Has anyone an idea for the following scenario?
I have a RIA-Webapplication (realized in ExtJs). What I want to implement is the possibility to use local ressources like card readers or fingerprint readers or other serial devices and filesystem access.
I thought about implementing this with a local websocket service which has to be installed by our customer before using our RIA the first time. When the webapp is loading it should scan the local machine if a websocket service is available and connect to it.
After that, local events (like new card is beeing read or recognized new finger) should be passed to the browser via websocket connection.
Any ideas how to get started with such a solution?
I have made something like that. Besides the obvious things such as read/write/poll data from the card-readers and so on, you would have to either implement everything yourself or, use a library for technology you are going to employ for your web-server. So, if you use a LAMP solution, i think there are some web-socket libraries for PHP that you can use. However, if you do everything by yourself then you have to implement everything from hand-shaking, to creating data packets. I have done everything from scratch by using .NET and it provides a number of useful libraries such as hashing. Java also would be a good option and have those kind of libraries as well. In general if you doing everything by yourself i would say the trickiest thing would be to split the data you want to transmit among various data packet. It is not that hard to do things from scratch. The RFC (https://www.rfc-editor.org/rfc/rfc6455) helped me a lot. Hopefully, this helps.
Related
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).
I've done some research and I've noticed that in a lot of examples Symfony2/AngularJS apps the frontend and backend are combined; for example, views use Twig.
I'd always thought that it's possible (and common practice) to create the frontend and backend separately and just join them by API. In that case if I want to change a PHP framework I will can do it without any problems and it will be enough to keep API.
So what are the best practices for doing it? It would be great if you could explain it to me and even greater if you just give me a link to good example on github or something.
We have been developing some projects using the same approach. Not only I think it doesn't have any "side effect", but the solution is very elegant too.
We usually create the backend in Node.js, and it is just an API server (not necessarily entirely REST-compliant). We then create another, separate web application for the frontend, written entirely in HTML5/JavaScript (with or without Angular.js). The API server never returns any HTML, just JSON! Not even an index structure.
There are lots of benefits:
The code is very clean and elegant. Communication between the frontend and the backend follow standardized methods. The server exposes some API's, and the client can use them freely.
It makes it easier to have different teams for the frontend and the backend, and they can work quite freely without interfering with each other. Designers, which usually have limited coding skills, appreciate this too.
The frontend is just a static HTML5 app, so it can (and we often did) easily be hosted on a CDN. This means that your servers will never have to worry about static contents at all, and their load is reduced, saving you money. Users are happier too, as CDNs are usually very fast for them.
Some hints that I can give you based on our experience:
The biggest issue is with authentication of users. It's not particularly complicated, but you may want to implement authentication using for example protocols like OAuth 2.0 for your internal use. So, the frontend app will act as a OAuth client, and obtains an auth token from the backend. You may also want to consider moving the authentication server (with OAuth) on another separate resource from the API server.
If you host the webapp on a different hostname (e.g. a CDN) you may need to deal with CORS, and maybe JSONP.
The language you write the backend in is not really important. We have done that in PHP (including Laravel), even though we got the best results with using Node.js. For Node.js, we published our boilerplate on GitHub, based on RestifyJS
I asked some questions in the past you may be interested in:
Web service and API: "chicken or egg"
Security of an API server: login with password and sessions
Anyone knows a good tutorial/js plugin to create a multi user html5 sketch web application?
Would be nice to have cross browser compatibility, preferably without any tools that need to be installed server side.
If the latter is not possible, I would also be happy if the application just saves the user x's sketch so that next time someone loads the app, it would show user x's sketch on startup.
Thanks for your advise.
PS. I have looked at Mr. Doob's, he uses node.js, unfortunately my hosting does not support this just yet. Hence I am asking for a solution that need no server side installation. Also the multi user drawing pad by Union Platform seems to fit the bill, but unfortunately it also requires something to be installed.
If you're willing to shift to a new web host for this application you can use Heroku. Heroku is free and supports Node.js.
I created a multi-user Agile project management whiteboard using WebSockets and Node.js and found a 624% increase in requests per second vs using HTTP. I use MongoDB on the back end which allows you to store data as serialized JSON... this means you can send JSON between client <-> Server <-> Database with no parsing (very fast).
Hope this helps!
The reason Mr. Doob's implementation uses Node.js is because node is great at this kind of things. Since this is going to involve delivering realtime changes to different users, your best bet is to use Comet/Ajax-Push/Longpolling. And if you want to support multi-window usage(multiple browser tabs having your sketchpad), you would need to implement http connection pooling to get around the connection limits set by browsers as per http standard.
If you can't use websockets which are fairly new anyways, Then I would suggest using ajax polling of some sort. Basically use ajax calls based on a delay.
This wikipedia article shows some of the various options you should do further reading into.
http://en.wikipedia.org/wiki/Comet_%28programming%29
I'm going to build an webbased application which is controlling and monitoring tons of realtime data. think about few thousand valves pipes pumps and sensors.
Please list a technology stack you would use to build a realtime website with an educated guess about performance. The environment is 'ideal' all openstandards are available. so no IE6 etc backward compatibility is needed. Current and future proof technologies please.
server side:
database web-server - which one / combination makes it easy to support real-time pushing of data?
client side:
what kind of client environment (javascript Libraries) support showing and updating tons of realtime data?
You can have a look at Goliath
I recommend you have a look into Socket.IO which works best with Node.JS and might be the best fit for handling many long lasting concurrent real time connections. I would say that the choice of the database depends more on where your real time data is coming from and how it is supposed to get in the database.
Me too. So I'm writing a frame work that can do that. It's based on lighttpd front end, and multiple fcgi backend servers. The original Android was also tested with another framework that is based on it. It's open source so you might want to use it as a starting point.
I haven't been able to write a realtime app, but I've dabbled a bit with http://socket.io/ and node.js, and it's a joy to get started with.
App engine has a js channel api which seems nice. You should take a look to see if hosting on app engine is a option.
If you're dealing with "real time" stuff server-side, I recommend clojure for managing concurrent state.
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 :)