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ANNOUNCE: yesod-continuations
by Matt Brown 27 Nov '10

27 Nov '10

Hello all, I pushed a new package yesod-continuations to hackage. It allows you to register a handler for one time use (by the session that generated it) at a unique URL. I wrote it as an alternative to subsites for writing yesod widgets with "internal urls" (ajax widgets, for example). A demo (testcont.hs) is included in the source, and the master and continuation branches of my yesod-tailwidget repo compare the two approaches. Feedback is welcome. regards, -matt Hackage: http://hackage.haskell.org/package/yesod-continuations-0.1 GitHub: https://github.com/softmechanics/yesod-continuations yesod-tailwidget GitHub: https://github.com/softmechanics/yesod-tailwidget

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Yesod Form
by Dmitry Olshansky 25 Nov '10

25 Nov '10

Hello all, can I handle a form with more than one button in Yesod? In this case pair (button_name, button_value) is sent to the server on submit. Can I get it in some way? Best regards, Dmitry

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[Yesod?][Chromium?] file-echo.lhs on chromium
by いとうかつとし 24 Nov '10

24 Nov '10

Hi now, I runhaskell file-echo.lhs sample which in yesoddocs/yesod/tutorials, and check it on firefox and chromium browsers. On firefox, I confirm the program works good for varias type files. But, on chromium, i get error for same uploaded files which has no extensions like as README, TODO, LICENSE, ... when, I modify file-echo.lhs as below in order to get a log. --- postHomepage = do rr <- getRequest liftIO $ putStrLn "OK" -- Logging (_, files) <- liftIO $ requestBody rr fi <- maybe notFound return $ lookup "file" files liftIO $ do -- Logging putStrLn $ fileName fi putStrLn $ fileContentType fi return [(fileContentType fi, toContent $ fileContent fi)] --- On chromium, this handler function success to putStrLn "OK", but fail to putStrLn the others. I'd like to check HTTP headers, But i couldn't find my POST request in "Resources". The developer tool on chromium, my POST request is replaced by a request for 'chrome://chromewebdata/' Anyone knows this problem?

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Re: State in Yesod
by Michael Snoyman 24 Nov '10

24 Nov '10

On Wed, Nov 24, 2010 at 6:04 PM, Dmitry Olshansky <olshanskydr(a)gmail.com> wrote: > Hello all, > > can I save in Yesod on server-side some information between different > requests (State)? > I haven't found how to do this. Yes you can, but not by using a State monad. You basically have two choices: * Store inside the Yesod process, using something like an MVar or TVar. This will work fine, unless you are using multiple Yesod processes to serve requests (odds are, you aren't). * Store state in the database. But if you just want to store a small amount of data about the user, you can use the session, which stores the data encrypted in a cookie. I can give you better advice if I know what the purpose of this is. Michael

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IDEA: wai-vhost
by Michael Snoyman 23 Nov '10

23 Nov '10

Just thought I'd throw out an idea I've been bouncing around and see if anyone would be interested in either using or implementing it. Basically, it allows multiple WAI applications to be run as a single app and switch which app responds to a request based upon the Host, the same way virtual hosting works in web servers like nginx, Apache or lighttpd. I would imagine the type signature would look something like: vhost :: [(String, Application)] -> Application -> Application The first argument would be a list of applications and their respective virtual hosts (this would probably be better as a Map for performance, kind of irrelevant at this point). The second argument would be the default application to run when none of the vhosts match. This could even just be an app that always returns a 404. It returns a new application handles all of this transparently. I can see two immediate uses: * Instead of running a whole bunch of WAI fastcgi processes on a server, you could run just a single process that automatically deals out requests to the right app. This would save on memory usage, especially when your apps are all sharing the same Haskell libraries. * Instead of needing a dedicated web server like nginx to handle vhosting, you could use the Snap handler with this and be running a pure Haskell stack. Advantage would be easier maintenance, plus better performance from cutting out the middleman. At this point, it's just an idea. I don't think it's hard to implement, but I wouldn't mind some feedback first. And if someone else wants to take a crack at it, please speak up! I wouldn't mind having one less package to maintain. Michael

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[Yesod] failed : cabal install yesod-examples
by いとうかつとし 21 Nov '10

21 Nov '10

I'll install yesod-examples. But cabal install yesod-examples failed. Error Messages are here. ---- Linking dist/build/form/form ... yesod/tutorial/mkToForm.hs:11:7: Could not find module `MkToForm': Use -v to see a list of the files searched for. cabal: Error: some packages failed to install: yesod-examples-0.6.0 failed during the building phase. The exception was: ExitFailure 1 --- The mkToForm.hs's line 11 is 'import MkToForm'. You success to compile this?

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GHandler in forms
by Max Cantor 17 Nov '10

17 Nov '10

i didn't event realize that GHandler was in the GForm monad stack. knowing that, I would definitely like to use it. max

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Re: Amazon EC2 and haskell *Was: [web-devel] MochaHost for yesod applications?
by Max Cantor 15 Nov '10

15 Nov '10

Command line. I'll dig out the command later and send it to you. I found it digging around the ubuntu fora. Max On Nov 15, 2010, at 5:32 PM, Thomas Hartman wrote: > Great tip! > > How do you enable virtual memory? Linux command line thing or ec2 command thing or...? > > Cheers, thomas. > > On Mon, Nov 15, 2010 at 2:12 PM, Max Cantor <mxcantor(a)gmail.com> wrote: > The one thing you have to do on the micro instance is enable virtual memory, otherwise ld will crash (killed by signal 9 - very helpful) since GHC makes ld consume massive amounts of ram. > > Other than that, I haven't had a problem. > > Max > > On Nov 15, 2010, at 11:25 AM, Michael Snoyman wrote: > > > I've been planning on trying out their free micro instance. Does it > > provide enough power for you to actually compile things? And is email > > set up for you out-of-the-box? > > > > Michael > > > > On Mon, Nov 15, 2010 at 6:18 PM, Max Cantor <mxcantor(a)gmail.com> wrote: > >> I've started up with amazon EC2. They give you a free micro instance to get a feel for it. No arch, you're stuck with ubuntu, which seems to be alright. I have a small yesod based system running there. > >> > >> Pros: > >> - easy to massively scale up > >> - big trusted name > >> - data centers in the US (both coasts), APAC (singapore) and Europe. > >> - If a bunch of haskellers start using it, perhaps there will be better community AMIs (amazon machine image) for haskell to save us all a lot of setup. > >> > >> Cons: > >> - complete roll your own solution > >> - big trusted name (not the most personal service) > >> > >> > >> On Nov 14, 2010, at 3:43 PM, Nubis wrote: > >> > >>> I've decided to look for a cheap VPS where I can compile and run yesod applications using the latest and greatest haskell platform. > >>> I couldn't find any sane CGI/FastCGI shared host options. I'm even inclined towards developing some sort of heroku.com clone for apps running on WAI so we can solve the deployment issue for most people once and for all. > >>> > >>> I don't want to go with some obscure hosting I've never heard about and it has to be cheap (Argentinian budget). I've found mochahost has a pretty cheap VPS service with some cool OS choices. > >>> > >>> http://mochahost.com/vps.php > >>> > >>> Just thought the information may be useful for someone in the same situation as me, but I would like to hear if anyone has tried mochahost or even found an even more convenient choice for VPS. > >>> > >>> cheers! > >>> ----nubis :) > >>> _______________________________________________ > >>> web-devel mailing list > >>> web-devel(a)haskell.org > >>> http://www.haskell.org/mailman/listinfo/web-devel > >> > >> _______________________________________________ > >> web-devel mailing list > >> web-devel(a)haskell.org > >> http://www.haskell.org/mailman/listinfo/web-devel > >> > > _______________________________________________ > web-devel mailing list > web-devel(a)haskell.org > http://www.haskell.org/mailman/listinfo/web-devel > > > > -- > Thomas Hartman > Chief Technical Officer > MarketPsy Capital, LLC > 2400 Broadway, Suite 220 > Santa Monica, CA, USA > ______________________ > This e-mail message and any attachments may contain information that is confidential, proprietary or privileged, and is for the named person’s use only. No confidentiality or privilege is waived or lost by any mistransmission. If you are not the intended recipient or agent responsible for delivering it to the intended recipient, you are hereby notified that any dissemination, distribution, copying or other use of this message or its attachments is strictly prohibited. If you have received this message in error, please notify us immediately and destroy all copies of this message and attachments without disclosing the contents to anyone. Neither this message nor any information included herein constitute an offer to sell or the solicitation of an offer to buy any securities or investment product, or legal, tax, accounting, or investment advice. > > The fees and expenses charged in connection with the MarketPsy Long Short Fund LP ("the Investment") may be higher than the fees and expenses of other investment alternatives and may offset profits. No assurance can be given that the investment objective will be achieved or that an investor will receive a return of all of her/his investment. Investment results may vary substantially over any given time period. An investment in this Fund is speculative and involves a high degree of risk. The performance data represents the performance of the Fund as calculated by the management company. The performance figures include the reinvestment of any dividends and other earnings as appropriate. Past performance is not necessarily indicative of future results and there is always the possibility of loss.

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"Please Break Yesod" campaign
by Michael Snoyman 11 Nov '10

11 Nov '10

Hey all, I'd like to kick off the "Please Break Yesod" campaign[1] by drawing everyone's attention to Matt Brown's commit which converts the Route associated type from a type family to a data family. tl;dr: it avoids "not injective" compiler errors, and is overall good, fuzzy and made of unicorns. I'm even told that applying it may help regrow my hair. Anyway, if people would mind pulling his code and making sure it compiles, I'd appreciate it. The last time I tried to make that transition I stumbled upon a bug in GHC 6.12.1. I don't remember what the bug was, and I don't remember what the code was, so this is mostly just me acting paranoid for no good reason. Michael [1] http://docs.yesodweb.com/blog/please-break-yesod/ [2] https://github.com/softmechanics/yesod/commit/f3afdfeea2b2cac40051ce1ad795e…

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session management
by Christian Maeder 11 Nov '10

11 Nov '10

Hi, I've tried to understand session management looking at http://hackage.haskell.org/package/clientsession and http://hackage.haskell.org/packages/archive/yesod/0.6.1.1/doc/html/Yesod-Ha… I want a server to create a (unique) session-id, send it back to the client (how?) and handle requests from the client that supply this session-id somehow (how?). Thanks Christian P.S. "cabal install yesod-examples" finally failed with: Loading package ffi-1.0 ... linking ... done. Linking dist/build/form/form ... yesod/tutorial/mkToForm.hs:11:7: Could not find module `MkToForm': Use -v to see a list of the files searched for. cabal: Error: some packages failed to install: yesod-examples-0.6.0 failed during the building phase. The exception was: ExitFailure 1

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