The Short
I am trying to create a List<ScanFilter> in JavaScript by accessing Android API, as shown below:
var scanFilterList = new java.util.List<android.bluetooth.le.ScanFilter>;
However, JavaScript gives me a SyntaxError due to an unexpected token, which I presume is because of the angle brackets. Any assistance in overcoming this problem and creating a List<ScanFilter> would be greatly appreciated!!
The Long
I want to periodically run BluetoothLE scans in my NativeScript application (only worrying about the android side for the moment), even while the screen is turned off. To my understanding this would be possible, as stated in the documentation:
For unfiltered scans, scanning is stopped on screen off to save power. Scanning is resumed when screen is turned on again. To avoid this, do filtered scanning by using proper ScanFilter.
Source
I am attempting to create a ScanFilter to be used as a parameter for startScan() when it is called. However, when I try to create a new List as shown below:
var scanFilterList = new java.util.List<android.bluetooth.le.ScanFilter>;
I get a SyntaxError due to an unexpected token. I am assuming this is because the angle-brackets aren't recognized by JavaScript and cause problems.
How can I bypass this problem and successfully create a List<ScanFilter> variable in JavaScript for use.
Related
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
I am using the FriendBuy app for a shopify store at this moment and am running into an issue where an illegal token is being caught, aside from that there are no other issues that I can see. What I am trying to do is activate the referral via a text link. I have followed the documentation according to the app to the letter, but after running a javascript validation test on the code a number of errors popped up. I find it hard to believe an expensive app with a huge user base would fail on something simple so the issue must be on my end but I can't seem to discover where. The code creating the issue is
window['friendbuy'].push(['widget', ‘xx-xxx’, {configuration: {share_button:false}}]);
according to the documentation this is what i should use, replacing xxx-xxx with the campaign id. The only inconsistency I can see is that the suggested x's to fill are 5 characters long, where the actual code is 6, but that is what I came up with after following the documentation.
It looks like your javascript has Microsoft quotes around the ‘xx-xxx’. If you change them to 'xx-xxx' it should work.
Corrected example below:
window['friendbuy'].push(['widget', 'xx-xxx', {configuration: {share_button:false}}]);
I have javascript error tracking on my website. Recently I started getting the following error from Chrome (versions 37 and 38) on iPhone (IOS 7 and 8):
ReferenceError: Can't find variable: __gCrWeb
I couldn't find any useful information about this error except for a few references. Has anyone seen it before and knows why it happens?
__gcrweb is a reference by gcrweb.js, which is a local (on device) js getting injected by the iOS version of Chrome.
Google needs to do this for some extended functionality (mostly inserting/retrieving login credentials and other form information you stored via another synced Chrome browser) which isn't provided by the native webview it's built on and can't be added to it otherwise.
This should not affect any parts of your code and i'd get rid of it by ignoring it in your error logging (the error should always be the same string), for example:
https://docs.sentry.io/clients/javascript/config/
https://rollbar.com/docs/notifier/rollbar.js/#ignoring-specific-exception-messages
Another solution could be to make sure that the reference always exists by declaring it yourself at the beginning of your js init
if (!window.__gCrWeb) window['__gCrWeb'] = {};
just like Google does it.
I am trying to over ride one the notification popups of browser using the following code:
var branch = Components.classes["#mozilla.org/preferences-service;1"].getService(Components.interfaces.nsIPrefBranch);
But in Mozilla Firefox, I get the error Component.classes is undefined.
And in Chrome Browser, I get the error Component is undefined.
Well I have realised I need to include something in my website. But I am unable to find exactly what is required.
Please anybody help. I googled about it a lot, but I have never used this thing before(the Classes) and I am unable to search what will help me out. i dont even have any idea that what will be the tags for this thing. I have never used Component or its classes
My website is in ZF2.
Components Object is non-standard feature. See https://developer.mozilla.org/en/docs/Components_object.
It also says
Warning: This object is only intended for code running with chrome
privileges. Exposing the object to regular web code was a mistake.
I am currently working on a calculator that will run as a packaged (desktop) chrome app. I am using the math.js library to parse math input. This is my old code:
evaluate.js:
var parser = math.parser();
function evaluate(input){
$("#output").text(parser.eval(input));
}
However, if the input is something unreasonable like 6234523412368492857483928!, the app just freezes, because it is trying to evaluate the input. I know that math.js is still in beta so eventually there might be a fix (overflow errors), but I couldn't find any other library that parses raw input the way math.js does.
To fix this, I am trying to fix this using web workers to run it asynchronously. Here is the code that I have right now:
main.js
var evaluator = new Worker('evaluate.js');
evaluator.addEventListener('message', function(e){
$("#output").text(e.data);
}, false);
function evaluate(input){
evaluator.postMessage(input);
}
evaluate.js
var parser = math.parser();
function mathEval(input){
return parser.eval(input);
}
self.addEventListener('message', function(e){
self.postMessage(mathEval(e.data));
});
However, this doesn't work when I run it. Also, I noticed that when I use web workers, it throws the error Uncaught ReferenceError: math is not defined - evaluate.js:1, but it didn't throw this error with the old code.
Questions: Why doesn't this code work to evaluate the input? Is it possible to use multiple workers to speed it up? If I wanted to implement some sort of overflow error for when the worker takes more than 2 seconds, what would be the best way to go about doing it? Finally, is there a better way to do this?
Web Workers are run in totally separate context. They don't have access to the objects from parent web page. If you want to use math.js you have to import it into the worker using importScript.
I recommend to read Using Web Workers guide, part "Importing Scripts And Libraries" which describes how to do it, and how it works in detail.