Slashdot Mirror
When a CGI Script is the Most Elegant Solution
An anonymous reader writes "Writing local Web applications can be quick, easy, and efficient for solving specific Intranet problems. Learn why a Web browser is sometimes a better interface than a GUI application and why experienced Web developers find themselves struggling to learn a GUI toolkit, and descover that a simple CGI script would serve their needs perfectly well, if not better."
When everything else is not.
Quick web scripts are way easier than developing an application if only for the fact that you don't need to figure out how to use networking in whatever language you'd be working in. Plus, you don't need to "distribute" the application once it's done, and you don't need to provide updates to every user on your network who's using it: update your script, update the application.
Plus, developers think in program logic, not in program design. A web script let's the developer write their output in HTML, then go back in later and add some CSS for presentation once they've got the program actually working. I say, it's a good way to do things.
Not to mention that a lot of web scripting languages are easier to use than full-blown application languages, and there are many packages that let you attach native GUIs to web scripts. There isn't a compelling argument not to go that route if your application a) uses networking, and b) is distributed over an intranet.
A lot of people are replacing client-server apps with browser based apps, with zero install hassles - which this particular example doesn't really have. But learning to build html apps in CGI mode is easier than re-learning event loops for GTK land (even in perl).
Of course, debugging in-browser apps is getting easier with firebug and other developer oriented firefox bits. Now, whether the app is built using perl-CGI, mod_perl, php, ruby on rails, even servlets doesn't matter - the UI can actually work very well. For instance my sudoku, in fact looks better in HTML than if I (let me repeat, if *I*) had done it with GTK or MFC.
And CGI still hasn't lost its edge totally. There are places when you *have* to use CGI to do what you want. I ran into one case when I couldn't use php when I wanted to server pushes on a live connection. Instead of firing multiple requests to the server, I hold the connection and push data when it comes available - sort of stateful connections reinvented for HTTP. Which has definite promise when you're building mashups, which fetch data from elsewhere without cross-user leakage (heh, if he can hijack TCP, I don't know what...) - flockr for instance uses such a script in the backend to feed it data (except I'll be an idiot to post a live CGI script to slashdot).
CGI ain't quite dead yet ...
Quidquid latine dictum sit, altum videtur
One of the issues that concerns me is what essentially amounts to hijacking of my processing resources. One example is animated ads. It takes CPU power to continually flip a large ad's frames; that's *my* CPU power. So I don't let flash or animated GIFs run unless I make an exception. Same thing applies, for instance, to the difference between slashdot and digg. Slashdot provides a static page. I can load it, and the fact that it is loaded costs me nothing in particular. If I flip away from the browser, it doesn't chew CPU time. But if I load a digg page, my CPU is pegged for a while, especially with large pages, because digg is bloated, slow-as-hell pigware that uses *my* CPU to display and organize its content. Guess how much time I spend there. :)
As I generally have other things going in the background, I don't take kindly to profligate use of my resources; animations, pigware, etc. I keep my eyes open, and I tend to spend time on places that more resemble slashdot than digg in this regard. I *will* bite if the site offers something that overcomes my urge to keep my cycles for myself, but that is a conscious value judgement, not an accident.
Generally speaking, there's another advantage for sites that produce HTML and CGI forms, and do not depend upon the user's computing environment, and that is broad compatibility. If you stick to the basics, then the broadest set of browsers will function with your "stuff." No Java, no PDF, no flash... just the basics. You can make beautiful, functional websites (assuming you've the art skills) with the basics. I see no need for more; the value is in the content, and it isn't like you can't make a good presentation. The first thing I think when I run into a morass of Java, etc., is "incompetent."
But that's just me. :)
I've fallen off your lawn, and I can't get up.
None of those are problems with web apps, they're problems with the decisions the companies made in developing said web apps.
Real programming basically died in the mid 1990s.
I don't understand either the problem space, or the solution. I've read the article twice -- though it is apparent by most of the comments that people have not read the article.
It sounds like the author is recommending a single instance web server application running on a local machine that uses a file store instead of a database and CGI as the programming interface. (In other words, this is NOT an intranet application for multiple users!) Doesn't sound that simple at all. In order to do this, you must:
- Know at least one programming language for CGI.
- Know HTML including forms, postback and session.
- Understand the limitations of web browser UI elements. (There are many.)
- Install and maintain a webserver on your local machine.
- Build a robust file store interface. (Even loading / saving / parsing XML files with backups takes time...)
- Install and maintain permissions for the file store.
- And more...
Sounds like all of the disadvantages of the web with none of the advantages.
Why would you not use PERL and CSV IN/OUT files for simple (or complex) command line processing -- and if you needed a really simple UI, then Excel with Visual Basic. (This isn't easy, but it's a lot less technology to learn and maintain.) Anything more complex: Java, the free version of Microsoft VS or xcode. Anything worth doing is worth doing well.
"even with mod_perl"? as opposed to what? mod_perl is the most flexible web server technology available on *nix, balancing good performance with a good set of functionality (who can beat CPAN?) it's faster and more scalable than Tomcat, and PHP is simply a joke. about the only true downside is that it's a total memory hog.
perl CGI, however, is crap as you said
God Fucking Damnit
You're just jealous because our stuff actually is used by a lot of people, whereas your toaster-controller, written in C, with a user-interface noone understands only got five downloads from Tucows. And one of them was your cat jumping up on your keyboard.
Are doomed to reinvent them, poorly, in a web browser.
The premise of the article is that a local application written to target a local server with web browser client is better, but then goes on to say essentially 'ok, here are all the pain in the ass things to overcome when trying to scale it down to a single user compared to typical web server environments'. In his article, he is trading one perceived pain in the ass set of things for another. The unstated stuff is you are requiring the unmentioned user to first have a webserver and CGI environment set up correctly before even beginning to run your app (since the aim is to be standalone on a box, the user's system is the server). He mentions some shortcuts you can take by assuming some network security things and no DB, but in the end the shortcuts are still more work than simple GUI apps for the equivalent task.
As to his fear of GUI toolkits, it's actually mostly silly. He sums it up by saying web browsers don't make you deal with 'resize events, window expose events, or menu events', but the truth is for a GUI application of the complexity he speaks of, GUI toolkits largely don't *make* you, they *let* you. If your application is as simple as what he prescribes, you can ignore that whole functionality of the toolkit. Sure you have to connect events to widgets of interest (i.e. buttons), but you have to do the exact same thing on webapps, but with different wording. If your application has some reason to start messing with the sort of stuff he fears dealing with and is implemented in a browser, a whole lot of pain is in store for you with obscure, platform specific javascript aplenty. Similarly, he mentions file opening/saving, and font management, but again, the toolkit usually has user-wide settings you can ignore the existence of just like a browser for font and style, and evoking the Toolkit standard filebrowser is usually exceedingly simple (along the lines of filename=Chooser() (not a specific language/toolkit)).
I have dealt with quite a few 'webapp-for-everything' people, generally they make web apps with an exceptionally clunky interface that responds poorly (I actually dislike Gmail's interface, but Zimbra was impressive, but still sluggish). If I find myself using it frequently and I can find out what it is frontending (usually a database for general apps, imap for mail, etc), then I write a quick GUI application or use a standard standalone app to do the same thing. I end up with a smoother interface that lets me be more productive, and often things run faster (webapp deployments are frequently the bottleneck, the backend could service far more than the webapp can push through for whatever reason). Whenever I do that and someone glances me interfacing with a system notoriously annoying in interface, they always want my application. Again, good Webapps can be on par with GUI apps, but for all the reasons the guy mentions, webapp developers mostly think implementing everything as simple forms is the way to go and that sucks for a lot of usage. GUI apps of course can be written piss-poor as well, but the typical GUI toolkit primitives are richer than simple HTML forms.
The only potential thing depending on how the app manages data and how it could be useful is the issue of scaling out/up. With a standalone GUI app, the barrier to running it remotely and having all your data in one place is higher than webapps (if running it remotely, must have X/RDP/VNC client installed on your random client which is less likely than a browser, if just having the data remote, still have to get the data accessible via some means and your client must have your software). This is a hard thing to define concretely, but the implementor should be able to make this determination fairly easily.
XML is like violence. If it doesn't solve the problem, use more.
Their main function is to think of the "from the ... dept." line. Doing a spellcheck or other mundane editing tasks would distract them from that.
...and then you would be right to say,
if (you == inHouseProgrammer)
"Well you cocksuckers should have told me all this shit up front so I didn't waste my weekend writing a useless web app. If you want it fixed, do it yourself"
else if (you == consultant && you == chargingTimeAndMaterials)
"I'll be happy to add those new requirements for you, but I'm afraid that's going to impact the schedule."
else if (you == consultant && you == chargingFixedFee)
"Thanks for the feedback, bit I'm afraid we will have to address those new requirements in a follow-on contract."