners(dispatcher:IEventDispatcher):void {
dispatcher.addEventListener(Event.ENTER_FRAME, my_OnEnterFrame);
}
public function onTextLoaded(e:Event):void {
_pictureArray = e.target.data.split(/\n/);
trace("file onTextLoaded: " + _pictureArray);
isFileslistLoaded = true;
}
public function my_OnEnterFrame(event:Event):void {
frameCnt++;
trace("At frame #" + frameCnt);
if (isFileslistLoaded) {
if (!isImgLoading) {
//load a random image
var rndChoice:Number = Math.floor(Math.random()*2) + 0;
trace("Loading: " + rndChoice + " / " + _pictureArray[rndChoice]);
myImgLoader = new Loader();
myImgLoader.contentLoaderInfo.addEventListener(Event.COMPLETE, onImgLoaded);
myImgLoader.load(new URLRequest(_pictureArray[rndChoice]));
isImgLoading = true;
}
}
} // end onEnterFrame
public function onImgLoaded(e:Event):void {
trace("file onImgLoaded: " + e.target);
var _image:Bitmap = Bitmap(myImgLoader.content);
var _bitmap:BitmapData = _image.bitmapData;
addChild(_image);
}
} //end class
} //end package