January 2013 - web-devel

ANNOUNCE: MFlow 0.2
by Alberto G. Corona 18 Jan '13

18 Jan '13

Hello. haskellers and, specially, web developpers. This is the second version of MFlow, a deep-first effort in the development of a platform for web applications at the higher level, by including as much haskell magic as possible. It is at the same time experimental and intended to be used in industry. I believe that haskell will not have its chance in the Web if it does not bring unique advantages and challenging paradigms beyond speed and type safety. Deep-first means that the effort is more in the addition higher level features rather than in being complete and bug free, with the conviction that feedback from real usage at the highest level is the best guide for development. Rather than to mimic other platforms in other languages, MFlow is as Haskell'ish as possible, and introduces new approaches like statefulness, event sourcing, back-execution, composable, active, self contained widgets and persistent STM. All of them collaborate to create a high level environment for web programming. This release adds bidings for WAI, blaze-html, stateful AJAX, active widgets, requirements, content management, multilanguage and URLs to pages inside stateful procedures. The package: [http://hackage.haskell.org/package/MFlow The entry in my blog, with the announcement and the philosophy behind http://haskell-web.blogspot.com.es/2013/01/announce-mflow-02.html The same, in other words: http://haskell-web.blogspot.com.es/2012/12/on-spirit-of-mflow-anatomy-of-wi… An online example, with some links that explain the new features. http://81.169.134.95:8081 Stateful, but virtually stateless, thanks to event sourcing http://haskell-web.blogspot.com/2013/01/stateful-but-stateless-at-last-than… Example of use of active widgets http://haskell-web.blogspot.com.es/2013/01/now-example-of-use-of-active-wid… Bug tracker https://github.com/agocorona/MFlow/issues Source repository git clone http://github.com/agocorona/MFlow Feedback is welcomed warmly Alberto.

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Happstack events and timeouts
by Asafe Ribeiro 17 Jan '13

17 Jan '13

I've a timeline that is automatically updated when a user I follow post something new. I've already done the client-side code and some of the server-side as well. But I have a couple of issues that I cant figure out how to with happstack: How do I set a timeout for the request? I don't want to have more than one request for a same user. How can I stop all other request when I get a new one for a given user ?

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ANN: Hakyll 4
by Jasper Van der Jeugt 16 Jan '13

16 Jan '13

After a few weeks of beta status [1], I've now released version 4.0 of the Hakyll static site generator library. I'm really glad with this release, as from what I've found and heard, it makes many things a lot easier. # Main changes - The important `Compiler` type has been changed from `Arrow` to `Monad`: this makes it much easier to write custom compilers, as most Haskellers are more familiar with monads. - The template stays superficially the same, but it has grown much more powerful and flexible underneath. - Early and fast access to metadata makes things such as tags and pagination much easier. - All items (images, css...) can now have metadata associated. Metadata can no longer be manipulated, and this immutability should reduce the number of encountered bugs. - A `check` command has been added. This allows you to check that all internal (or external) links are still alive. # Installation, migration In order to install Hakyll 4, grab it from Hackage: cabal update cabal install hakyll Here are some useful links: - Website: <http://jaspervdj.be/hakyll/> - Tutorial index: <http://jaspervdj.be/hakyll/tutorials.html> - Migration guide: <http://jaspervdj.be/hakyll/tutorials/hakyll-3-to-hakyll4-migration-guide.ht…> All feedback is welcome as always. [1]: https://groups.google.com/d/topic/hakyll/eRKWz8bVB0w/discussion Peace, Jasper

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