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I've made some a couple of chess engines in Processing (a simplified Java language) and wanted to make one on a website. I'm guessing JavaScript would be the most obvious thing to make it in, but I wanted to know if there are other options before I get into it. I've never made something that processing intensive for web.
I've looked around and it seems like C++ can somehow be made to work with web code but I've never done that and don't know much about it. Is it possible to do the low intensive things like drawing in JavaScript and the move generation in C++? Is there a better option?
Edit: I put Processing (the language) in bold to differentiate it
If you're looking for a cross browser client-side solution, then there is no single cross-browser way to use C++ in your viewer's browser. Cross browser solutions consist of javascript (recommended), java (being phased out on desktops and generally not available on mobile) and Adobe Flash (not available on mobile).
If you want it all client-side, what I would suggest is that you write in client-side javascript and do as much processing as you can in webworkers which are separate threads of execution. Those separate threads can do as much calculation as you want, but need to use messaging to communicate back to the main javascript thread in order to actually modify the DOM or interact with the user.
Or, as a browser web-app, you could keep the chess logic on the server in C++ or whatever server-side language you want to use and use client-side Ajax calls to ask the server to calculate the next move.
It depends upon how you want to architect this.
If you want to make it run without server-side support, you will pretty much limited to JavaScript. (Sure, you could actually host your existing Java code and libraries, available as a Java applet - or something in Flash or another plugin for that matter - but especially given HTML 5, etc., the focus is on JavaScript.)
Otherwise, you can implement the UI and other elements with JavaScript, and use AJAX to have it communicate / offload the heavy processing to a back-end server. (At this point, you would essentially need to host a chess engine for use from your website.)
Write the chess engine with any language you so desire. Create an interface for communicating with your chess engine or even better use an existing standard chess engine interface. Use either of the following two "standard" interfaces
http://en.wikipedia.org/wiki/Chess_Engine_Communication_Protocol
http://en.wikipedia.org/wiki/Universal_Chess_Interface
Once you have thoroughly debugged your chess engine and are happy with it, you can approach the problem of writing a web UI for it as a completely independent problem. You can accomplish communication between a chess engine server and a web-server/website by an intermediate layer of your choice. One such option is:
http://en.wikipedia.org/wiki/Ajax_(programming)
Furthermore, if you use a standard chess interface you can swap out your own chess engine for any third party chess engine satisfying the interface that you chose.
How important is it to gracefully degrade or inversely Progressively Enhance the UI experiance? I mean am I going to lose a LOT of business if I don't? Do you practice this concept? Are there any web 1.0 users still left out there?
Please could you also include if you practice this personally and how much time you've spent relative to the entire project. I realize every project is different, I want to get a sense of how much time as a general rule I should be allocating toward this goal.
EDIT
Firstly, i'm looking for guidance around how much time I should be devoting to making my applications run without javascript.
Secondly, the BS term "web 1.0" (...lol... I don't really like it either) works because we all understand that as the iteration before ajax and all its goodness.
Thirdly, the kind of applications I'm describing are the ones we are all building, not Facebook, not Twitter (unless you're from Facebook or Twitter) but service or utitlity programs like a web calendar, or an online todo list or [INSERT YOUR APP HERE].
Progressive enhancement is more a mindset than a particular task that you need to allocate time to. If you're doing it right (and if it's important to you), you should be enhancing the user experience with JavaScript, but not relying on it.
For example, a link will point to a new page, but with JavaScript you'll disable the link and load new content into the current page with Ajax. Start off without JavaScript and progressive enhancement will follow naturally.
Progressive enhancement is not only smart but it is faster and easier to develop.
And at each stage, you almost always have a working fall-back.
Here's what it looks like in a nutshell:
Boss/client approves mock ups.
We code to valid HTML output. At this point, the boss/client can start using the site. Baring any boss/client changes, the HTML is mostly done. The site is usable at this point.
We start tweaking the CSS to make it match the boss/client's graphic expectations. Changes to the HTML are minor, if any.
In parallel, JavaScript is added to do non-critical, but nice, things. (Sort tables, Fancy CSS helping, replace some links with AJAX calls, warn the user -- client-side -- of input problems.)
If any one of these things breaks, the site still works.
Also, little, or usually no, html changes are needed.
First of all, lets not start using bullshit terms like "web 1.0" and "web 2.0" etc, the fact is the web is forever progressing and new websites are starting to use JavaScript to enhance the user experience.
I don't know anyone that doesn't allow their site to gracefully degrade when JavaScript isn't available, this is for the same reason we use semantic markup so screen readers can correctly interpret our websites for users with visual impairment, and whilst the vast majority of your visitors / users won't fall into these categories it's still important to think about the minority.
Will you lose a LOT of business, well that depends on how successful you are now and how badly your site degrades, chances are you probably won't lose any business... but that should not be the measure yo use to decide whether to gracefully degrade a website.
So unless you can come up with a pretty good reason, you should probably use JavaScript for the purposes of progressive enhancement, don't depend too much on it.
:-)
This greatly depends on the nature of your aplication and its data. If it's something that you know will be mostly used via computers, than degrading to non-script version UI wouldn't make any obvious benefit (even loss of money because it will take considerable time to develop). You can always tell people to enable javascript in their browsers (similar to what's done here on Stackoverflow - try disabling script and reload the page). Your app/site should display at least something when there's no Javascript posibility.
But if your application has simple data to display and users should access it frequently wherever they are, than degrading to lesser browsers (without script engines like Opera Mini) is a must. Creating a separate UI will less functionality, but keeping everything in that users need to access is probably your best option. UIs like separate iPhone applications for example...
JavaScript is disabled by a small proportion of web users, but when you start to talk big volumes this can make a difference. For example for 1 million visitors, you can expect more than 10,000 not to be able to user your site.
You should decide how much lost business is worth the additional cost of having a non-JavaScript version of your site.
You can have an approach where the entire site may not work without JavaScript but that some of the core features are there.
Many years back, I was told that Javascript was harmful, and I remember being annoyed with endless popup when I right-clicked an image to download it.
Now it seems suddenly that Javascript is great, and you can do a lot of things with it to let users have native-like web application experience.
I admit I have missed 6-7 years of Javascript literature, so I hope to start anew with SO kickstarting me to understand the following:
Is Javascript mainly concerned about user interface i.e. smoothen interaction between application and users and not about logic processing, number crunching or form processing etc.?
Can Javascript write to local hard drive (besides cookies)?
Can Javascript web application run with Javascript capabilities in browsers turned off? (I would think outright no, but an article on Adaptive Path said 'maybe')
Is AJAX illegal to use due to Eolas patent claim? Is it worth it spending effort learning it when the future is not secure? (I know AJAX is not Javascript)
Thanks. Hoping for enlightenment.
Yes. JavaSscript is usually used to enhance the user's experience and make the site easier to use. It is also possible to delegate validation tasks and the like to JavaScript, however (though this should never absolve the server of its responsibility to check input).
No.
That depends on how the application is written. If it's done properly, then the JavaScript will merely enhance the interface, and the application will still work without it; this is called progressive enhancement.
Not at all. AJAX is used extensively on this very site!
One reason for the resurgence of popularity for JavaScript lately is the emergence of several frameworks. These make the process of writing JavaScript much, much easier, allowing tasks that would previously have been horribly complex to be implemented with minimal time and effort. The most popular of these is jQuery, which is a good place to start if you're intending to get in on the action.
Overall, JavaScript is a very powerful tool that allows you to create very rich interfaces. Well worth learning.
Yes, Javascript is all about client side processing, but also about AJAX where it calls back to the server asynchronously so that users do not see pages reloading.
No
No, but there are ways to gracefully degrade the experience for non javascript users. It requires carefult planning however.
No, that lawsuit was just about the browser technology that enables it. As a developer you dont have to worry about that.
Can Javascript write to local hard drive (besides cookies)?
Not really. However, as HTML5 support becomes more widespread you'll be able to use things like Web Storage and Web SQL. You won't be able to write arbitrary files on the user's hard drive, but using those two technologies you'll be able to persistently store and access data.
Can Javascript web application run
with Javascript capabilities in
browsers turned off? (I would think
outright no, but an article on
Adaptive Path said 'maybe')
It really depends on how you define "web application." You can write web apps without using Javascript for anything but UI candy, in which case you can degrade gracefully without without it. However, it's also possible to write web apps that rely heavily (entirely, even) on Javascript, which will utterly fail without it.
Is AJAX illegal to use due to Eolas
patent claim? Is it worth it spending
effort learning it when the future is
not secure?
I'm not a lawyer, but I'd agree with the other answers -- you shouldn't worry about it. I'm certainly still writing AJAX stuff :)
Is Javascript mainly concerned about
user interface i.e. smoothen
interaction between application and
users and not about logic processing,
number crunching or form processing
etc.?
It's about both. And more than that.
Javascript has really come into its own in the past few years. Browsers have gotten a lot faster at executing it quickly, and people have been figuring out new ways to use the language itself to its full potential. You can really start using Javascript like a full-out application programming language, and not just to write little scripts that animate something or validate input.
If you're just getting back into the language and haven't read Crockford yet, I would highly recommend it. It's a great starting point to realizing the full potential of Javascript.
Edit: Some good Crockford Links
Javascript: The World's Most Misunderstood Programming Language
Javascript: The Good Parts (This is a presentation. Crockford also wrote a book by the same name that I haven't read myself, but I hear it's quite excellent.)
It's mainly for UI, but it can be used to save server-time on some operations (for example, Mathoverflow uses it to render LaTeX) and it's becoming popular to do so. But when you do this, you need to be respectful of the end-users time, because JavaScript can hold up some browsers, while it runs. But in general, it's a good and interesting idea.
Not without permission
If it's written correctly, it can. It's called "Graceful degredation" (some other variant terms exist, but the idea is the same). The basic idea is that you have it such that the JavaScript fails 'gracefully', and links that would normally get handled via JavaScript (i.e. to do some inline next-paging) will navigate to a 'backup' page that shows the relevant content.
I don't know about that, but AJAX can be implemented in different ways, XMLHTTPRequest is just one of them :) (And the most common, and suitable). Generally you like a library do this for you anyway (jQuery, or otherwise) but you can do it yourself for fun.
Yes, in my experience JavaScript is generally used to create a streamlined interface and relays information from the client to a server application for processing.
Yes, if the browser is configured to allow this (most aren't by default since this can be very dangerous).
No, JavaScript will not run if the browser is configured to have JavaScript disabled.
I wouldn't forgo learning JavaScript for this reason - as for the legality of the whole thing I wouldn't feel comfortable advising you about this. Still I think JavaScript is worth learning in spite of this situation.
The Eolas patent covers the embedding of objects in a HTML document (see US patent 5,838,906 titled "Distributed hypermedia method for automatically invoking external application providing interaction and display of embedded objects within a hypermedia document") ... this scope would not seem to include AJAX as a suite of technologies (being essentially scripting in a document to load content elements).
Partial answers:
I think all the security vulnerabilities associated with javascript have been fixed? IIRC the problems weren't with javascript, they were with particular browser's implementation of javascript.
I wouldn't worry about any patent claims on the AJAX technology. Patent sueing and counter-sueing is common place in the software world and invariably ends up with the affected parties licencing each other's technology. AJAX is not going anywhere :)
Preamble
So, this question has already been answered, but as it was my first question for this project, I'm going to continue to reference it in other questions I ask for this project.
For anyone who came from another question, here is the basic idea: Create a web app that can make it much easier to create other web applications or websites. To do this, you would basically create a modular site with "widgets" and then combine them into the final display pages. Each widget would likely have its own set of functions combined in a Class if you use Prototype or .prototype.fn otherwise.
Currently
I am working on getting the basics down: editing CSS, creating user JavaScript functions and dynamically finding their names/inputs, and other critical technical aspects of the project. Soon I will create a rough timeline of the features I wish to create. Soon after I do this, I intent to create a Blog of sorts to keep everyone informed of the project's status.
Original Question
Hello all, I am currently trying to formalize an idea I have for a personal project (which may turn into a professional one later on). The concept is a reflective web application. In other words, a web application that can build other web applications and is actively used to build and improve itself. Think of it as sort of a webapp IDE for creating webapps.
So before I start explaining it further, my question to all of you is this: What do you think would be some of the hardest challenges along the way and where would be the best place to start?
Now let me try to explain some of the aspects of this concept briefly here. I want this application to be as close to a WYSIWYG as possible, in that you have a display area which shows all or part of the website as it would appear. You should be free to browse it to get to the areas you want to work on and use a JavaScript debugger/console to ask "what would happen if...?" questions.
I intend for the webapps to be built up via components. In other words, the result would be a very modular webapp so that you can tweak things on a small or large scale with a fair amount of ease (generally it should be better than hand coding everything in <insert editor of choice>).
Once the website/webapp is done, this webapp should be able to produce all the code necessary to install and run the created website/webapp (so CSS, JavaScript, PHP, and PHP installer for the database).
Here are the few major challenges I've come up with so far:
Changing CSS on the fly
Implementing reflection in JavaScript
Accurate and brief DOM tree viewer
Allowing users to choose JavaScript libraries (i.e. Prototype, jQuery, Dojo, extJS, etc.)
Any other comments and suggestions are also welcome.
Edit 1: I really like the idea of AppJet and I will check it out in detail when I get the time this weekend. However, my only concern is that this is supposed to create code that can go onto others webservers, so while AppJet might be a great way for me to develop this app more rapidly, I still think I will have to generate PHP code for my users to put on their servers.
Also, when I feel this is ready for beta testers, I will certainly release it for free for everyone on this site. But I was thinking that out of beta I should follow a scheme similar to that of git: Free for open source apps, costs money for private/proprietary apps.
Conceptually, you would be building widgets, a widget factory, and a factory making factory.
So, you would have to find all the different types of interactions that could be possible in making a widget, between widgets, within a factory, and between multiple widget making factories to get an idea.
Something to keep on top of how far would be too far to abstract?
**I think you would need to be able to abstract a few layers completely for the application space itself. Then you'd have to build some management tool for it all. **
- Presentation, Workflow and the Data tier.
Presentation: You are either receiving feedback, or putting in input. Usually as a result of clicking, or entering something. A simple example is making dynamic web forms in a database. What would you have to store in a database about where it comes/goes from? This would probably make up the presentation layer. This would probably be the best exercise to start with to get a feel for what you may need to go with.
Workflow: it would be wise to build a simple workflow engine. I built one modeled on Windows Workflow that I had up and running in 2 days. It could set the initial event that should be run, etc. From a designer perspective, I would imagine a visio type program to link these events. The events in the workflow would then drive the presentation tier.
Data: You would have to store the data about the application as much as the data in the application. So, form, event, data structures could possibly be done by storing xml docs depending on whether you need to work with any of the data in the forms or not. The data of the application could also be stored in empty xml templates that you fill in, or in actual tables. At that point you'd have to create a table creation routine that would maintain a table for an app to the spec. Google has something like this with their google DB online.
Hope that helps. Share what you end up coming up with.
Why use PHP?
Appjet does something really similar using 100% Javascript on the client and server side with rhino.
This makes it easier for programmers to use your service, and easier for you to deploy. In fact even their data storage technique uses Javascript (simple native objects), which is a really powerful idea.
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Does anyone see server-side JavaScript taking off? There are a couple of implementations out there, but it all seems to be a bit of a stretch (as in, "doing it BECAUSE WE CAN" type of attitude).
I'm curious to know if anyone actually writes JavaScript for the server-side and what their experiences with it have been to date.
Also, which implementation is generally seen as the most stable?
I like to read Googler Steve Yegge's blog, and recently I came across this article of his where he argues that Mozilla Rhino is a good solution for server-side JS. It's a somewhat sloppy transcript, you might prefer to watch the video of the talk. It also offers a little bit of insight on why he thinks server-side JS is a good idea in the first place (or rather, why he thinks that it's a good idea to use a dynamic language to script Java). I thought the points he makes were convincing, so you might want to check it out.
A while earlier, he also posted something about dynamic languages in general (he's a big fan of them), just in case you were wondering why to use JS at all.
Why would you want to process
something in Javascript when you can
process it in PHP or ASP.NET which are
designed specifically for this task?
Perhaps because JavaScript is a more powerful programming language than those two? For example, it has functions as first-class data types and support for closures.
Steve Yegge has blogged about porting Ruby on Rails to server-side JavaScript as an internal project within Google ("Rhino on Rails"). He did it because he likes Rails but using Ruby isn't allowed within Google.
Before it was acquired by Google, JotSpot used server-side JavaScript to let you query their database and display your pages. They used Rhino to do it. CouchDB uses server-side JavaScript to create views of their database.
As you can see from these examples, a great way to use JavaScript on the server is for plugins. One of the reasons it's used is that you can create a very isolated sandbox for people to run their code in. Also, because of the way that JavaScript as a language works, you can provide a user tooling specifically honed to the tasks your users need to complete. If you do this right, users don't need to learn a new language to complete their tasks, a quick glance at your API and examples is enough to get them on their way. Compare this to many of the other languages and you can see why using server-side JavaScript to provide a plugin architecture is so enticing.
A secondary popular solution, one which can be seen through a project like Jaxer, is that a common problem of web applications that do client-side validation is that, since JavaScript is easily bypassed in the browser, validation has to be run once again on the server. A system like Jaxer allows you to write some validation functionality that is reusable between both server and client.
Support for JS on the server has been getting stronger and the number of frameworks is getting bigger even faster.
Just recently the serversideJS group was founded. They have a lot of smart people that have been working on serverside JS for years (some of them more then 10).
The goal for this project is to create
a standard library that will
ultimately allow web developers to
choose among any number of web
frameworks and tools and run that code
on the platform that makes the most
sense for their application.
to the people who say "why would you choose JS over java or any other language?" - you should read this Re-Introduction by Crockford and forget about the DOM - the DOM is superugly, but that's not JS fault and JS is not the DOM.
I've never even heard of this, but it strikes me as using the wrong tool for the job. Since programming languages are just tools designed to help us solve some problem.
Why would you want to process something in Javascript when you can process it in PHP or ASP.NET which are designed specifically for this task?
Sure you can pound a nail in with a screw driver, but a hammer works much better because it was actually designed for it...
So no, I don't see it taking off.
Well, plain ol' ASP supported JavaScript server-side years ago and everyone onad their dog used VBShiate instead. But I have to agree with the others: JS does not seem to be the right tool here - and I love to do client-side JS :)
I personally did a whole site in server side JavaScript using ASP. I found it quite enjoyable because I was able to have some good code reuse. This included:
validation of parameters
object modeling
object transport
Coupled with a higher-level modeling tool and code gen, I had fun with that project.
I have no numbers on perf unfortunately, since it is used only on an intranet. However, I have to assume performance is on par with VBScript backed ASP sites.
It seems like most of you are put off by this idea because of how unpleasant the various client-side implementations of Javascript have been. I would check out existing solutions before passing judgment, though, because remember that no particular SS/JS solution is tied to the JS implementations currently being used in browsers. Javascript is based on ECMAScript, remember, a spec that is currently in a fairly mature state. I suspect that a SS/JS solution that supports more recent ECMA specs would be no more cumbersome than using other scripting languages for the task. Remember, Ruby wasn't written to be a "web language" originally, either.
Does anyone see Server-side Javascript
taking off?
Try looking at http://www.appjet.com a startup doing hosted JavaScript applications to get a feel for what you can do. I especially like the learning process which gently nudges the user to build things with a minimal overhead ~ http://appjet.com/learn-to-program/lessons/intro
Now it might seem a weird idea at the moment to use JavaScript but think back when PC's started coming out. Every nerd I knew of was typing away at their new Trash-80's, Commodore64's, Apple ]['s typing in games or simple apps in BASIC.
Where is todays basic for the younger hacker?
It is just possible that JavaScript could do for Web based server side apps as BASIC did for the PC.
XChat can run Javascript plugins.
I've some accounting software completely written in Javascript.
There's this interesting IO library for V8: http://tinyclouds.org/node/
CouchDB is a document database with 'queries' written in Javascript (TraceMonkey).
Considering this, i believe, server-side Javascript did take off.
Server-side programming has been around for a lot longer than client side, and has lots of good solutions already.
JavaScript has survived and become popular purely because developers have very little choice in the matter - it's the only language that can interact with a DOM. Its only competition on the client side is from things like Flash and Silverlight which have a very different model.
This is also why JavaScript has received so much effort to smart it up and add modern features. If it were possible for the whole browser market to drop JavaScript and replace it with something designed properly for the task, I'm sure they would. As it stands Javascript has strange prototype-based objects, a few neat functional programming features, limited and quirky collections and very few libraries.
For small scripts it's fine, but it's a horrible language for writing large complicated systems. That things like Firefox and Gmail are (partly) written in it is a heroic accomplishment on their part, not a sign that the language is ready for real application development.
Flash Media Server is scripted by using Server Side Action Script, which is really just javascript (ECMAScript). So, I do it a lot. In fact, most of my day was dealing with SSAS.
And I hate it. Though to be fair, a bunch of that is more related to the (not so great) codebase I inherited than the actual language.
I think server-side Javascript is guarenteed to take off. Its only a matter of time.
Mozilla, Google, and Adobe have so much vested interest for Javascript that it would take a miracle to dislodge it from the browser world. The next logical step is to move this into the server-side.
This is a step towards moving away from the hodge podge of Internet technology that usually includes all of these
HTML
CSS
Javascript
Serverside Language J2EE/ASP/Ruby/Python/PHP
SQL
I haven't heard much about the current state of Javascript Server frameworks, except that they are mostly incomplete.
I see server-side js will offer considerable advantages in future applications. Why? Web apps that can go offline, client-side db store, google gears, etc...
Following this trend, more and more logic are moving into the client-side. Use an ORM that works for client-side, and use another on server-side (be it PHP / Ruby / whatever), write your synchronization logic twice in two different languages, write your business logic twice in two different languages?
How about use js on the client AND the server side and write the code once?
Convincing?
Personaly i've been developing and using my own JavaScript framework for about 4 years
now.
The good thing about JS on serverside is that implemented in ASP Classic you don't need
any other plugin or software installed, besides i'm also using my javascript (client)
framework on my server, that allows me to enjoy of the same functionality and proven
performance of my functions at both environments client and serverside.
Not only for data validation, but also lets say HTML or CSS dynamic constructions
can be done client or serverside, at least with my framework.
So far it works fast, i have nothing to complain or regret except its great usability
and scalability that i have been enjoying during this past 4 years, until the point
that i'm changing my ASP Classic code to javascript code.
You can see it in pratice at http://www.laferia.com.do
Node.js has taken off and proven that server-side JavaScript is here to stay =)
I can't see most developers getting over their distaste for client-side JavaScript programming. I'd rather go to Java for server-side stuff before choosing JavaScript.