I am working on an application in Linux which will interfaces with hardware. One of the requirements is to create the GUI in Web-browser . the application will be c++ based. I m not familiar with web realted stuff so i want to know Is it possible to do such a thing (currently it's a console application take input from txt file/cmd line). gui will be simple using button and showing output messages on browser from the application. i want to know which technologies/languages are involved and how can it be done. some of the idea i read but havn't found anything concrete yet. if u have any idea about these or a better suggestion please share
run the app in background and communicate with browser ?
call library functions directly from browser ?
any other idea ?
I would start by setting up a regular HTTP server, like lighttp or Apache httpd.
You say you already have a command line program that does the actual work - As a first step, I would reuse that, and configure the web server to call your program using CGI - see forexample http://httpd.apache.org/docs/2.2/howto/cgi.html for apache
Finally, I'd pick some javascript framework like jQuery or YUI with Ajax capabilities to do requests to the server to call the CGI script from within a webpage. You could also create a form-based web application without ajax or any framework, but that would require you to stuff all kinds of logic in your program to generate HTML pages. By using Ajax, you can leave the command line application as is, and parse any responses it gives with javascript, and then use that to dynamically change the webpage in a way that would make sense to the user.
If this all works, then I would try to figure out how to package all these components. Perhaps you just want to create a simple archive with all the programs inside, or maybe you want to go as far as actually embedding the webserver in your program. Alternatively, you may want to do it the other way around and rewrite your program as an ISAPI module that you can plug into your webserver. Or if that's not integrated enough still you could write your own (partial) HTTP server. That's really up to you (I'd probably spend time and energy on searching for the leanest, meanest existing open source http serverr and use that instead)
At any rate, the prior steps won't be lost work. Most likely, developing the web page is going form a substantial part of the work, so I would probably create a quick and dirty working solution first using the age-old CGI trick, and then develop the webpage to my satisfaction. At that point you can already have an acceptable distributable solution by simply putting all programs in a single archive (of course you would have to tweak the webserver's configuration too, like changing the default port so it won't interfere with existing webservers.) Only after that I would spend time on creating a more integrated fancy solution.
I ended up using Wt though I'd update for future reference.
These are how I thought of doing this, in order of complexity for me:
Create a simple server-side-language (PHP/Python) website that can communicate with (ie launch and process the return of) your application
Modify your application to have a built-in webserver that just punched out HTML (command line parameters taken through the URL)
Modify the app to publish JSON and use javascript on a simple HTML page to pull it in.
You could write a Java applet (as you've tagged this thread) but I think you'd be wasting time. This can be quite simple if you're willing to spend 10 minutes looking up a few simple commands.
After 12 years, web browser-based GUI started to appear, WebUI is one of them.
Related
I want some way of creating a dedicated browser window for a browser (chrom-e/ium or firefox). Its content needs to be controlled by a java application (a http call to localhost or better a more direct way of communicating). These two should be bundled together in some way.
A little Background
I want to write a java desktop app but don't want to use Swing or javaFX for the UI. The UI should be written like a one page app and may be ported (at least partially) to the web. I have taken a look at the javafx WebView but would rather have a full fledged browser on my hands. It would also be nice to have a little more control over said browser to send files and read files in a more desktopish way. The only real requirement is that there has to be some java backend behind it and that is has to work offline.
Is something like this possible at all or is it just a pipe dream?
I am very almost a year late for the party, but:
There are a few (that I know) technologies that can help you:
Electron. It is basically what you want, you can use web
technologies to "forge" a desktop app, it's quite well known, I never used it but for what I have read that you can stick almost anything to it's "backend".
JavaFxWebView. There are some really nice ways to use it, you can
even use bootstrap and AngularJs, here is a example (not by me)
Yes it's possible and not all that unusual. Your app can open a default browser as described here -
https://stackoverflow.com/a/10967469/5087125
And then proceed to respond to http requests to your app.
Today I'm using an applet to modify client-side information, considering the new browsers i have to found out a new workaround to continue modifying file and execute windows command at client-side because some browser are suspending the applet execution.
Any ideia for solution that has allow windows command execution and access file at client side like Activex ?
Applets have always been sitting between webapps and desktop apps. In that sense, what you want to achieve is exactly what every hacker in the world wants to achieve, that is gain access to your computer from a browser. And I think it would fair to say that for that reason, applets are dying and are not coming back from the dead anytime soon.
But unfortunatly some functionalities need applets to run, and what you can do really depends on those functionalities.
Statu-quo
They are still working in IE (not Edge), Firefox and Safari. If you control your clients environment you can maybe still use them as is. But for how long ?
Move to Server
You move your functionalities on the server. In your case, it would probably mean upload files on the server, execute your commands there and send the file back on the client. Javascript and HTML 5 can certainly help here improve the overall user experience.
Move to Desktop
If you are doing some pretty intensive stuff on the client (processing multiple files, accessing resources that cannot be used from a browser, etc), you should consider regrouping this into a desktop app. You can even launch your app from a browser and sends some parameters to it by registering a Custom Protocol Handler, a la iTunes. Again, this is certainly not an easy replacement, as functionalities will often be spread out between the desktop app and the web app, which makes for some interesting scratch head moments trying to link the 2.
I have a program allowing script files to "compete" with each other in a games such as Tic Tac Toe .
The visualization is made in the console and looks something like this:
| XO |
| OX O|
| X |
- X is the winner! Meh..
Not very exciting.
I was thinking of making a Swing visualisation, but after seeing a presentation on the Raphaël JavaScript vector graphics library I decided that I'd be cool to make the visualization browser based, even though every thing will be running on the same computer.
Do I need a full fledged web server to accommodate for this? How does the JavaScript communicate with the Java program?
Building a Swing interface would be the most straightforward solution, but this would probably be the messiest one as well.
The web browser solution is probably the most satisfying if you already have a web server going, but has a lot of overhead to set up and properly understand. Then again, you have layers of different technology to play with and get confused in (java, JSP, HTML, javascript, css, etc).
These days, with HTML5 and available javascript libraries, the web interface is in my opinion the best choice for most interfaces, so you might as well set up your machine and have it available for the next project.
Any communication between the server (Java) and the browser will take place with a HTTP request from the browser.
This may happen in two ways:
a) By pressing a submit button on a browser HTML page and rendering a HTML page on the server as a response (usually through server side scripting like JSP, although you could generate the entire page through java code)
b) By using Ajax in javascript to make an asynchronous call to the server, which will respond with data that you can then interpret and render with javascript (probably the best solution for what you are trying to do). There are many ready javascript libraries to help you with this, including jQuery.
In method b, you would essentially be waiting on the server side for a post from the browser and then you would be responding with a page written in XML, json or even pure text. Your javascript code would then interpret the data and render it on the browser HTML page (which you will have loaded at the starting point for the application).
Do I need a full fledged web server to accommodate for this? How does the JavaScript communicate with the Java program?
If you're going to host the JavaScript and display in a browser, then yes, the browser would need to be able to request the data from the Java via an HTTP request. Although browsers can load data via file:/// URIs, it's (quite) awkward to handle those requests dynamically.
It's trivial to install a web server, though. Tomcat is easy to install, and there are several other options if you prefer, such as TJWS (no relation), Winstone, LiteWebServer, Jetty...
If you're forced to run Java for the game engine I would suggest using Jetty to give you the ability to service HTTP request from a browser. It's all embeddd in your application and there's no faffing with having to package your app as a WAR and deploy it everytime you make a change.
[edit]
Just read about Tiny Java Web Sever which could also be an alternative to Jetty if you need a smaller footprint.
Javascript can communicate with a Java applet on the page (at least in theory). A Java applet is going to throw up a warning when it loads, and requires that Java be installed on the machine.
Yes a webserver will be necessary. Javascript will probably run as part of an html form. If any Java side processing is required, then web server is necessary. Since it is not possible for the html/javascript to communicate with a standalone java program. But Why need a java server side program at all? Can the logic not be written in java script totally?
I'm trying to create a web application which will get input from system.
What this application should do is to listen what happens when some shell scripts are executing and reporting the status trough web.
An example :
I'm copying thousands of records with shell script, and while this is still executing I'd like pass the current status of the script to the web interface. From shell script side I could echo something like "The files are being copied please wait for it to finnish".
Using which programming language from shell side would be the easiest way to pass this to the web interface? I intended to use JSP/JAVA for web.
Is this even the right way to think about this? Every suggestion is welcome
EDIT
Would something like http://nodejs.org/ be useful for this?
I'd use a named pipe (FIFO) instead. You simply write your output to the pipe and let the application read it. I'm not sure if there is any other way to get a more live system than this.
I'd recommend Perl as the back-end.
EDIT:
named pipes are a special type of files on UNIX. The abbreviation FIFO stands for "First In First Out". On LINUX Journal you can find an interesting read about named pipes.
Perl is a very powerful scripting language with many ready-to-use modules which you can find on http://cpan.org. You can find some answers here on SO about how/where to start learning Perl.
The Web part of your application can easily read a file or a database, so you just need to make sure that your shell scripts are outputting something for your Java code to update.
For example, if you run your shell script like this
./myscript.sh > mylog.log
Then in your Java code (note that you should not have logic in your JSP), you can read in the file to determine the status of the update, and output the result to your JSP.
It would be better to read the data in from a database, but that would involve you changing your shell script to output the data to a database.
You could put shell script output to some storage on server. And use AJAX on the web page to poll the server and get updates from that storage to the page.
If you will decide to use JSF for web page creation I can recommend "a4j:poll" component from ajax2jsf library. It is very simple and straightforward. Very easy way to poll server from the web page.
Writing to log file would be the simplest solution. And in programming, simple often means good.
If you really need very fast/realtime system, you should probably make these logs a database.
As for language, use what you like best. They all do support SQLite, including bash.
If I understand your question correctly you want to display a web page on a client machine that reports the status of a long running task on a server machine. If that is the case then you need to focus on something called AJAX IMO.
For what it is worth the simplest and easiest to understand implementation of AJAX that I know of is Apache Wicket.
Although I've been programming for a few years I've only really dabbled in the web side of things, it's been more application based for computers up until now. I was wondering, in java for example, what library defined function or self defined function I would use to have a program launch a web browser to a certain site? Also as an extension to this how could I have it find a certain field in the website like a search box for instance (if it wasnt the current target of the cursor) and then populate it with a string and submit it to the server? (maybe this is a kind of find by ID scenario?!)
Also, is there a way to control whethere this is visible or not to the user. What I mean is, if I want to do something as a background task whilst the user carries on using the program, I will want the program to be submitting data to a webpage without the whole visual side of things that would interrupt the user?
This may be basic but like I say, I've never tried my hand at it so perhaps if someone could just provide some rough code outlines I'd really appreciate it.
Many thanks
I think Selenium might be what you are looking for.
Selenium allows you to start a Web browser, launch it to a certain website and interact with it. Also, there is a Java API (and a lot of other languages, by the way) allowing you to control the launched browser from a Java application.
There are some tweaking to do, but you can also launch Selenium in background, using a headless Web browser.
as i understand it you want to submit data to a server via the excisting webinterface?
in that case you need to find out how the URL for the request is build and then make a http-call using the corresponding URL
i advice reading this if it involves a POST submit