7 ms·

Happstack 0.4: A scalable framework for developing web applications in Haskell

29 points by dons 17y ago

aufreak3 17y ago
Incredibly happy to see this. This could tip the balance in favour of Haskell as a viable platform for web development, given it is as or better performing than something like Go.
nearestneighbor 17y ago
I'm curious, which web sites are currently running on Haskell?
- dons 17y ago
  http://patch-tag.com/ http://patch-tag.com/ is a github for darcs, that happens to be running in happstack. http://gitit.net/ http://gitit.net/ is a wiki based on gitit running in happstack. DB used happs for analytic sites for day traders ( http://cufp.galois.com/2008/abstracts.html#PolakowJeff http://cufp.galois.com/2008/abstracts.html#PolakowJeff ), and notable, JanRain (the OpenID company) used Haskell on the server side for some components.
smanek 17y ago
I know HAppS advocated an approach of using static HTML with Javascript for content/dom stuff. From http://happs.org/ http://happs.org/: HAppS does not come with a server-side templating system. We prefer the pattern of developing static web pages and using AJAX to populate them with dynamic content. Does Happstack take the same approach? Can anyone comment on how this architecture affects googlebot and other spiders?
- dons 17y ago
  See the release notes in the above link. happstack comes with: * HTML/XML/etc templating via HStringTemplate, HSP, or Text.XHtml with server-side templating, happstack is not happs, and emphasies pragmatism.
- baguasquirrel 17y ago
  You can pretty much use any old approach you'd like with Happstack. I am using it right now and it is very modular. You could conceivably use the Text.HTML module to make your own pages in the functional style. You can use HStringTemplate a la psp and php. Or you can do the fun, bloated and awful web 2.0 thing and write an ass-ton of javascript to do everything in the ajax-y fashion, and just use happstack to serve up json. A similar situation holds for the MACID data store. It looked ok to me, but I wanted to play with some distributed DBs instead (e.g. Mongo and Couch), and it works just fine there too. The important thing is that if you understand how HTTP works, how requests are served up, etc., then you can pretty much hit the ground running with happstack, without having to set up Apache and learn cgi or set up Tomcat and figure out how to get the default permissions on Ubuntu to work. So in that regard, it seems much closer to RoR than the traditional approach.
- Dunearhp 17y ago
  I've been using HStringTemplate on top of happstack quite happily. REST would be fairly easy to achieve using this approach. I would venture to suggest that most people would find it easier to adapt happstack directly to their needs than trying to use happs at this point in time.
kunley 17y ago
Really scalable? http://tutorial.happstack.com/tutorial/macid-limits http://tutorial.happstack.com/tutorial/macid-limits "A realistic way to use Happstack with macid is to write an alpha version of an application using macid (no database), and then add some other type of persistent hard drive storage (probably database) outside of macid only if it becomes necessary. This raises the question: if you are eventually going to have to put in a database back end, why use macid at all? The -- perhaps slightly depressing answer -- is that you probably won't have to put in a database back end, because your app won't be so successful that this is required." Now this is ridiculous. That's the way you guys are going to convince people to use Haskell for reald world apps? Don't get me wrong, I'd like to see Haskell winning in territories occupied by other languages, but this looks just like another piece of Haskell code written for the sake of being written in Haskell.
- dons 17y ago
  Happstack's been around for a long time, and has been used in a number of production systems (including at Deutsche Bank). They're certainly trying some interesting things. > convince people to use Haskell for reald world apps? The project is not the language. If you want regular old approaches to web apps, there's libraries for that ( http://hackage.haskell.org/packages/archive/pkg-list.html#cat:web http://hackage.haskell.org/packages/archive/pkg-list.html#ca... ) in Haskell. But there's also happstack if you like their approach. The vision all along was that the vast majority of web apps could be written in a MACID style -- they're not huge sites -- so make that as easy as possible.
  - kunley 17y ago
    Yeah I should have said Happstack not the language, but it isn't my point. Point is that the tutorial section I cited discouraged serious use of the stuff it's supposed to promote.
  - chriseidhof 17y ago
    Are they really using the macid system? I don't believe that. Happstack is nice, but I wouldn't trust my data with Happstack's storage system.

29 points by dons 17y ago

Incredibly happy to see this. This could tip the balance in favour of Haskell as a viable platform for web development, given it is as or better performing than something like Go.

nearestneighbor 17y ago

I'm curious, which web sites are currently running on Haskell?

dons 17y ago
http://patch-tag.com/ http://patch-tag.com/ is a github for darcs, that happens to be running in happstack. http://gitit.net/ http://gitit.net/ is a wiki based on gitit running in happstack. DB used happs for analytic sites for day traders ( http://cufp.galois.com/2008/abstracts.html#PolakowJeff http://cufp.galois.com/2008/abstracts.html#PolakowJeff ), and notable, JanRain (the OpenID company) used Haskell on the server side for some components.

smanek 17y ago

I know HAppS advocated an approach of using static HTML with Javascript for content/dom stuff. From http://happs.org/ http://happs.org/: HAppS does not come with a server-side templating system. We prefer the pattern of developing static web pages and using AJAX to populate them with dynamic content. Does Happstack take the same approach? Can anyone comment on how this architecture affects googlebot and other spiders?

dons 17y ago
See the release notes in the above link. happstack comes with: * HTML/XML/etc templating via HStringTemplate, HSP, or Text.XHtml with server-side templating, happstack is not happs, and emphasies pragmatism.
baguasquirrel 17y ago
You can pretty much use any old approach you'd like with Happstack. I am using it right now and it is very modular. You could conceivably use the Text.HTML module to make your own pages in the functional style. You can use HStringTemplate a la psp and php. Or you can do the fun, bloated and awful web 2.0 thing and write an ass-ton of javascript to do everything in the ajax-y fashion, and just use happstack to serve up json. A similar situation holds for the MACID data store. It looked ok to me, but I wanted to play with some distributed DBs instead (e.g. Mongo and Couch), and it works just fine there too. The important thing is that if you understand how HTTP works, how requests are served up, etc., then you can pretty much hit the ground running with happstack, without having to set up Apache and learn cgi or set up Tomcat and figure out how to get the default permissions on Ubuntu to work. So in that regard, it seems much closer to RoR than the traditional approach.
Dunearhp 17y ago
I've been using HStringTemplate on top of happstack quite happily. REST would be fairly easy to achieve using this approach. I would venture to suggest that most people would find it easier to adapt happstack directly to their needs than trying to use happs at this point in time.

kunley 17y ago

Really scalable? http://tutorial.happstack.com/tutorial/macid-limits http://tutorial.happstack.com/tutorial/macid-limits "A realistic way to use Happstack with macid is to write an alpha version of an application using macid (no database), and then add some other type of persistent hard drive storage (probably database) outside of macid only if it becomes necessary. This raises the question: if you are eventually going to have to put in a database back end, why use macid at all? The -- perhaps slightly depressing answer -- is that you probably won't have to put in a database back end, because your app won't be so successful that this is required." Now this is ridiculous. That's the way you guys are going to convince people to use Haskell for reald world apps? Don't get me wrong, I'd like to see Haskell winning in territories occupied by other languages, but this looks just like another piece of Haskell code written for the sake of being written in Haskell.

dons 17y ago
Happstack's been around for a long time, and has been used in a number of production systems (including at Deutsche Bank). They're certainly trying some interesting things. > convince people to use Haskell for reald world apps? The project is not the language. If you want regular old approaches to web apps, there's libraries for that ( http://hackage.haskell.org/packages/archive/pkg-list.html#cat:web http://hackage.haskell.org/packages/archive/pkg-list.html#ca... ) in Haskell. But there's also happstack if you like their approach. The vision all along was that the vast majority of web apps could be written in a MACID style -- they're not huge sites -- so make that as easy as possible.
- kunley 17y ago
  Yeah I should have said Happstack not the language, but it isn't my point. Point is that the tutorial section I cited discouraged serious use of the stuff it's supposed to promote.
- chriseidhof 17y ago
  Are they really using the macid system? I don't believe that. Happstack is nice, but I wouldn't trust my data with Happstack's storage system.