Develop Reference

Can Swift Scripts Execute in a Swift iOS App?

We have an iOS app (Obj-C) that grabs a JavaScript file from AWS S3 to run our proprietary algorithm on a bunch of raw image data right on the iPhone (Lambda functions produced some latency I guess). For the sake of security, the JavaScript is obfuscated and entirely unreadable, and even harder to debug.
Well, the JavaScript is spitting out NaN result values back to the iPhone, and I am seriously struggling to even find where this NaN pollution starts. Very frustrating.
Behind the scenes I am working on refactoring this entire project to leverage Swift instead. It's much easier to dev/maintain than Objective-C (IMHO). Also, Swift can be used for scripting, so I'm thinking I can just reduce my tech stack by removing the JavaScript entirely.
Question: Can a Swift script execute in a Swift iPhone app the same way JavaScript can? If yes, how?
The Objective-C code snippet (modified for brevity)
functionCall = [NSString stringWithFormat: #"some JS function call"];
[jsContext evaluateScript: functionCall];
JSValue* jsv = [jsContext objectForKeyedSubscript: #"result"];
NSDictionary* result = [jsv toDictionary];
// result is != nil, but the values are all NaN
// Can't find the error when debugging JavaScript in Chrome
// C# utility app that does the same thing produces good results
I am aware that Apple will reject an app for the App Store if using an obfuscation tool on the source code is detected, or I'd consider purchasing a license for one. Also, we have an identical Android app, so if I can do the same with Kotlin scripts then I'll be a happy camper.
Another concern I have is if the obfuscated JavaScript code is even increasing the security. I understand that a jailbroken device can access device memory and get a hold of code at runtime, which makes me think I'm performing an exercise in futility. Phrased differently, is the obfuscated JavaScript effectively more secure than manually/primitively obfuscated Swift source code?

As user jvnpdx stated, it is not possible to dynamically run a Swift script within the app.

How to debug javascript with Eclipse running local Tomcat server

There are a lot of questions on SO about how to debug a standalone piece of Javascript - that isn't what I want. None of the previous Eclipse/javascript questions seem to be on point, which surprised me.
I am using Eclipse for Java EE (Neon, the latest version) to develop a JSP/servlet website - a full website, not just javascript, and not just java/jsp - everything together. I can compile my Java and "debug as" on an instance of Tomcat spawned by Eclipse, and the web pages show up inside of a window in Eclipse. I can set and hit Java breakpoints all day long while using "debug as" - but setting breakpoints in javascript doesn't do diddly squat. I've been having to run a standalone instance of Tomcat, deploy war files to it, wait for the war files to decompress, then debug my Javascript inside of Firefox. This is particularly annoying because I'm relatively new to javascript and am doing some complex things on the page (and truth be told, making some silly mistakes a compiler in a typed language would catch for me before letting me waste my time trying to run the code) and the "change, watch Eclipse chew deploying war, wait for Tomcat to chew uncompressing the war, test" cycle is just unacceptably long.
Isn't there an easier way to debug BOTH java and javascript from the same IDE without having to export and deploy WAR files? Is there is a setting I can toggle or something I can install in Eclipse to make it an all-in-one IDE? Ideally I would like to be able to step through, for example, an AJAX call into my servlet AND watch what happens in the javascript after it returns - within the same debugging session - so let me preemptively state that copying the changed js file(s) directly to the decompressed folder in tomcat/webapps as a faster way to continue to do split debugging is not the kind of "workaround answer" I'm looking for.

JavaScript debugging is going to be supported in Eclipse Neon 1 release (September 2016). Here is a demo video in which step-by-step process of debugging both front-end and back-end is explained - https://youtu.be/7oQz1Ja1H08 .
Basically, running Chrome / Chromium with extra parameters and tuning source mapping manually is not really user-friendly now, but we are going to improve it for Neon 1 and future releases.
Contributions of any kind are most welcome ;)

Working with Javascript and Xcode

I'm experiencing a less-than-ideal workflow at the moment. Here's the context:
The project is a hybrid native-web application
The javascript files are either local (in a .bundle) or on a http server
We have a lot of javascript tests, most of which are integration tests and must be ran in the simulator.
Although I love javascript and the idea of a reusable application, I must recognize that Xcode doesn't play fair. The main pain is that, quite often and despite the full clean / simu reset, Xcode will need to compile twice before it takes the javascript changes in account.
I've tried to touch all the javascript files before each build (as a script run build phase).
I've also tried to clear the webview cache before each run:
[[NSURLCache sharedURLCache] removeAllCachedResponses];
None of the two suffice.
tl; dr: What is your workflow when working with javascript files inside an Xcode project, do you like it and how could I improve mine?

How does GWT Plugin work?

It is documented that GWT converts java code ( a few extensions not supported ) to javascript which gets rendered. When does this conversion happen? I want to know the steps and the agents involved at each step.
Why do we need GWT plugins for each browser? What part of the conversion is handled by the library and what part is handled by the plugin?
I have read a lot of tutorials but this point is still vague.

It is important to understand about GWT that there's a big difference between production mode and development mode. You write Java code and for deployment, the GWT compiler compiles it to JavaScript which is then interpreted by the browser. So, in production, the conversion happens only one time, before you deploy your web app to a server. And in this case, no browser plugin is needed because modern browsers can interpret JavaScript without any help.
In development mode however, things are different. The Java code is interpreted by the GWT browser plugin directly, without an explicit compilation from Java into JavaScript. So you only need a browser plugin in development mode.
And then there's super dev mode, which is different from the scenarios above.
This page explains it all.

Developing Windows apps with JavaScript

I'm currently in the need of developing a Windows application. I want to keep things simple (in the spirit of uTorrent) and I would like the result program to be a single .exe file containing all that it needs.
The program is simple. It just needs some UI. It needs to run for a long period of time (lay there as a tray icon). It needs to do some routine tasks like simple I/O. It also needs to access the internet, specifically some web server.
Apart from these small requirements I would like to write all of it in JavaScript, as I feel more comfortable with it than any other language.
I know there's things like Windows Script Host that let you run JavaScript programs and interact with some Win32 API, but will I be able to do everything I need with Windows Script Host? Can I pack all of the Windows Script Host in a single .exe?
If not, what alternatives do I have for JavaScript?

I found that there's actually a JavaScript compiler that comes with the .NET framework called jsc.exe.
For more information:
http://www.phpied.com/make-your-javascript-a-windows-exe/
http://msdn.microsoft.com/en-us/library/7435xtz6(VS.80).aspx
I guess it's not really JavaScript since it introduces extra things like import and even some class syntax which is weird for me. But this works perfectly for me as I will just doing things as I am used to on the web.

Aside from Windows Script Host, there are
Windows Desktop Gadgets (Vista and Windows 7 only)
HTML Applications (HTAs)
Both are written with standard web technologies, HTML, JavaScript, Flash, etc. They can also be extended with COM objects/ActiveX controls such as FileSystemObject, WMI, WScript or even ones that you write yourself. Windows Desktop Gadgets have access to a separate API/namespace with various Win32-esque properties and methods.

It seems that nobody mentioned JSDB.
JSDB offers a command line environment which you can execute arbitrary javascript code. You can easily compile to a .exe file by using the command copy /b jsdb.exe+program.zip program.exe
It's important to know that you've got to call your main js file main.js within a standard zip file. Not sure if the name program.zip is required.
I haven't actually tried making GUI applications with this yet - although it seems to support various APIs like ActiveX.
It's possible that by using the copy /b command mentioned above, you could compile a script from the wscript.exe file - but I tried and couldn't get it working. Let me know if anybody tries and has success somehow.

I think you're looking for Adobe AIR
The Adobe® AIR® 2 runtime enables developers to use HTML, JavaScript, Adobe Flash® software, and ActionScript® to build web applications that run as standalone client applications without the constraints of a browser. ~ The AIR website

Internet Explorer introduced the concept of Hypertext Applications in IE 5. It never made a big breakthrough, so resources and documentation are scarce.
Mozilla-backed competitor Prism seems to be alive and well, though, and is definitely worth a look.
Prism is an application that lets users split web applications
out of their browser and run them directly on their desktop

I believe the best way to go is V8 JavaScript Engine provided by Google.
"V8 can run standalone, or can be embedded into any C++ application." - which I believe is perfect for your needs, because you can do most of the stuff in JavaScript and use provided interfaces to communicate with the system.

I'm not 100% but I believe WSH uses JScript or WScript, not JavaScript.

Color me crazy, but its only a short step form Javascript to Java or C#. I'd suggest C# as, on a windows machine, the libraries are already there. You can just copypaste your .exe and let 'er rip.

If you want a single .EXE, what runtimes are you okay if they are required pre-requisites?
If you're okay with requiring .NET runtime to be preinstalled, then you do all your work in JScript.NET

Chromium Embedded Framework (CEF) may give you some help. i have not clearly know how, but i realy found many Apps using this framework.
http://code.google.com/p/chromiumembedded/
Introduce for CEF are:
The Chromium Embedded Framework (CEF) is an open source project founded by Marshall Greenblatt in 2008 to develop a Web browser control based on the Google Chromium project. CEF currently supports a range of programming languages and operating systems and can be easily integrated into both new and existing applications. It was designed from the ground up with both performance and ease of use in mind. The base framework includes C and C++ programming interfaces exposed via native libraries that insulate the host application from Chromium and WebKit implementation details. It provides close integration between the browser control and the host application including support for custom plugins, protocols, JavaScript objects and JavaScript extensions. The host application can optionally control resource loading, navigation, context menus, printing and more, while taking advantage of the same performance and HTML5 technologies available in the Google Chrome Web browser.
Numerous individuals and organizations contribute time and resources to support CEF development, but more involvement from the community is always welcome. This includes support for both the core CEF project and external projects that integrate CEF with additional programming languages and frameworks (see the "External Projects" section below).

Why not use Rhino -- JavaScript on the JVM? You can even compile your scripts to .class files and package them into a JAR along with Rhino for easy distribution...