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I'm working on a portfolio website, and I thought it would be cool to be able to run my scripts in python, java, js, rust, etc locally in the browser
Here's an example of this from w3schools
I'm guessing they have a translation layer to javascript, but in the event that they're actually running C++ here, does anyone know how this might be done or generalized?
They do not translate those languages to JavaScript and then run it on the client - that would be a herculean task to get right, especially for multiple languages. Rather, they (and the many similar sites like try it online) take the source code text from the client's browser, and run it on the server, and respond to the client with the result from the server.
To achieve something like this, you'd need
A backend (in any language)
Compilers/interpreters/etc for all languages you want to support
A way for the backend to programatically call them with the user's input (which is often pretty easy)
For proof that w3schools takes the result from a server, rather than running it locally, examine the network tab of your browser, and you'll see it:
This is more of a curiosity really, to see if some one has done anything similar, or if at all it is possible.
I'm working on a project that will get notification through external notifications. Now I could go about doing this by having notifications coming to my server and have a comet setup between my client and server.
BUT
I was wondering if I could write server logic into my client and listen out for notifications from external sources. Immediately one issue I see is, external sources would need callback URL etc, which I dont know if you could do from client side (unless one could use the IP address in that way).
As you can see it is more ideas and discussions if such a thing was possible, this is somewhat inspired by P2P models whereby you wouldn't be mediating things through your central server.
Thanks in advance!
GWT compiles (nearly) Java source into JavaScript, so compiled GWT apps can't do anything that traditional JavaScript running in the browser cannot do. The major advantage of bringing Java into the picture isn't automatic access to any/all JVM classes, but the ability to not only maintain Java sources, which tend to be easier to refactor and test as well as keep consistent with the server, and to compile that statically defined code into JavaScript, performing all kinds of optimizations at compile time that aren't possible for normal JavaScript.
So no, while you can have some code shared by the client (in a browser) and the server (running in a JVM), you can't run Tomcat/Jetty/etc in the browser just by using GWT to compile the java code into JS.
As you point out, even if this was possible, it would be difficult to get different clients to talk back and forth, without also requiring that the browsers can see and connect at will to one another. BitTorrent and Skype have different ways for facilitating this, and currently browsers do not allow anything like this - they are designed to make connections to other servers, not to allow connections to be made to them.
Push notifications from the web server to the browser are probably the best way forward, either through wrapping comet or the like, or through an existing GWT library like Atmosphere (see https://github.com/Atmosphere/atmosphere/tree/master/samples/gwt-demo for a demo).
When I say "Vanilla Coding", I am referring to websites that don't utilize server side coding (such as PHP, ASP, etc.), only HTML, JavaScript, and CSS.
I know that there are a plethora of sites that already exist that don't utilize (to my knowledge) any of the common, server side languages used by many others (PHP, ASP, etc.), but still function just fine!
I am confused! How do these sites continue to save login information, keep records, etc. etc. without using a server side scripting language? Is there something that I am missing? Can JavaScript access more (such as databases and local files) than what I thought it could?
EDIT
Turns out I've made a serious and shameful mistake in assuming that just because it ended with a .html extension that it was client-side only. That is okay though because I'm learning. Thanks so much for the help everybody!
Essentially, unless you have some sort of server-side programming, you don't stand a chance at making a site with any amount of functionality. To break it down for you:
What you can do without server-side scripting:
Serve static pages
What you need server-side scripting for:
Absolutely everything else
Even something so simple as keeping a site consistent and up to date is a nightmare on wheels without, at the very least, some some sort of management system that pre-generates the static pages to be served. (Technically, one could argue that Copy+Paste in Notepad counts as this.)
As has been mentioned elsewhere; obfuscating the true nature of precisely what system is being used is trivial; and having URLs ending in, say, .html while using PHP is no issue.
Edit: In the most perverse case I can think of off the top of my head, you could have a lighttpd server masquerading as an IIS server, serving pages generated by an offline renderer fed to it by a Perl FastCGI script, sent together with PHP signature heading and using a mix of .asp and .jsp file extensions.
Of course, noone would do something as silly as that. I think…
No client side script can access server side information (like a database) without some sort of server side communication (through something like ajax or the like)
If you really ( i mean really as in don't do it ) want to do logins and the like on clients side, you would have to make some sort of cookie that you store on the user's computer, also you would need a list of users (which anyone can read) to use against
This answer is very late but I leave this reply for anyone who may stumble upon it.
Using javascript/jQuery, and various APIs a simple site can be created only using client-side coding.
For instance, a simple shopping cart type of site can be created. I've done it before.
There are few (not many) strictly 100% jQuery based shopping cart solutions that are open-source.
How does the PG (pay gateway) get taken care of? You are limited to accepting payment through paypal, google checkout, and direct deposit.
What about allowing customers to leave comment? You can use API's like Disqus. What about chat support? Zopim is pretty handy.
How do you get notified when purchase is made? Paypal & google checkout notifies you.
What about sending mass email? Mail Chimp.
Personally, I almost always use WordPress or some other types of CMS but using only vanilla coding to build a simple site is not only feasible but very sensible in certain circumstances.
You're not going to see whether a site is using a server side language unless they let you see the file extensions. With URL rewriting, MVC patterns, etc., it's easy to hide, or even fake that information. Therefore, chances are very good that the sites that you think aren't using a server side language are actually using one.
Now, a site can save certain information in cookies, such as some basic preferences, but any authentication they appear to be doing wouldn't actually be doing anything without a server-side script accessing a database somewhere.
As a side note - I have worked on a site where the content was actually static, but made to look like a blog or CMS. It was an absolute nightmare and hugely error-prone.
What are these sites that you think aren't using server-side scripting?
Nowadays a lot of sites are using Javascript as a server side solution, Node.js being the most popular. Check out this list: https://github.com/joyent/node/wiki/Projects,-Applications,-and-Companies-Using-Node
I'm now thinking to establish my server-side code in JavaScript, and begin to do all on it, but I want to know about its security and flexibility compared to PHP.
I want to know too, if it can be successfully used to develop things like forum boards, full web-sites and things like this, as PHP does.
Javascript is just now starting to get some presence on the server, with things like ServerJS and nodeJS, but right now, you would probably be best off using PHP for your server side code, and javascript for client-side beautification.
The question is very, very broad. Interpreting it as "can I use Javascript on the server":
Fundamentally, sure, Javascript is a very powerful language and so you can do development in it server-side just like you can client-side (and if you do client-side scripting as well, you get some definite reuse benefits using Javascript on the server).
For Apache systems, there's the v8cgi project (a FastCGI Javascript plug-in with connectors, using Google's freaky-fast V8 engine).
On Microsoft-based systems, IIS supports Javascript (JScript) on the server out of the box (I use that all the time), which has access to all of the ActiveX stuff (e.g., for talking to databases, dealing with the file system, etc.).
If your server framework is JVM-based, there's Rhino, which is Javascript for the Java platform and has access to all (or nearly all) of the libraries available for Java — e.g., a huge ecosystem of libraries and plug-ins.
Aside from v8cgi, there are a couple of other projects built on Google's V8 engine.
There's a place that does a full stack for you called chromeserver (I don't know what their backend is; I'm not going to infer from the name).
Paul mentioned ServerJS and NodeJS.
There's the whole CommonJS project.
Etc. etc. etc. There's quite a list on Wikipedia.
Arguing against, there's a very rich ecosystem built around PHP. Unless you're using something like Rhino for the Java platform or JScript on IIS (because of the ecosystems they leverage), you may find that you don't have nearly that ecosystem available to you when developing in Javascript for the server. I mean, if you're looking for pre-built forum or wiki software (for example), let's just say you can't swing a dead cat without finding one based on PHP, and the same cannot be said of Javascript on the server.
The way they are usually used, PHP and JavaScript run in entirely different worlds, and are not really comparable. (There is a server-side version of JavaScript but it's fair to say it's not especially widespread yet, and doesn't run on standard web hosting.)
The security issues you are going to encounter in JavaScript (on the browser) side are very different from what you have to look out for in PHP.
I want to know too, if it can be sucessfully used to develop things like forum boards, full web-sites and things like this, as PHP does.
No, not with client-side Javascript. For dynamic applications, you will always need some server-side language backing it, be it PHP or some other language like ASP, Python, Ruby, Perl....
To replace PHP with Javascript, you need server-side Javascript and there is a lot happening on that front. Mozilla’s Rhino runs Javascript atop the JVM and it seems Google is also working on its own server side Javascript framework. The most popular in-production implementations are:
Helma: Several active projects are using it, runs on Jetty & Rhino and lets developers leverage the power of JVM, has its own object-oriented MVC framework
Project Phobos: runs on Glassfish & Rhino and lets developers leverage the power of JVM, includes plug-ins for NetBeans and integrates with jMaki Web UI framework
JSSP: A very simple server side framework, a lot like classic ASP, JSP and PHP
Aptana’s Jaxer showed a lot of promise, especially by bringing the DOM to the server side, but the project seems dead now. From what I understand, node.js is not a server-side Javascript framework in the same sense as Helma and Phobos. Instead it can be used for writing event-driven servers in Javascript (for example: writing your own web server).
Yes, my site is written by node.js
Using websvr, it's Java style have filter and handlers, hosting on debian OS.
This is slightly off-topic, but it may actually get to the core of your question:
if you want to use only one language for web applications, you may wanna have a look at Haxe.
It is a cross-platform language, that (among other targets) compiles to JavaScript and PHP source as well as NekoVM bytecode. For server-side JavaScript, there are NodeJS bindings.
This way you are not bound to a specific platform. The neko and PHP APIs are largely compatible, so you can deploy on both platforms, having the option to choose neko's speed and persistency or PHP's ease of deployment. Please note however, the PHP output has a little overhead although common optimizers as eaccelerator will make this barely noticeable.
Haxe is significantly less forgiving than both JavaScript and PHP. This makes it harder to learn, but a much safer, robust and in the end more productive tool.
In a word: no. Javascript is a client-side language. In order to do the things that you are describing, you need a server-side language such as PHP.
EDIT: OK, technically it is possible to implement Javascript in other areas besides the browser, but this is not very common.
5 YEAR EDIT: Well, 5 years later, this answer obviously is not accurate, with the popularity of things like node.js. Let that be a testament to how quickly things can change!
PHP and JavaScript are two different languages that do two different things. One cannot replace the other. You are most likely going to use a combination of the two. JavaScript for client-side stuff. PHP for server-side stuff.
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Occasionally I search for some JavaScript help and I come upon the term "Server-side JavaScript". When would you use JavaScript server-side? And how?
My experiences of JavaScript have been in the browser. Is there a compiled version of JS?
It's not AJAX, unless people are using the term improperly. As its name suggests, SSJS is JavaScript that runs on the server, interpreted by a standalone (i.e., browser-independent) JavaScript engine, like SpiderMonkey.
Why bother? Well, one area I currently see it underutilized in is in data validation. With SSJS you write one piece of code that then gets used on both the server and the client. Thus you get immediate user feedback from the client-side JS that will automatically match the data checking taking place on the server.
There's the project Phobos, which is a server side JavaScript framework.
Back In The Day, the Netscape web server offered server-side java script as well.
In both of these cases, JavaScript is used just like you'd use any language on the server. Typically to handle HTTP requests and generate content.
Rhino, which is Mozilla's JavaScript system for Java, compiles JavaScript in to Java byte codes, which the JVM can choose to JIT. Other systems use other means for executing java script, even to the point that some are JIT compiling their java script internal codes.
I foresee that there will be more and more JavaScript on the server. When you're writing "thick" applications in JavaScript on the client, then you may as well be able to write your logic in JavaScript on the server in order to not have to make the cognitive leaps from one language to another. The environments will be different, but much of your code and knowledge will be shareable.
Finally, JavaScript is probably the singular language that has the most money pointing at it right now in terms of implementations. From Apple, Mozilla, Google, and even Microsoft as well as the efforts to make it an even more advanced language (i.e. basically a Scheme with Algol syntax sans macros).
Most of those implementation are buried in the browser, but that's not to say that there's no value on the server side as well.
The tooling is the biggest place where JavaScript is lacking, especially on the server side, but if you consider something like Phobos, where you can debug your server side JavaScript in the IDE, that's a great advancement.
Personally, I'm tossing JavaScript around in my applications like white paint. It offers cheap extensibility for very little cost and is a great enabler.
2013's NEWS
Node.js (see also at Wikipedia article) is a sucess, and its community is growing!
MongoDB (at server), Chrome (at client), and Node.js (at server) use
V8 JavaScript engine.
PS: you can use only one language, Javascript, to all your project modules: client-APIs, client interface, "server hub", and server database (ex. stored procedures). All programmers "coding once"!
The main distinction between "Server-Javascript" and "Client-Javascript" languages, is explained at http://www.commonJS.org/ , the standard library for Server-Javascript.
CommonJS exists since 2009, and today (2013) is a mature standard, used in both, MongoDB and Node.js.
HISTORICAL NOTE: the oldest active "client+server Javascript" (including use of PostgreSQL) open package is alive! Released in 2001 and in continuous development since then, Whitebeam is a mature Javascript (and DOM) technology. The last update was in January 2016.
2016's NEWS
Node.js engine continues as a runtime built on Chrome's V8 JavaScript... And now is, in fact, a consolidated success! The last releases are v7.0 and v6.8 LTS.
JSON, as data interchange format, have continous growing interest in the last years, having surpassed in 2016 the interest in XML (see also in the Science context, where surpassed in 2011). As the native Javascript format, it is also a good language-trend indicator.
The (faster) V8 engine is also the most used, since 2014: in the most popular client (Chrome at desktops and WebView at Android) and popular at servers — Node.js as runtime and PostgreSQL with PL/V8 for SQL and stored procedures.
...Perhaps the most important server-side contribution in 2016 was a fast and robust database support for JSON and Javascript: with PostgreSQL 9.1+ (2016-10) you are able to load PL/V8 (and dialects like Coffeshop) via simple CREATE EXTENSION command; with PostgreSQL 9.5+ (2016-10) the most important, a complete orthogonal set of JSON and JSONb functions and operators.
So, as a fact, there is a fast, resilient and reliable unified JavaScript development stack.
Classic ASP was able to use JavaScript on the server, although most people used VBScript.
One compelling use of JavaScript on the server is as a complement to client-side data validation. For example, you might use the same JavaScript validation library on the client and on the server. This ensures you're using the same logic on the client as you are on the server, but (potentially) avoiding an unnecessary round-trip by pre-validating on the client side.
Wikipedia lists a number of server-side JavaScript implementations here.
It could refer to using javascript to post messages to a web server without re-loading the page: in other words, AJAX.
But more likely I think it means something like Aptana/Jaxer (or, today, Node.js), which uses javascript for a server-side language. In this case, remember that javascript is just a language: the DOM used in a web browser is a sort of API. The server-side javascript engines would provide their own API objects, geared at server-side tasks like DB and file system access.
Server-side javascript is an interesting idea because of the client-side validation problem: you want to do validation client-side to avoid sending needless requests to your server. This improves server performance and reduces latency on the client. But you must do validation server-side because you can't trust the client. This results in a lot of duplicate code between the client and server.
The theory is that if your client and server languages match you'll no longer need two implementations of the same logic. In practice it doesn't work so well, because the client and server views of a page request are so different and because you don't control the javascript engine used by the client.
It really depends if you are talking about ASP.NET or Classic ASP. If you are using ASP.NET there aren't many good reasons for using Javascript.
ASP Classic is an different case. You can use Javascript on the server side in ASP just the same way you would use VBScript. You can access the Application, Server, Request and Response objects just the same as via VBScript.
There can be real benefits to using Javascript on the server side in ASP rather than VBScript. It means you can share code between the browser code and server code. It also means your developers don't need to deal with two different languages.
There are some downsides to server side Javascript in ASP though. Firstly it doesn't appear to be as fast as VBScript on the server side at string concatenation. It also isn't as good as making calls to COM objects as VBScript (you can only get data back from COM calls via the return value, rather than via out/byref parameters).
You might want to have some functionality both in the browser and in the server to have the exact same implementation.
An example would be a renderer for a wiki-syntax, that you run in the browser for the WYSIWYG editor and on the server to render the resulting page. This way you know that both the rendered results will be exactly the same in both cases.
Apparently Rhino can compile JavaScript to Java classes.
Traditionally, Javascript runs around the Document Object Model. But what if you work for a Java shop and would like a scripting engine around your custom object model? That's when Server-side Javascript comes in.
http://en.wikipedia.org/wiki/Server-side_JavaScript
I remember with Cocoon (Apache's Java/XML/Javascript MVC framework) I used to use server-side Javascript since there was a something (I believe cforms) that needed to be written in Javascript and was running on the server even though I believe you could write it in Java.
We used Rhyno by that time, please check: http://peter.michaux.ca/articles/server-side-javascript-with-rhino-and-jetty
http://steve-yegge.blogspot.com/2007/06/rhino-on-rails.html
Check out how Steve Yegge is using Server-Side JavaScript with Rhino and why. He has a bunch of stuff on how he feels JavaScript is up and coming.
Yeah I've just read up about SSJS on a blog by some guy named John Resig.
He describes an engine called Jaxer, which he says is "Imagine ripping off the visual rendering part of Firefox and replacing it with a hook to Apache instead - roughly speaking that's what Jaxer is."
For anyone who knows ASP.NET The HTML looks familiar
<html>
<head>
<script src="http://code.jquery.com/jquery.js" runat="both"></script>
<script>
jQuery(function($){
$("form").submit(function(){
save( $("textarea").val() );
return false;
});
});
</script>
<script runat="server">
function save( text ){
Jaxer.File.write("tmp.txt", text);
}
save.proxy = true;
function load(){
$("textarea").val(
Jaxer.File.exists("tmp.txt") ? Jaxer.File.read("tmp.txt") : "");
}
</script>
</head>
<body onserverload="load()">
<form action="" method="post">
<textarea></textarea>
<input type="submit"/>
</form>
</body>
</html>
Note the runat="sever" and runat="both"
With ASP you can use Server Side JavaScript in a number of ways. The way I most commonly use it is to have the same code executing on the client and on the server for validation.
file.js
<!--//--><%
//javascript code
function example(){return "Hello, World!";}
//%>
file.html
<%#LANGUAGE="javascript"%>
<!-- METADATA TYPE="typelib"
FILE="C:\Archivos de programa\Archivos comunes\System\ado\msado15.dll" -->
<!--#include file="file.js"-->
<html>
<head>
<script language="javascript" src="file.js"></script>
</head>
<body>
<%=example();%>
<script language="javascript">alert(example());</script>
</body>
</html>
file.js starts and ends the way it does to allow for inclusion of the same file.