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).
Related
What are the techniques and the tools, libraries and frameworks necessary to make a SPA in java (and javascript)?
Consider an application served by a server A. This server might go offline.
What I need is a partially functional, read-only version of that application on a second server B, but fully navigable.
Server B can only serve static files: html, css, js, images.
Server A has access to server B and can push data to it as required and on a regular basis.
My second requirement is to suffer as less as possible from vendor lock-in, so I should be using as little frameworks as possible.
The third requirement is: there should be no necessity of any tool on the client's side, in the browser.
Please list the possible techniques, and where applicable, also at least one tool/framework/library, so I can search for alternatives to that one if, for whatever reason, it doesn't fit my bill.
If you accept any client-side code:
Yes, the best answer are service workers.
You can read about various caching techniques on Jake's site
Easiest plugin to make your website accessible offline is https://github.com/GoogleChrome/sw-precache.
Service workers are framework-agnostic, you can use them with all frameworks or without one in JavaScript.
You will need typical backend (Java/PHP?) or even static html files, and JavaScript client-side code.
If you don't accept any client-side code and accept 3rd parties:
The only solution is to have some kind of proxy like CloudFlare - your DNS will point to CloudFlare, and they you set up what will happen.
If you don't accept any cliend-side code and don't accept 3rd parties:
If you want your solution exactly as you've described, you should use some kind of load balancer like HAProxy (http://www.haproxy.org/), which will route your traffic to failover server. You can read about this here: http://blog.haproxy.com/2013/12/23/failover-and-worst-case-management-with-haproxy/
Currently, I am developing a 2-player tetris game. Originally, I was planning to implement a client-server model in a mobile environment.
However, now I change into web game, which is accessible by a browser. Since I am not used to a web development, I want to know if client-server model is necessary in a web game.
To be honest, I am a little bit skeptical writing both client and server code since a browser does a job to connect to the server.
Is it possible to build a network-based game by using only one server without a client part?
Is it possible to build a network-based game by using only one server without a client part?
Nope. You need a client.
It doesn't matter if you're in the browser or writing a native application. Yes, the browser solves a lot of client problems for you - it implements HTTP for you, and it has display (CSS), content (HTML), and evented logic (JavaScript) that you can use. But you still need to write your client using those technologies.
Even if the browser exposed a call in javascript like this:
window.startPeterHwangsTetrisGame();
You still have a client. The client is 1 line of code, and it is exactly the above script*.
Realistically, you should look for a game-oriented web development tutorial and start there.
*(aside from the necessary HTML within which that javascript exists)
Well, in one sorta correct way, no, because you're not redesigning the browser, but nobody would say it like that. Web design includes a lot of code / markup used on the client (browser), and while your server is sending the browser the data, and that data is a mix of CSS, HTML, and JavaScript (as well as media like graphics and perhaps music), the browser is the piece of software doing the lifting on those pieces once it receives them. That data is selected by the server, so the logic for that is on the server, but this is what people would think of as "client design" in the context of a web application.
There are also a number of models (ways of arranging your programming designs) which would lead to cleaner code, and a lot of these would send a grouping of information (called a model) to the client (the browser) and then the browser would do some interpretation of how to use that data (called a view). This is a simplification since I don't think you're ready for a big dive into specific theories, but you could start with a JavaScript and HTML tutorial and then learn a server language:
Python is my favorite, but PHP is big as is Java (NOT to be confused with JavaScript), and I make my living doing C#. Really there are plenty of great choices.
One commentator recommended Node.js because you'd use JavaScript on the server with Node--just like for the client part (the response data you're sending to the browser). That's double duty, but I am partial to Python (as I said). Just pick something, and as you learn, you'll get to know what you like. If you change languages, it'll be easier to learn your second one.
First off, I am not asking for any code or anything like that.
all I need is some advise.
I'm creating a roulette game and everything in my roulette game is based on jQuery.
however, as we all know, jQuery is client side so I was thinking about using AJAX to send some details back to server and from the server to the users browser so I can make this roulette game work in "multiplayer" fashion... But the issue is that I don't think its possible to send the roulette's wheel animation to the server and back to users browser so I am a bit confused about this!
In my research I came across some information (old ones) about using node.js and jquery together! I don't know if this is possible or how easy it would be to use my jquery code in node.js as I have never used node.js before..
so the question that i have is:
based on the information i provided above and my requirements, what are my options?
can I use AJAX to achieve what i am trying to do and if so, a bit
information would be great.
if AJAX is out of question, is it possible to use my jquery code in
node.js to achieve what I am trying to do?
ANY ADVISE WOULD BE APPRECIATED.
P.S. I don't want to use HTML5 as 1st I don't know much about HTML5 and also, some devices, browsers do not support it.
Thanks
The best way is to use websockets to ensure real time communication. One of the best alternatives for implementing that could be using a server under node.js. Have a look to this video from Code School node.js tutorials: https://www.youtube.com/watch?v=mtDK4jf4RS0 where is ilustrated how to implement a real time chat. Your problem is based on the same.
There are three parts to a multiplayer game displayed in a browser:
client-side display,
server-side data management,
client-server communication.
If you're already set on your display technology (jQuery), then you're probably going to use $.ajax() for client-server communication. However, technologies used for server-side data management are completely up to you and they don't necessarily have any connection to the technologies used for display and communication (meaning the traditional communication initiated by client).
Basically, use any kind of server technology stack you like. Node.js might do just fine but there are many other viable alternatives. They just need to support communication with the client.
So, to be absolutely clear, your question doesn't really make sense. You might use jQuery in the client and Node.js on the server, but they will never really "work together". They will manage completely separate parts of your application and connect through protocols not specific to either of them.
As for the animation, the animation itself is solely a client-side problem. If you want to "synchronize the animation" across multiple clients, you can let the clients communicate with the server, but they only ever need to send/receive plain data. Then you adjust the client-side animation based on the received data.
As another poster points out, websockets are a better fit for this than regular client-initiated HTTP requests. Not because of "the animation", but because you want all the clients to receive the information about the start of betting at the same time.
I am also developing a MMO game using javascript only. Firstly, there are two different types of javascript here. Usual client side javascript (the one you already know) and the server side javascript (i.e. Node.js).
You will need to develop both client and server before connecting them with jQuery's Ajax. So you need to study Node.js before designing overall architecture of your game.
I read many Node.js tutorials and watched many youtube tutorial videos but I was still confused, before I really sat down and read a good textbook that explained from basics, one like below. Try to get hold of it from your local library.
Express web application development learn how to develop web applications with the Express framework from scratch by Hage Yaapa
Express is the popular framework that runs on Node.js now. So it's worth getting familiar with Express Framework. Once you understand how express app works (not so difficult), you will see how you can frame your game structure like I did :)
In order for many clients to share same animation, there must a server that synchronizes the game state. Ajax can only link between server-client communication in my understanding. There is no mechanism that connects between clients. The clients ask server what number was the result of roulette roll and show the corresponding animations.
Yes, you can use NodeJS and jQuery together.
NodeJS is server-side, meaning that you set up a server (a lot of people use the Express module, which is easy to use), which serves content to clients asking for it. Your server-side code can be in any language supporting sockets, not just NodeJS. But NodeJS is easy to use if you know JS already.
jQuery is client-side, meaning that it's executed by the user's browser, and may or may not have a server-side component (if it doesn't need it), or it might have one where it sends requests to the server-side code. When it requests a page from the server, it can be static content (like when you request index.html) or dynamic via an AJAX request. Client-side browser code must be HTML/CSS/JS (you can't make Firefox or Chrome interpret C, for example).
It's quite hard for me to figure out if this sort of thing has ever been implemented. I want to look for any libraries that may exist so I don't go about reinventing the wheel.
I have this idea of having a web app that connects the people who are on the site. Every user that is connected to the site may communicate to another user also on the site via the server. So the protocols will be implemented in JavaScript, and the server simply helps to identify users, and just echoes data to enable the communication. For instance I can use this to implement my game networking ideas in javascript, and easily test them without having my testers download any executables, they can just log onto the site.
Now obviously this isn't going to be an effective architecture for any kind of serious application. But I think if I can get it working I could build really cool networking apps without having any sort of download.
What I'm thinking about is using ajax for client->webserver and webserver->client (Comet?) and I can code up the webserver echo bit with PHP or a cgi script. And then I can implement an entirely separate protocol in JS that the webserver does not care or know about.
The reason for having the webserver echo everything is because I don't want to use java or anything else that I can open up sockets in. Why make it harder for me? Because I can and because I happen to be really enamored with javascript at the moment. It's the only web technology I trust. Screw java applets.
Does this make any sense to anyone? Am I crazy?
Don't know about the crazy part (there's a proposal at area51, go check that) but it's definitely doable.
You could use a plain old XMPP server and a javascript XMPP client (there are libraries - for example strophe)
You could do it with AJAX and a PHP backend: Making an AJAX Web Chat
You could use the fancy Websockets from HTML5: Start Using HTML5 WebSockets
You could use some existing component if you can find any (I couldn't find any I would use)
Cheers :)
I'm starting a new Facebook canvas application so I can pick the technology I'm going to use. I've always been a fan of the .NET platform so I'm strongly considering it for this app. I think the work done in:
facebooksdk.codeplex.com
looks very promising. But my question is the following:
It's my understanding that when using an app framework like this (or PHP for that matter) with Facebook, whenever we have a call into the API to do some action (say post to the stream), the flow would be the following:
-User initiates request which is direceted to ASP.NET server
-ASP.NET server makes Facebook API call
so a total of three machines are involved.
Why wouldn't one use the Javascript SDK instead?
http://developers.facebook.com/docs/reference/javascript/FB.api
"Server-side calls are available via the JavaScript SDK that allow you to build rich applications that can make API calls against the Facebook servers directly from the user's browser. This can improve performance in many scenarios, as compared to making all calls from your server. It can also help reduce, or eliminate the need to proxy the requests thru your own servers, freeing them to do other things."
So as I see it, I'd be taking my ASP.NET server out of the equation, reducing the number of machines involved from three to two. My server is under less load and the user (likely) gets fatter performance.
Am I correct that using the Facebook C# SDK, we have this three machine scenario instead of the two machine scenario of the JS API?
Now I do understand that a web server framework like ASP.NET offers great benefits like great development tools, infrastructure for postbacks, etc, but do I have an incomplete picture here? Would it make sense to use the C# framework but still rely on the javascript sdk for most of the FB api calls? When should one use each?
Best,
-Ben
You should absolutely use the Javascript SDK when you can. You are going to get a lot better performance and your app will be more scalable. However, performance isn't always the only consideration. Some things are just easier on the server. Also, a lot of apps do offline (or delayed processing) of user data that doesn't involve direct interaction.
I don't think that there is a right or wrong place to use each SDK, but they definitely both have their place in a well built Facebook app. My advice would just be to use whichever is easier for each task. As your app grows you are going to learn where the bottlenecks are and where you need to really squeeze that extra bit of performance is needed by either moving stuff to the client (Javascript SDK) or moving stuff to be processed in the background (Facebook C# SDK).
Generally, we use the Javascript SDK for some authentication stuff and for most of the stuff with the user interface. The one exception to the UI stuff is when we are really concerned about handling errors. It is a lot easier to handler errors on the server than with the Javascript SDK. Errors I am talking about are things like errors from facebook or just general facebook downtime.
Like I said, in the beginning just use both and do whatever is easier for each task.