July 2011 - web-devel

[ Yesod ][ Newbie ][ Widgets ] Ways of adding app manu
by Kamil Ciemniewski 08 Jul '11

08 Jul '11

Hi all, I'm trying to add to my "admin layout" main menu in Yesod. Normally - doing it in Rails - I would create a partial or helper and then use it in my layout file. But here in Yesod - the concept of widgets seems somewhat fereign to me. I don't quite get them. In my Handler.Admin module I define: adminLayout :: GWidget MyApp MyApp () -> GHandler MyApp MyApp RepHtml adminLayout widget = do mmsg <- getMessage mroute <- getCurrentRoute pc <- widgetToPageContent $ do widget hamletToRepHtml $(hamletFile "admin/admin-layout") then I define my widget ( all in the same file ): mainMenu :: Widget () mainMenu = addWidget $(widgetFile "admin/_menu") And finally in "admin/admin-layout.hamlet" I'm trying to render my menu: ... ^{mainMenu} ... All without a luck.. Compiler yells at me strange ( to me ) things: Handler/Admin.hs:31:27: Couldn't match expected type `GGWidget MyApp (GHandler MyApp MyApp) ()' with actual type `(url0 -> [(T.Text, T.Text)] -> T.Text) -> blaze-html-0.4.1.1:Text.Blaze.Internal.Html' Expected type: Widget () Actual type: hamlet-0.8.1:Text.Hamlet.Quasi.Hamlet url0 In the return type of a call of `pageBody' In the first argument of `hamlet-0.8.1:Text.Hamlet.Quasi.fromHamletValue', namely `pageBody pc' Which doesn't occur when I'm not trying to render "mainMenu" widget. What am I doing wrong? And are there any informations about using widgets anywhere? ( because I haven't found many.. )? Best regards Kamil Ciemniewski

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Haskell code highlighting
by Michael Snoyman 08 Jul '11

08 Jul '11

Hi all, I want to add (back) Haskell code highlighting to the Yesod site, and decided to take a poll for what package people recommend. A quick browsing of Hackage reveals the following possibilities: * http://hackage.haskell.org/package/colorize-haskell * http://hackage.haskell.org/package/highlighter * http://hackage.haskell.org/package/highlighting-kate * http://hackage.haskell.org/package/hscolour What do people recommend? And what are people's preferred CSS file for this? Thanks, Michael

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[yesod] Messages / i18n question: how to handle "xx-xx" languages
by Markus Barenhoff 08 Jul '11

08 Jul '11

Hi! I'am using mkMessage to create the i18n stuff for a project. I've created a en.msg and a de.msg and everything is running smoothly and I can use the message consts in my hamlet template with _{}. But I'am a little bit unsure whats the best practise to handle the language parameters like 'de-de' or 'en-us'. The Message framework does not seem to handle those cases by using en.msg for en-us if en-us.msg is not found. But copying the message files also seems not a good option. Putting a "take 2" version of the language to the _LANG cookie var works, but needs a reload to become active... Any suggestions / best practice advices? Regards Markus

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[yesod] how convert Content to String or Text
by Dmitriy Nikitinskiy 07 Jul '11

07 Jul '11

Hello All. I have following code: getMyRoute :: String -> Handler RepXml getMyRoute r = liftM RepXml $ hamletToContent [hamlet|<node |] getOtherRoute :: Handler () getOtherRoute = do (RepXml mycontent) <- getMyRoute "something" -- how write mycontent to file here? -- let str = ???? or str <- ???? -- liftIO $ writeFile "myfile.xml" str return () How convert Yesod.Content.Content to String or Text? Thanks. Dmitriy

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[yesod] using presistance in sub sites
by Markus Barenhoff 06 Jul '11

06 Jul '11

Hi there! I'm a bit confused on how to use persistence in a sub site... I've written this here, which fails to compile: https://gist.github.com/1058863 Is it possible at all to define persistence functionality on subsite level and then use the masters runDB ? Whats best practice here? I've seen yesod-auth let implement the persistance related stuff over a type class in the master ... But I'd like to keep that stuff with the subsite... Ideas, comments anyone? Thanks Markus

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[xml-types] Help needed: Constructing XML documents
by Aristid Breitkreuz 06 Jul '11

06 Jul '11

Hi, I want to construct a Document object from scratch. Using only xml-types, this can be somewhat cumbersome. Is there a better way? Maybe a package? Aristid

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Flex with happstack backend
by Mister Asafe Ribeiro 05 Jul '11

05 Jul '11

Someone have points in mixing Flex with Haskel?? Perhaps I would be able to use Happstack as backend using JSON to talk to Flex ?

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Happstack stack overflow
by Mister Asafe Ribeiro 03 Jul '11

03 Jul '11

Hi, I have a handler for a post request that uses CouchDB to save a new book: newBookHandler :: ServerPart Response newBookHandler = do methodM POST decodeBody myPolicy title <- look "Title" description <- look "Description" type' <- lookRead "Type" permission <- lookRead "Permission" let author = "Asafe" liftIO $ createBook (Book title type' author description permission) ok $ toResponse ( Template.books "Your new book was just created ! Give it some love now") create is defined like that: createBook book = runCouchDB' $ newDoc db' $ toJSON book However when I perform the post request I get: Server error : Stack overflow. All works fine if I comment the line of createBook. I must be missing something because I was not able to use macid neither...

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