[web-devel] [Yesod] rendering different templates for different languages

[Michael Snoyman]

The other day I was speaking with a woman on the train. She was
telling me about her daughters. I wanted to ask her how old they are,
but I got the pluralization wrong and instead of saying "bnot kama"
(plural) I said "bat kama," (singular) to which she responded 36.

tl;dr: You can offend people just was well with pluralization issues
as with gender issues.

Michael

On Mon, Feb 21, 2011 at 8:40 AM, Max Cantor <mxcantor at gmail.com> wrote:
> Of course, you just pointed out one of the big difficulties with i18n.  I dont think you're wife would take kindly to you referring to her in the male gender.  so now, you need the person's gender too.  i18n is hard :(  the whole would should switch to esperanto.
>
> max
>
> On Feb 21, 2011, at 2:25 PM, Michael Snoyman wrote:
>
>> A proper i18n solution is high on my wish list right now, but I've
>> purposely avoided implementing one so far since I'd rather wait until
>> I think we have a good solution as opposed to implementing an
>> acceptable solution now. But let me share my ideas, it might help you
>> out here.
>>
>> In general, it's very uncommon that you need a completely separate set
>> of templates for each language. Your markup, classes, styles, and
>> logic will likely be identical for each language, and creating a
>> separate template for each will just result in a lot of pain in the
>> long run. Instead, you're likely better off having a single template
>> and just translating strings.
>>
>> I've blogged about this before[1]. My idea is to use a datatype for
>> your translatable strings, and then have a function that takes a
>> language and a value and returns the translated string. A simple
>> example:
>>
>>    data Strings = Hello | Person String Int
>>    toEnglish Hello = "Hello"
>>    toEnglish (Person name age) = name ++ " is " ++ show age ++ "
>> years old" -- obviously need to check if person is 1 year old and
>> correct
>>
>>    toHebrew Hello = "שלום"
>>    toHebrew (Person name age) = name ++ " הוא בן " ++ show age ++ " שנים"
>>
>> The nice thing about this approach is you have the full power of
>> Haskell to address typical translation issues, such as pluralization,
>> word order and gender matching. (As a counter example, at work, we use
>> XSLT for this, and then you get the full power of XSLT for solving the
>> problem ::cringe::.)
>>
>> You can then use the languages[2] function from Yesod to help you out:
>>
>>    getRenderString = chooseFunc `fmap` languages
>>       where
>>         chooseFunc [] = toEnglish -- default language
>>         chooseFunc ("en":_) = toEnglish
>>         chooseFunc ("he":_) = toHebrew
>>         chooseFunc (_:x) = chooseFunc x
>>
>> Then you can write a handler function like:
>>
>> getPersonR name age = do
>>    render <- getRenderString
>>    defaultLayout [$hamlet|
>> <h1>#{render Hello}
>> <p>#{render $ Person name age}
>> |]
>>
>> Which will work for English and Hebrew just fine. Ideally, I would
>> like to add support to Hamlet for this directly, involving a String
>> rendering function similar to the URL rendering function already in
>> place. But for the moment, this should work.
>>
>> I'd love to hear peoples opinions about this.
>>
>> Michael
>>
>> [1] http://docs.yesodweb.com/blog/i18n-in-haskell
>> [2] http://hackage.haskell.org/packages/archive/yesod-core/0.7.0.1/doc/html/Yesod-Request.html#v:languages
>>
>> On Sun, Feb 20, 2011 at 11:19 PM, Dmitry Kurochkin
>> <dmitry.kurochkin at gmail.com> wrote:
>>> Hi all.
>>>
>>> I want a handler to render different templates for different languages.
>>> I have getCurrentLanguage function and now I try to do something like:
>>>
>>>    getRootR = do
>>>        currentLanguage <- getCurrentLanguage
>>>        defaultLayout $ do
>>>            addWidget $(widgetFile $ currentLanguage ++ "/homepage")
>>>
>>> This results in:
>>>
>>>    GHC stage restriction: `currentLanguage'
>>>      is used in a top-level splice or annotation,
>>>      and must be imported, not defined locally
>>>
>>> This makes sense to me, because TH is calculated at compile time. I
>>> would like to hear ideas how to work around this restriction. Perhaps
>>> there is an existing solution in Yesod?
>>>
>>> At the moment, the best I could think of is smth like this:
>>>
>>>    getRootR = do
>>>        currentLanguage <- getCurrentLanguage
>>>        defaultLayout $ do
>>>            case currentLanguage of
>>>                "en" -> addWidget $(widgetFile  "en/homepage")
>>>                ... and so on for each language ...
>>>
>>> Obviously, this is not a solution taking in account that there are many
>>> languages and many handlers.
>>>
>>> I was considering creating a global (template file name -> rendered
>>> template) map. But I am not sure this is really feasible.
>>>
>>> Regards,
>>>  Dmitry
>>>
>>> _______________________________________________
>>> web-devel mailing list
>>> web-devel at haskell.org
>>> http://www.haskell.org/mailman/listinfo/web-devel
>>>
>>
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>
>