May 2011 - web-devel - Haskell.org

I18n in Yesod
by Sven Koschnicke (GFXpro) 10 May '11

10 May '11

Hello, I just tested the I18n support in Yesod, looks very promising! Altough I noticed a small annoyance: There's often the case that you want to provide translations for the names of your models, i.e. Books. You will have a model named Book. When you then try to create a translation "Book" you get an ambiguous occurrence error. I'm sure it is possible to solve it by using namespaces but I'm just starting haskell so I'm not sure how to implement it, also I think the framework should handle this case. Sven

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Database.Persistent
by Jeremy Hughes 10 May '11

10 May '11

Hi all, Is Database.Persistent lazy wrt reading fields? I need to iterate over entities containing both small and large fields. I do not need to use the large fields in this instance, and so would rather they were not read from the database. Cheers, Jeremy -- enjoying exploring yesod

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Template Haskell intricacies with mkPersist
by Patrick Palka 09 May '11

09 May '11

Hey, I've attached a file that fails to compile, resulting in a "not in scope: getHomeR" error message. The culprit seems to be the mkPersist TH splice, which, when ocurring before the getHomeR view, causes it to not be seen by GHC when it parses the mkYesod splice. Moving the mkPersist splice to occur after the getHomeR view will alleviate this problem, but then one can't use the data constructors that mkPersist generates within the getHomeR view. Moving the mkPersist splice into a seperate module and importing that works perfectly fine, however. Can anyone clarify what is going on?

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I can't install yesod
by Александр Лазарев 09 May '11

09 May '11

Haskell Platform 2011.2.0.1, Win XP SP2. I've try install yesod by in cygwin window *cabal install yesod* but take $ cabal install yesod Resolving dependencies... cabal.exe: cannot configure tls-extra-0.2.2. It requires certificate >=0.8.1 && <0.9 For the dependency on certificate >=0.8.1 && <0.9 there are these packages: certificate-0.8.1. However none of them are available. certificate-0.8.1 was excluded because certificate-0.7.0 was selected instead certificate-0.8.1 was excluded because http-enumerator-0.6.4.1 requires certificate ==0.7.* The same result I take on ubuntu 10.10 with Haskell Platform 2010. What I can in this circumstancies

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when we switch to aeson, perhaps a QQ for JSON..
by Max Cantor 09 May '11

09 May '11

I know that the kickass yesod team is looking to change the json library to aeson. One nice feature would be quasi-quoting for the library like in the following library. hackage.haskell.org/packages/archive/text-json-qq/0.2.0/doc/html/Text-JSON-…

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Naming Yesod templates
by Greg Weber 09 May '11

09 May '11

Hi web-devel, Yesod has generalized hamlet-style templates a fair amount now so that hamlet-style interpolation can be quickly added to any file. With this in mind, we don't want to add a new Shakespearean name for every possible file format. The standard we would like to follow is that if we actually create a new format (hamlet or cassius), then we give it a special name. However, if the template is just a pass-through (Julius), then it does not deserve a new name. We have moved in this direction with coffeescript (pass-through), just referring to it as coffee. We would like to come up with a way to refer to hamlet-style templates. I have used the term "hamlet family of templates". Shakespeare is a somewhat natural fit. We would then call the Cofffeescript templates "Shakespeare Coffeescript". However, a more descriptive name might be nice. A short description of hamlet-style templates is: compile-time evaluated, type-safe (we insert specific types, not just string), convenient (automatically uses variables that are in scope), template languages. Any input on possible names is welcome! Also, just a heads up about that we are planning on making aeson a yesod-core dependency (please complain now if you take issue). This is because we want to move orphan ToJavascript instances will be moved into Julius/Coffee where they belong We can make Julius/Coffee a separate package so that hamlet does not have an aeson dependency, but this package will still be a core dependency, and thus will create an aeson dependency in yesod-core. Greg Weber

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Sample code for Persistent.MongoDB connections?
by Max Cantor 09 May '11

09 May '11

Has anyone been able to use the MongoDB backend in a real project yet? If so, would you mind sharing the code for setting up connections and the YesodPersist instance? I tried to follow the example for the Test in the backend code itself but that involved a lot of strange class instances and ended up breaking some other things in Yesod. If no one's done this yet, I'll work through it on me own, just looking for a shortcut ;) max

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Yesod: Regarding Widgets and addJulius
by Mathew de Detrich 07 May '11

07 May '11

I seem to have come across a problem regarding javascript and using widgets (im using Yesod 0.7.3). I add javascript to widgets normally with addJulius, however when they get added into the head of the website, the tags that enclose the javascript code are <script> Instead of <script type="text/javascript"> I also think this is the reason why the javascript is not executing on my website Also unless I am missing something would it be possible to implement a function like addJulius but instead of adding it to the script to the <head> html page, the javascript gets concatenated into a .js file (which is returned by some route). Thanks

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Yesod. Strange behavior. Persistent. Templating
by Anton Cheshkov 06 May '11

06 May '11

Hi Michael, i have found strange behavior. All worked fine. i change the one line in the *config/model *file from *Category* * name Text* to *Category* * name Text Desc* * * * * * * After that all application was broke . Seems like all 'exports' from * Model.hs* was lost. If i change back to '*name Text*' all works fine again. Thanks. * * -- Best regards, Cheshkov Anton Phone: +7 909 005 18 82 Skype: cheshkov_anton

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Embedding hamlet that was binded in hamlet
by Aur Saraf 05 May '11

05 May '11

I guess this hamlet code shouldn't work currently: $maybe link <- mlink ^link^ I think that's too bad, as it is very useful sometimes. Maybe we should make it work? Is it too hard? Cheers, Aur

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