It's something totally new for me, and since it seems to be something trivial, I can't find any response with our beloved friend ggle...
My question is : I have to create a webapp that can work if the client have nothing on his computer but a browser. My question is : is it possible to include to my project an external library (here I want to use PCL (Point Cloud library), a C++ library), and make it works even if the client have nothing installed? If I use QtWebKit for example, will I be able to create this kind of webapp?
Thanks a lot, and sorry for the (maybe) stupid question, I never did web dev before, it's my first time. ...
Have a nice day!
Wow, that question is as broad as the day is long, but here goes (you don't give too much about your background so I apologise if I am going too basic).
A web browser is just a piece of software that knows how to process HTML, CSS and Javascript passed over HTTP from a TCP socket.
So, on a most basic level, to get something to work in a browser all you need is to write a program that listens on a TCP socket and passes headers and HTML in the body of the response as per the HTTP protocol.
So, leaving aside the socket part, your method may look something like this:
std::cout << "<h1>Hello, world!</h1>" << std::endl;
In fact, the vast majority of the original dynamic web sites worked just like this: they were just C programs that just happened to produce HTML as output in the old days (cgi-bin).
The main issue with this approach is it's very tedious and time consuming to write code to that level of detail to generate HTML, especially when you factor in CSS and JavaScript.
This is one of the key reasons that most web applications these days are implemented in Java, .Net, Ruby, PHP etc as there is a wealth of fully-featured, stable and mature frameworks for web development that take the grunt work out of creating dynamic web sites (and C/C++ is much rarer).
However there are a couple of good frameworks out there for C++ if that is definitely the language you want to use.
Wikipedia has a limited section on C++ frameworks but it covers the 2 I would suggest investigating (CppCMS and Wt):
https://en.wikipedia.org/wiki/Comparison_of_web_frameworks#C.2B.2B
Of these, I've only had direct experience of CppCMS but I can recommend it - it's approach is idiomatic C++ (to my eyes at least, but I must confess I am more often a Java web developer than C++)
Also, there is quite a useful if slightly dogmatic SO discussion on this thread that may be relevant:
How popular is C++ for making websites/web applications?
Related
Is there a relatively easy way to display the output of a C++ program on a webpage? And I don't mean manually, in other words, you see it on a webpage as it runs not as in I make a code tag and write it in myself.
EDIT: Just so everybody can get this clear I am going to post this up here. I am NOT trying to make a webpage in C++. Please excuse me if this sounds spiteful or anything but I am getting a lot of answers relating to that.
Step one, get yourself a server-side language. Be that PHP, ASP, Python, Ruby, whatever. Get it set up so you can serve it.
Step two, find your language's exec equivalent. Practically all of them have them. It'll let you run a command as if it were from the command line, usually with arguments and capture the output. Here's PHP's:
http://php.net/manual/en/function.exec.php
Of course, if you're passing user-input as arguments, sanitise!
I've just seen that you accepted Scott's answer. I usually wouldn't chase up a SO thread so persistently but I fear you're about to make a mistake that you'll come to regret down the line. Giving direct access to your program and its own built-in server is a terrible idea for two reasons:
You waste a day implementing this built-in server and then getting it to persist and testing it
More importantly, you've just opened up another attack vector into your server. When it comes to security, keep it simple.
You're far better having your C++ app running behind another (mature) server side language as all the work is done for you and it can filter the input to keep things safe.
You could write a CGI app in C++, or you could use an existing web server language to execute the command and send the output to the client.
You want to use Witty.
Wt (pronounced 'witty') is a C++
library for developing interactive web
applications.
The API is widget-centric and similar
to desktop GUI APIs. To the developer,
it offers complete abstraction of any
web-specific implementation details,
including event handling, graphics
support, graceful degradation (or
progressive enhancement), and pretty
URLs.
Unlike many page-based frameworks, Wt
was designed for creating stateful
applications that are at the same time
highly interactive (leveraging
techinques such as AJAX to their
fullest) and accessible (supporting
plain HTML browsers), using automatic
graceful degradation or progressive
enhancement.
The library comes with an application
server that acts as a stand-alone web
server or integrates through FastCGI
with other web servers.
I am not sure this is what you are looking for but you may want CGI You may want to look at this SO question, C++ may not be the best language for what you want to do.
based off the questions you posted Writing a web app like what you want is no simple task. What I would recommend is use some other library (this is one i found with a quick google) to get a web console on your server and give the user it is running under execute deny permissions on every folder except the folder you have your app installed.
This is still is a risky method if you don't set up the security correctly but it is the easiest solution without digging around too much on existing libraries to just have the application interactive.
EDIT --
The "Best" solution is learn AJAX and have your program post its own pages with it but like I said, it will not be easy.
It sounds like you want something like a telnet session embedded in a webpage. A quick google turns up many Java telnet apps, though I'm not qualified to evaluate which would be most ideal to embed in html.
You would set up the login script on the host machine to run your c++ app and the user would interact with it through the shell window. Note though that this will only work for pure command line apps. If you want to use a GUI app in this way, then you should look into remote desktop software or VNC.
It may be worth looking into Adobe's "Alchemy" project on Adobe Labs
This may help you with what you're trying to achieve.
:)
Are you looking for something like what codepad.org does? I believe they explain how they did it here.
There is a library called C++ Server Pages - Poco. I used it for one of my college project, its pretty good. There is also good documentation to get started with, u can find it here http://pocoproject.org/docs/
I have a few years experience programming c++ and a little less then that using Qt. I built a data mining software using Qt and I want to make it available online. Unfortunately, I know close to nothing about web programming. Firstly, how easy or hard is this to do and what is the best way to go about it?
Supposing I am looking to hire someone to make me a secure, long-term, extensible, website for an online software service, what skill set should I be looking for?
Edit:
I want to make my question a little more specific:
How can I take a bunch of working c++ functions and port the code so I can run it server side on a website?
Once this is done, would it be easy to make changes to the c++ code and have the algorithm automatically update on the site?
What technologies would be involved? Are there any cloud computing platforms that would be good for something like this?
#Niklaos-what does it mean to build a library and how does one do that?
You might want to have a look at Wt[1]. Its a C++ web framework which is programmed more or less like a desktop GUI application. One of the use cases quoted is to bring legacy apps into the web.
[1] http://www.webtoolkit.eu
Port the functions to Java, easily done from C++, you can even find some tools to help - don't trust them implicitly but they could provide a boost.
See longer answer below.
Wrap them in a web application, and deploy them on Google App-Engine.
Java version of a library would be a jar file.
If you really want to be able to update the algorithm implementation dynamically, then you could implement them in Groovy, and upload changes through a form on your webapp, either as files or as a big text block, need to consider version control.
The effort/skillset involved to perform the task depends on how your wrote your code. If it is in a self-contained library, and has a clean (re-entrant, thread safe) API, you could probably hire a web developer (html/php/asp etc) to write the UI interface to the library for a relatively small cost. The skills required would be dependant on the technologies you wanted to use. For Windows development I would suggest C#/ASP. The applicant would require knowledge of interfacing with native libraries from a managed language. This is assuming that you dont mind the costs of Windows deployment for your application.
On the otherhand, if the library is complex or needs to be re-written to support the extensibility you are looking for, asking here will not get you much.
BTW: here is a great article on Marshalling if you chose to implement using C#/ASP
http://msdn.microsoft.com/en-us/magazine/cc164193.aspx
First, DO NOT USE PHP :D
I used it for some projects (the last one with symphony framework) and i almost shoot my self !
If you are very familiar with C++, ASP .NET could be a good solution because if you like C++ you are going to love C#.
Any ways, I personally use Ruby on Rails for 6 months now and I LOVE IT. I won't write you a book here but the framework is pure gold !
The only problem is that Ruby is a very special language. You will probably be a bit lost a the beginning. But as every one you will learn to love it.
But that was only for the server side. Indeed, there 3 technologies you won't be able to avoid if you want to start to develop web applications.
HTML, CSS and JavaScript are presents every where. This is why i'm thinking you should start by HTML and CSS then JavaScript (with jQuery).
When you've got some basics with these 3 technologies you should be able to choose the server side language.
But you've got to tell you one thing, it's not going to be easy !
PS : Ruby on Rails uses HAML and SASS. These 2 languages replaces HTML and CSS you should have a look at them quickly because they are awesome.
Background:
I have a new site in the design phase and am considering using ColdFusion. The Server is currently set-up with ColdFusion and Python (done for me).
It is my choice on what to use and ColdFusion seems intriguing with the tag concept. Having developed sites in PHP and Python the idea of using a new tool seems fun but I want to make sure it is as easy to use as my other two choices with things like URL beautification and scalability.
Are there any common problems with using ColdFusion in regards to scalability and speed of development?
My other choice is to use Python with WebPy or Django.
ColdFusion 9 with a good framework like Sean Cornfeld's FW/1 has plenty of performance and all the functionality of any modern web server development language. It has some great integration features like exchange server support and excel / pdf support out of the box.
Like all tools it may or may not be the right one for you but the gotchas in terms of scalability will usually be with your code, rarely the platform.
Liberally use memcached or the built in ehache in CF9, be smart about your data access strategy, intelligently chunk returned data and you will be fine performance wise.
My approach with CF lately involves using jQuery extensively for client side logic and using CF for the initial page setup and ajax calls to fill tables. That dramatically cuts down on CF specific code and forces nice logic separation. Plus it cuts the dependency on any one platform (aside from the excellent jQuery library).
To specifically answer your question, if you read the [coldfusion] tags here you will see questions are rarely on speed or scalability, it scales fine. A lot of the questions seem to be on places where CF is a fairly thin layer on another tool like Apache Axis (web services) and ExtJs (cfajax) - neither of which you need to use. You will probably need mod-rewrite or IIS rewrite to hide .cfm
Since you have both ColdFusion and Python available to you already, I would carefully consider exactly what it is you're trying to accomplish.
Do you need a gradual learning curve, newbie-friendly language (easy for someone who knows HTML to learn), great documentation, and lots of features that make normally difficult tasks easy? That sounds like a job for ColdFusion.
That said, once you get the basics of ColdFusion down, it's easy to transition into an Object Oriented approach (as others have noted, there are a plethora of MVC frameworks available: FW/1, ColdBox, Fusebox, Model-Glue, Mach-ii, Lightfront, and the list goes on...), and there are also dependency management (DI/IoC) frameworks (my favorite of which is ColdSpring, modeled after Java's Spring framework), and the ability to do Aspect-Oriented Programming, as well. Lastly, there are also several ORM frameworks (Transfer, Reactor, and DataFaucet, if you're using CF8 or earlier, or add Hibernate to the list in CF9+).
ColdFusion also plays nicely with just about everything else out there. It can load and use .Net assemblies, provides native access to Java classes, and makes creating and/or consuming web services (particularly SOAP, but REST is possible) a piece of cake. (I think it even does com/corba, if you feel like using tech from 1991...)
Unfortunately, I've got no experience with Python, so I can't speak to its strengths. Perhaps a Python developer can shed some light there.
As for url rewrting, (again, as others have noted) that's not really done in the language (though you can fudge it); to get a really nice looking URL you really need either mod_rewrite (which can be done without .htaccess, instead the rules would go into your Apache VHosts config file), or with one of the IIS URL Rewriting products.
The "fudging" I alluded to would be a url like: http://example.com/index.cfm/section/action/?search=foo -- the ".cfm" is in the URL so that the request gets handed from the web server (Apache/IIS) to the Application Server (ColdFusion). To get rid of the ".cfm" in the URL, you really do have to use a URL rewriting tool; there's no way around it.
From two years working with CF, for me the biggest gotchas are:
If you're mainly coding using tags (rather than CFScript) and formatting for readability, be prepared for your output to be filled with whitespace. Unlike other scripting languages, the whitespace between statements are actually sent to the client - so if you're looping over something 100 times and outputting the result, all the linebreaks and tabs in the loop source code will appear 100 times. There are ways around this but it's been a while - I'm sure someone on SO has asked the question before, so a quick search will give you your solution.
Related to the whitespace problem, if you're writing a script to be used with AJAX or Flash and you're trying to send xml; even a single space before the DTD can break some of the more fussy parsing engines (jQuery used to fall over like this - I don't know if it still does and flash was a nightmare). When I first did this I spent hours trying to figure out why what looked like well formed XML was causing my script to die.
The later versions aren't so bad, but I was also working on legacy systems where even quite basic functionality was lacking. Quite often you'll find you need to go hunting for a COM or Java library to do the job for you. Again, though, this is in the earlier versions.
CFAJAX was a heavy, cumbersome beast last time I checked - so don't bother, roll your own.
Other than that, I found CF to be a fun language to work with - it has its idiosyncracies like everything else, but by and large it was mostly headache free and fast to work with.
Hope this helps :)
Cheers
Iain
EDIT: Oh, and for reasons best known to Adobe, if you're running the trial version you'll get a lovely fat HTML comment before all of your output - regardless of whether or not you're actually outputting HTML. And yes, because the comment appears before your DTD, be prepared for some browsers (not looking at any one in particular!) to render it like crap. Again - perhaps they've rethought this in the new version...
EDIT#2: You also mentioned URL Rewriting - where I used to work we did this all the time - no problems. If you're running on Apache, use mod_rewrite, if you're running on IIS buy ISAPI Rewrite 3.
do yourself the favor and check out the CFWheels project. it has the url rewriting support and routes that you're looking for. also as a full stack mvc framework, it comes with it's own orm.
It's been a few years, so my information may be a little out of date, but in my experience:
Pros:
Coldfusion is easy to learn, and quick to get something up and running end-to-end.
Cons:
As with many server-side scripting languages, there is no real separation between persistence logic, business logic, and presentation. All of these are typically interwoven throughout a typical Coldfusion source file. This can mean a lot more work if you want to make changes to the database schema of a mature application, for example.
There are some disciplines that can be followed to make things a little more maintainable; "Fusebox" was one. There may be others.
I am familiar with both Python and C++ as a programmer. I was thinking of writing my own simple web application and I wanted to know which language would be more appropriate for server-side web development.
Some things I'm looking for:
It has to be intuitive. I recognize that Wt exists and it follows the model of Qt. The one thing I hate about Qt is that they encourage strange syntax through obfuscated means (e.g. the "public slots:" idiom). If I'm going to write C++, I need it to be standard, recognizable, clean code. No fancy shmancy silliness that Qt provides.
The less non-C++ or Python code I have to write, the better. The thing about Django (Python web framework) is that it requires you pretty much write the HTML by hand. I think it would be great if HTML forms took more of a wxWidgets approach. Wt is close to this but follows the Qt model instead of wxWidgets.
I'm typically writing video games with C++ and I have no experience in web development. I want to write a nice web site for many reasons. I want it to be a learning experience, I want it to be fun, and I want to easily be able to concentrate on "fun stuff" (e.g. less boilerplate, more meat of the app).
Any tips for a newbie web developer? I'm guessing web app frameworks are the way to go, but it's just a matter of picking one.
I would go with Wt because:
You already know C++
It has a nice layout system, so you don't need to know lots of HTML
It is very well written and a pleasure to code in
Your deployed apps will handle 50 times the load of the python app on less hardware (from experience with pylons apps, 10,000 times the load of a plone app :P)
It has all the libraries that the guy in the first question says it doesn't and more
In built development webserver
Templating language
ORM
unit testing help
open-id and user+password authentication
A brilliant widget library
Web 2.0 isn't an after thought; it wasn't designed on a Request+Response model like all the python frameworks (as far as I know), but on an event driven interactive model.
It uses WebSockets if available
Falls back to normal ajax gracefully if not
Falls back to http for browsers like linx
It is more like coding a gui app than a web app, which is probably what you're used to
It is statically typed and therefore less error prone. Does def delete(id): take an int or a string ?
The unit tests (on my apps at least) take 10-100 times less time than my python app unit tests to run (including the compile time)
It has a strong and friendly community. All my email list posts are answered in 0-3 days.
If you'd like to avoid writing HTML, you could try GWT. However, in my experience, using an intermediate framework to generate HTML and ECMAScript never works anywhere near as well as hand-writing the pages.
[edit] nikow mentions in the comments that Pyjamas is a port of GWT to Python.
Regarding the language, if given the choice between C++ and Python I would pick Python 100% of the time. Even ignoring the obvious difference in abstraction between those languages, Python simply has more useful libraries than C++. You don't have to write your own development-oriented web server -- Django comes with one. You don't need to write a custom template library -- Python has Genshi. Django comes with a capable ORM layer, or for even more control you can use SQLAlchemy. It's barely a contest.
Django is good point to start web development it is great framework
If you look for C++ take a look on CppCMS, it is much more close to Django, it is not like Wt that mimics Qt.
In any case, it is really depends on your needs. C++ can be used for embedded or high performance web applications, but for medium range web sites Django would be better. (and I'm developer of CppCMS)
I think you better go firt python in your case, meanwhile you can extend cppCMS functionalities and write your own framework arround it.
wt was a good idea design, but somehow not that suitable.
If you are exploring Python frameworks (based on the excepted answer I think you are) I think you really owe it to yourself to check out CherryPy. When you write CherryPy apps, you really are just writing Python apps. The framework gets out of your way in a real hurry. Your free to choose your own templating, ORM (if you choose to use ORM), etc. Seriously, take 10 or 20 minutes and give it a look.
The only reason you might want to use C++ over Python is when speed is paramount.
If this is going to be your first web-app, you'll probably be ok with just Python, and your development speed will be orders of magnitude better than with CPP.
Django's templating language is far from powerless, to me it actually seems very pythonic. You actually can write pure python in a template(although this is generally not recommended).
Even better, it's possible to replace Django's templating system with the one you like.
My personal favourite language for this is HAML.
Here's some data on this:
Is there a HAML implementation for use with Python and Django
Having looked several ones, like django, pylos, web2py, wt. My recommendation is web2py. It's a python version of "ruby on rails" and easy to learn.
I want to create a web application that runs with very little RAM and I think C++ can help me achieve that.
Now, many people say C++ is unsuited for web development because:
there is no easy string manipulation
is an unsafe language (overflows, etc)
long change / build / test cycles
etc.
But I'm sure the C++ community have found ways to alleviate all those (maybe not the compile time) however since I'm not a regular so it is hard for me to put a value on what I find in Google.
So I'm asking for some guidance. I would appreciate if you share what works, what tools/libs are current and alive. What strategies can help with web dev in C++? FastCGI or embedded server (Asio / POCO / Pion / etc.)? How do you address security concerns?
Thanks a lot for any help
Have you looked at http://www.tntnet.org/. They have created a... well let me cut and paste from their website:
Tntnet is a modular, multithreaded,
high performance webapplicationserver
for C++. To create webapplications
Tntnet has a template-language called
ecpp similar to php, jsp or mason,
where you can embed c++-code inside a
html-page to generate active content.
The ecpp-files are precompiled to
c++-classes called components and
compiled and linked into a shared
library. This process is done at
compiletime.
I've used it and it has quite a small overhead plus it has screamingly fast dynamic page generation. Makes PHP, Ruby etc snails in comparison because with tntnet you are running compiled C/C++ code.
There's the Wt Project. It uses a paradigm similar to Qt's signals/slots.
There is nothing wrong with trying to build a web app in C++. It's actually a lot of fun. What you need is a:
Templating system
A CGI lib
A database API wrapper, most likely, to avoid dealing with something like the low-level MySQL API
A logger
ATL Server is a library of C++ classes that allow developers to build internet based applications.
ATL Server. It's open source too! And of course there is always ISAPI. Ah, the bad old days. :)
In your other question you mention that your embedded system is openwrt. As this router firmware already comes with a embedded web server (for it's administration UI), why don't you use that for you app as well?
Our web app backend is in C++ via CGI and we use Clearsilver templates along with the HDF that comes with it.
Give us some more hints about what you're trying to do.
You can write a good old-fashioned cgi program in C++ easily enough, and run it with FastCGI. We used to do that all the time.
You could write a C++ program embedding a lightweight HTTP server as well.
Both of them are much bigger PITAs than using something like perl or ruby.
So for why C++?
Update
Okay, got it. The main thing about FastCGI is that it avoids a fork-exec to run your CGI program, but it is a little bit different API. That's good, but you still have the problem of handling the HTTP stuff.
There are, however, several very lightweight HTTP servers, like Cherokee and Lighttpd. In similar situations (building web interfaces for appliances) I've seen people use one of these and run their C/C++ programs under them as a CGI. Lighttpd in particular seems to concentrate on making CGI-like stuff fast and efficient.
Another update. I just had cgicc pointed out to me: http://www.gnu.org/software/cgicc/
That might solve some problems.
You can try Cutelyst a C++11 built with Qt, with one of the best positions on TechEmpower Benchmarks.
Even though it requires Qt 5.6+ a full CMS (CMlyst) uses around 6MB of RAM while serving around 3000 requests per seconds on a single core.
And for your string manipulation issue QString is just an amazing class for that.