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how do you allow javascript communications with Flex/Flash/Actionscript

Well here's a problem.
I've got a website with large javascript backend. This backend talks to a server over a socket with a socket bridge using http://blog.deconcept.com/swfobject/
The socket "bridge" is a Flex/Flash .swf application/executable/plugin/thing for which the source is missing.
I've got to change it.
More facts:
file appExePluginThing.swf
appExePluginThing.swf Macromedia Flash data (compressed), version 9
I've used https://www.free-decompiler.com/flash/ to decompile the .swf file and I think I've sorted out what's the original code vs the libraries and things Flash/Flex built into it.
I've used FDT (the free version) to rebuild the decompiled code into MYappExePluginThing.swf so I can run it with the javascript code and see what happens.
I'm here because what happens isn't good. Basically, my javascript code (MYjavascript.js) gets to the point where it does
window.log("init()");
var so = new SWFObject("flash/MYappExePluginThing.swf"", socketObjectId, "0", "0", "9", "#FFFFFF");
window.log("init() created MYappExecPluginThing!!!");
so.addParam("allowScriptAccess", "always");
log("init() added Param!!");
so.write(elId);
log("init() wrote!");
IE9's console (yeah, you read that right) shows
init()
created MYappExecPluginThing!!!
init() added Param!!
init() wrote!
but none of the debugging i've got in MYappExePluginThing.as displays and nothing else happens.
I'm trying to figure out what I've screwed up/what's going on? Is MYappExePluginThing.as running? Is it waiting on something? Did it fail? Why aren't the log messages in MYappExePluginThing.as showing up?
The first most obvious thing is I'm using FDT which, I suspect, was not used to build the original. Is there some kind of magic "build javascript accessible swf thing" in FlashBuilder or some other IDE?
First noteworthy thing I find is:
file MYappExePluginThing.swf
MYappExePluginThing.swf Macromedia Flash data (compressed), version 14
I'm using Flex 4.6 which, for all I know, may have a completely different mechanism for allowing javascript communication than was used in appExePluginThing.swf
Does anyone know if that's true?
For example, when FDT runs this thing (I can compile but FDT does not create a .swf unless i run it) I get a warning in the following method:
private function init() : void
{
Log.log("console.log", "MYappExePluginThing init()");
//var initCallback:String = Application.application.parameters.initCallback?Application.application.parameters.initCallback:"MYjavascript.MYappExePluginThing_init";
var initCallback:String = FlexGlobals.topLevelApplication.parameters.initCallback?FlexGlobals.topLevelApplication.parameters.initCallback:"MYjavascript.MYappExePluginThing_init";
try
{
ExternalInterface.addCallback("method1Callback",method1);
ExternalInterface.addCallback("method2Callback",method2);
ExternalInterface.call(initCallback);
}
catch(err:Error)
{
Log.log("console.log", "MYappExePluginThing init() ERROR err="+err);
}
}
I got a warning that Application.application was deprecated and I should change:
var initCallback:String = Application.application.parameters.initCallback?Application.application.parameters.initCallback:"MYjavascript.MYappExePluginThing_init";
to:
var initCallback:String = FlexGlobals.topLevelApplication.parameters.initCallback?FlexGlobals.topLevelApplication.parameters.initCallback:"MYjavascript.MYappExePluginThing_init";
which I did but which had no effect on making the thing work.
(FYI Log.log() is something I added:
public class Log{
public static function log(dest:String, mssg:String):void{
if(ExternalInterface.available){
try{
ExternalInterface.call(dest, mssg);
}
catch(se:SecurityError){
}
catch(e:Error){
}
}
trace(mssg);
}
}
)
Additionally, in MYjavascript.js MYappExePluginThing_init looks like this:
this.MYappExePluginThing_init = function () {
log("MYjavascript.js - MYappExePluginThing_init:");
};
Its supposed to be executed when MYappExePluginThing finishes initializing itself.
Except its not. The message is NOT displaying on the console.
Unfortunately, I cannot find any references explaining how you allow javascript communication in Flex 4.6 so I can check if I've got this structured correctly.
Is it a built in kind of thing all Flex/Flash apps can do? Is my swf getting accessed? Is it having some kind of error? Is it unable to communicate back to my javascript?
Does anyone have any links to references?
If this was YOUR problem, what would you do next?

(Not a full solution but I ran out of room in the comment section.)
To answer your basic question, there's nothing special you should need to do to allow AS3-to-JS communication beyond what you've shown. However, you may have sandbox security issues on localhost; to avoid problems, set your SWFs as local-trusted (right-click Flash Player > Global Settings > Advanced > Trusted Location Settings). I'm guessing this not your problem, though, because you'd normally get a sandbox violation error.
More likely IMO is that something is broken due to decompilation and recompilation. SWFs aren't meant to do that, it's basically a hack made mostly possible due to SWF being an open format.
What I suggest is that you debug your running SWF. Using break-points and stepping through the code you should be able to narrow down where things are going wrong. You can also more easily see any errors your SWF is throwing.

Not really an answer, but an idea to get you started is to start logging everything on the Flash side to see where the breakage is.
Since you're using IE, I recommend getting the Debug flash player, installing it, then running Vizzy along side to show your traces.
Should give you a good idea of where the app is breaking down.
Vizzy
Debug Player

Phonegap 3 contains an alert box in which "OK" crashes browser

I can't come up with a good explanation for this, but when I include
<script type="text/javascript" src="phonegap.js"></script>
In my Phonegap app, which I have not modified, 2 pops will appear on screen.
//The first popup
gap:["PluginManager","startup","PluginManager224542697"]
//the second
gap:["App","show","App224542698"]
I have to cancel both popups and would really love to understand the reasoning.
The two lines in question are on line 21117 and 21118 of phonegap.js
// Tell the native code that a page change has occurred.
require('cordova/exec')(null, null, 'PluginManager', 'startup', []);
require('cordova/channel').onNativeReady.fire();
This of course does not break when its in the app, but it does mean that development is next to impossible.

For me the issue was occurring because phonegap.js was falling back to PROMPT based mode when running outside of phonegap. I believe this mode is intended for phonegap below Android 3.2, where all communication is via alert prompts (which is what you're seeing).
I fixed the problem by setting the following variable before loading phonegap.js:
window._cordovaNative = true;
This tricks phonegap into thinking you're running above phonegap 3.2 hence never enters Prompt mode.
Of course, if you're targeting devices below 3.2 then doing this will probably break all communication with Phonegap on those devices...

I have stumbled upon this error and question while trying the following:
Completed the hello world tutorial with cordova create, etc.
Deployed both on emulator and the connected device w/o a problem.
I got the same error as OP when doing cordova serve and just navigating to //localhost:8000 as instructed.
I agree - seeing those alerts is super annoying. It kills the whole point of speedy non-native js-based development.
What is going wrong?
Communication API with the "device" is falling back to this handler promptbasednativeapi.js (also see cordova-js/src/android/exec.js). On version 3.x.x just saying
window._cordovaNative = true;
was not enough for me. One should implement the whole protocol of communication.
Quick solution
You can use some browser side "emulator", e.g. Ripple emulator extension for chrome ([UPDATE] Consider using https://github.com/apache/incubator-ripple for phonegap 3.x.x as pointed by DuKes0mE). Such an "emulator" can understand and fire respective events, e.g. "device ready". So far it looks promising :-)
What is going on?
An answer by #antscode was of great help. After some digging and reading of cordova/cordova-js code I figured out that
Error comes from the mechanism which is a part of cordova plugin architecture. Plugins are developed as so called cordova commands which can be executed from js - this is exactly how cordova architecture is organized.
Cordova is a JS framework. One is suggested to primary write (non-native) JS code. To talk to all those different native plugins one has to come up with the protocol to communicate with them, sort of RPC with JSON serialization. This is exactly what is going own.
Plugins can be also in pure JS. To quote the manual
Create a new echome plugin with:
window.echo = function(str, callback) {
cordova.exec(callback, function(err) {
callback('Nothing to echo.');
}, "Echo", "echo", [str]);
};
Access it as a cordova command via JS:
window.echo("echome", function(echoValue) {
alert(echoValue == "echome"); // should alert true.
});
No emulator solution
I could imagine a situation when an rather complicated app will break just inside such an web-browser client side "emulator" (and only in it). A better solution would be to figure out a way to convince the app not to fallback to PROMPT method of communication (the one that makes annoying alerts). Well, I do not have such a solution right now :-( Will be happy to learn how to do it though.
Solution is here: https://gist.github.com/ewiger/7d5e0cc8fccf311e9ce2

there is probably no return event for the cancel button. if no instructions are passed to the kernel, this results in an exception(your browser crashing.) try defining an action for the cancel button and see if that helps.

I went into hello/platforms/ios/CordovaLib and copied the cordova.js file into my www root and changed
Or download from here:https://github.com/apache/cordova-ios/blob/master/CordovaLib/cordova.js
<script type="text/javascript" src="phonegap.js"></script>
to
<script type="text/javascript" src="cordova.js"></script>
and no more popups

I was having the same issue with a project created by another developer. The cause in my case was the remains of the Cordova/PhoneGap 2.x configuration. This popup is related to the plugin system. Removing plugin from my config.xml made it better:
<plugin name="InAppBrowser" value="org.apache.cordova.InAppBrowser" />
The end, I decided it would be best to make a new 3.x project and move all of my HTML/CSS/JS to the newly created project. The new project fixed all issues.

I had initially resisted posting an answer on this question. As was mentioned by one of the developers that the phonegap.js should not be included unless it is production code.
This however means you can't tests phonegap features.
To briefly explain my thought process, in all my years developing (php) I have often set global variables that I can easily write code for dev, stage or production.
Please consider this might not be the best way to go, but for me it works and I'm enjoying the rest of my backbone app far more than revisiting this currently ;)
So, I did this:
//Define SD
var SD = {}; //define SD so we can use it globally
/*==================================================
Is Mobile - If true then we are a mobile
================================================== */
SD.isMobile = true;
//This is with the assumtion that your domain contains (for exmaple) http://yourdomain.local
if (document.URL.indexOf("local") > 0 || document.URL.indexOf("sex") > 0) {
SD.isMobile = false;
}
SD = {
isMobile: SD.isMobile,
ENVIROMENT: 'liveApp',
CDN: 'yoururl.com/',
HTTP: 'http://yoururl.com/',
}
// #define the globals depending on where we are -----------------------------------------------------
SD.globals = function () {
switch (window.location.hostname) {
case "sd.local":
SD.ENVIROMENT = 'localApp',
SD.CDN = 'sd.local/',
SD.HTTP = 'http://yoururl.com/',
SD.AJAX = SD.HTTP+'app/';
break;
case "192.168.0.25": //Set to your machines IP address
SD.ENVIROMENT = 'mobilePhone',
SD.AJAX = SD.HTTP+ 'app/';
break;
default:
SD.AJAX = SD.HTTP+'app/';
break;
}
};
And now finally, after all the init work I add the phonegap.js if we need it.
if(SD.isMobile){
$.getScript('phonegap.js', function( data, textStatus, jqxhr){
c( "cordova was loaded." );
});

I was experiencing the exact same two popups you describe but only experienced them when i added iOS to my phonegap project. the first time i did this i copied the www folder from my working Android app. this was the problem because it had artifacts from the Android plugins. After blasting and recreating the iOS app in the phonegap project using the command line tools i more carefully brought over only the needed html, js and css files for my app which resolved the issue.

Firefox ChromeWorker not loading script

I have a requirement where I need to communicate with native code to perform some operations. I have been successful by using JS-Ctypes and things are panning out as expected. Since the communication from my web application with the native code takes some time, thus blocking the main JS thread consequently freezing the UI.
Thus I need to create a separate thread to be delegated with the communication with the native code and post back results to the main thread which will give the appropriate feedback to the user. Firefox ChromeWorker are exactly what I need to use, since they are independent threads with access to JS-Ctypes.
My problem is that for the life of me, I can't seem to load a script using that approach. This is what I currently have:
main.js
netscape.security.PrivilegeManager.enablePrivilege('UniversalXPConnect');
Components.utils.import("resource://gre/modules/Services.jsm");
var worker = new ChromeWorker("js/fpman/myworker.js");
worker.onmessage = function(e){
console.log(e.data);
};
worker.postMessage('start');
myworker.js
self.onmessage = function(e){
var sum = 1 + 1;
postMessage("Sum is " + sum);
};
When that code runs in the main JS, I get this error on firebug console
Failed to load script: http://localhost:8080/myapp/js/fpman/myworker.js (nsresult = 0x805303f4)
Point to note, when I use a normal worker thread i.e
var worker = new Worker("js/fpman/myworker.js");
the js file (myworker.js) is loaded fine and I get the expected result, but of course that doesn't suffice my needs since a normal worker doesn't have access to JS-Ctypes. So it seems the problem is how am creating the ChromeWorker. Could someone please enlighten me on how to appropriately instantiate and use the ChromeWorker Object from an application. I have seen a lot of reference of usage of ChromeWorker in extensions, but that is not what I want, I want to use the ChromeWorker in my web application.
Thanks.

That particular error is NS_ERROR_DOM_BAD_URI
I don't believe what you are doing will work, and I know it won't work very soon in Firefox because enablePrivilege is going away completely.

Using the same codebase for phonegap and web?

Is it wise to use the same codebase for our mobile web app and phonegap app? They are meant to be similar, the phonegap version just lets us do more. Can we detect if it's not running on phonegap and sequester calls to the phonegap api or does it make more sense to separate them.

Sure, you can use most of the same codebase.
Some phonegap APIs are the same in html5 (for instance localStorage) so there's no difference in code there.
If you're using phonegap Build service, it will add the phonegap.js / cordova.js script file to your project root. Just include it in your html all the time. Then you can detect whether your application is running within phonegap:
var isPhonegap = function() {
return (typeof(cordova) !== 'undefined' || typeof(phonegap) !== 'undefined');
}
if (isPhonegap()) {
// phonegap.js/cordova.js exists.. now let's handle the onDeviceReady event
} else {
// in-browser
}
If you need some common startup code, put it in a function and call this function from the onDeviceReady handler and the else block above.
If the phonegap api you're calling doesn't have the exact same name as the html5 one (because it has the Moz* or WebKit* prefix for instance), just wrap both inside a new name. For instance:
var requestFileSystem = (isPhonegap() ? requestFileSystem : window.WebKitRequestFileSystem);
If the phonegap API you're using really has no html5 equivalent, try to duplicate the functionality yourself in javascript if possible, otherwise you'll just lose the functionality in your browser. But make sure it degrades gracefully enough without that feature.
Note: to test the mobile devices features like accelerometer, geolocation, etc.. in your browser checkout the Ripple Chrome extension.

I figured out a way to keep the web codebase intact...
The current problem with using the built in deviceready event, is that when the page is loaded, you have no way of telling the app: "Hey this is NOT running on an mobile device, there's no need to wait for the device to be ready to start".
In the native portion of the code, for example for iOS, in MainViewController.m there's a method viewDidLoad, I am sending a javascript variable that I later check for in the web code, if that variable is around, I will wait to start the code for my page until everything is ready (for example, navigator geolocation)
Under MainViewController.m:
- (void) viewDidLoad
{
[super viewDidLoad];
NSString* jsString = [NSString stringWithFormat:#"isAppNative = true;"];
[self.webView stringByEvaluatingJavaScriptFromString:jsString];
}
index.html the code goes like this:
function onBodyLoad()
{
document.addEventListener("deviceready", onDeviceReady, false);
}
function onDeviceReady(){;
myApp.run();
}
try{
if(isAppNative!=undefined);
}catch(err){
$(document).ready(function(){
myApp.run();
});
}

I would use the same codebase. The whole point of PhoneGap is to convert your mobile sites into apps. It isn't that difficult to detect features and screen realestate as appropriate. The trouble with seperate codebases is usually the cost of double-handling your content and styles. If necessary you could separate those out into a shared resource and bundle them at runtime/access but personally I'd still go with keeping it all together.
This blog covers the detection issue (see the comments too): http://bennolan.com/2011/08/22/phonegap-detection.html. The crux of it though is if (window.PhoneGap){...}

Connect Firefox extension with C# application

I need to be able to make an event such that every time a user loads a new page and closes firefox, I need it to call a method in my C# application that takes care of maintaining the user model. I know for sure I need to create some type of firefox extension where I use javascript to check such an event. However, I have no idea how I am going to integrate my C# application with the firefox extension. Can someone provide me with some guidance?

I'll help you out with the parts of the question that I'm familiar with (Javascript based add-ons), and offer some suggestions for the other parts. Here goes nothing!
Add-ons
Firefox add-ons easily provide the tools you need to detect page loads and opening / closing firefox.
To detect page loads you can register a listener to the DOMContentLoaded event in window.
window.addEventListener("DOMContentLoaded", function(event){
var url = event.originalTarget.location.href;
alert("Oh yeah, a document is loading: " + url);
}, false);
Alternatively, you can register a nsIWebProgressListener to listen for location changes. This probably closer to what you want, since DOMContentLoaded is also triggered for iframes.
var listener = {
//unimplemented methods (just give functions which do nothing)
onLocationChange: function(aWebProgress, aRequest, aLocation){
var url = aLocation.asciiSpec;
alert("Oh yeah, a the location changed: " + url);
}
};
gBrowser.addTabsProgressListener(listener);
To detect firefox open / close you need to first understand how firefox add-ons work with respect to multiple windows. When a new window of firefox is launched, you basically have 2 separate copies of your code running. So, if you care about firefox windows being opened and closed you can simply do:
window.addEventListener("load", function(event){
alert("Looks like you just opened up a new window");
}, false);
window.addEventListener("unload", function(event){
alert("Awh, you closed a window");
}, false);
But, most likely you want to detect opening / closing firefox as an entire application. This is achieved using a code-sharing mechanism called Javascript Modules. Javascript modules are loaded just once for the lifetime of the application. So, they enable you to share information between windows. Simply counting the number of windows opened and closed should be sufficient for this functionality.
var EXPORTED_SYMBOLS = ["windowOpened", "windowClosed"];
var windowsOpened = 0;
function windowOpened(){
if( windowsOpened === 0) {
alert("The first window has been opened!");
}
windowsOpened++;
}
function windowClosed(){
windowsOpened++;
if( windowsOpened === 0) {
alert("The last window has been closed!");
}
}
Then you can simply attach the aforementioned event handlers to call these 2 methods from their corresponding load and unload events.
So, this is all great and everything, but now you have to twiddle with the details of getting a baseline Firefox add-on setup. Fortunately, Mozilla has provided a handy Addon Builder to ease this. All the code about (except the Javascript module) should be placed in the ff-overlay.js file (assuming you use the linked builder).
C# communication
I'm a little less knowledgeable about the interprocess communication with C#. However, maybe I can point you in the right direction and let the smart people at SO fill in the rest.
I believe COM Objects are a method of communication between processes on Windows. So, you could build in a Binary Component to your add-on to perform the communication. However, as far as I understand it, setting up binary components is much more difficult than a standard javascript-based add-on. Either way, Mozilla provides a guide for setting it up in Visual Studio.
If you want to stay away from binary components you are left with the javascript enabled components of the SDK. This includes socket communication, files, pipes, a sqlite database etc. This SO question addresses exactly the question you're asking. If it were me, I would choose them in this order.
Sqlite Database
Named Pipes
Sockets
(1) because there is a lot of code samples available for this, and would be easy to implement on both sides. (2) because this would be the way I'd implement IPC if I were given full control of both sides of the application. (3) is last because I hate that crap (maybe I'm biased from Distributed Systems in college).
tl;dr
The page load stuff should be pretty simple. Check out the Addon Builder to get going with a FF addon, and here to see about detecting page loads.
The C# communication is doable, and addressed in this SO Question. I'd do it with a sqlite database for ease if it were me.