Yesod Mform and hamlet

Question

Hi I am new to yesod and following the documentation to make a form. In the documentation the form template was created in .hs file itself. But I have a separate hamlet where I want to customize.

I want to access "fields" in my hamlet file. The expected type of 'generateFormPost' is (xml, Enctype) . Can anybody tell me what I should be returning from 'tableMform extra' . I think it should be in xml format. But I think I should not be using toWidget as in below example of documentation.

tableMform extra = do
    fields <- forM lis (\(w,h) -> mopt intField "this is not used" (Just h) )
    return (fields)      ---I know this line has the type error. Can anybody suggest how to deal with it

{-  
--I am referring this code from yesod website to make my form. In this it was using runFormGet, but I want use generateFormPost and moreover it was creating a widget which is used in displaying the website. I don't want to create the widget here but in my hamlet file where the 'fields' is accessed via interpolation.

personForm :: Html -> MForm Handler (FormResult Person, Widget)
personForm extra = do
    (nameRes, nameView) <- mreq textField "this is not used" Nothing
    (ageRes, ageView) <- mreq intField "neither is this" Nothing
    let personRes = Person <$> nameRes <*> ageRes
    let widget = do
            toWidget
                [lucius|
                    ##{fvId ageView} {
                        width: 3em;
                    }
                |]
            [whamlet|
                #{extra}
                <p>
                    Hello, my name is #
                    ^{fvInput nameView}
                    \ and I am #
                    ^{fvInput ageView}
                    \ years old. #
                    <input type=submit value="Introduce myself">
            |]
    return (personRes, widget)

-}

getHomeR :: Handler Html
getHomeR = defaultLayout $ do
    -- Generate the form to be displayed
    (fields, enctype) <- generateFormPost tableMform
    let (fires,fiview) = unzip fields
    $(widgetFile "layout")       
        |]

Please let me know if there is any misunderstanding. I have idea of how to get the form from the way done in the documentation, but I want to use a separate hamlet file, as I want to customize the look of the form.

Thanks Sai

EDIT: Sorry, I wasn't clear. I was trying to make a Mform where instead of creating the layout of the form in the ".hs" file , I wanted to give the layout in hamlet file. I have done it through http://pastebin.com/fwpZsKXy . But after doing that I could split it in to two files as I wanted. I have solved those errors. Thanks anyways

If you're getting type errors, it's a good idea to include the error messages in the question. I'm actually not certain what you're trying to achieve here, and the juxtaposition of your code with example code may be leading to confusion (at least on my part). — Michael Snoyman

Anirudh Anirudh · Accepted Answer · 2015-04-25T19:26:04

I got it. I was not clear of what "tableMform extra" has to return. I know that it has to return something of type [(FormResult a, xml)][1] . But then I was not sure what the type of "forM lis ((w,h) -> mopt intField (fromString w) (Just h) )" -- Line 2 was , So I followed what was done in documentation did it in the way it was done there.(without use of external widget file) .

After doing that I tried to do in the way I wanted to do i.e using a separate hamlet, julius and lucius files. http://pastebin.com/FgGph2CU . It worked !!

In summary I wasn't clear of the 'type' of "forM lis ((w,h) -> mopt intField (fromString w) (Just h) )" . Once I figured that out, it was easy.

Yesod Mform and hamlet

1 Answers