CustomFormLayout

Custom form layout

Use monadic forms to get full control over the form layout. Here's a simple example. The html argument is used to add extra fields to the form, for POST forms this is a hidden nonce field to prevent cross-site request forgery.

data D1 = D1 { d1f1::Text
             , d1f2::(Maybe Text)
             , d1f3::Integer
             } deriving (Eq, Show)

form :: RenderMessage master FormMessage =>
        Maybe D1 -> Html ->
        Form sub master (FormResult D1, GWidget sub master ())
form d = \html -> do
  (r1, v1) <- mreq textField "field1" (d1f1 <$> d)
  (r2, v2) <- mopt textField "field2" (d1f2 <$> d)
  (r3, v3) <- mreq intField  "field3" (d1f3 <$> d)
  let vs = [v1, v2, v3]
  return (D1 <$> r1 <*> r2 <*> r3, [whamlet|
    #{html}
    $forall v <- vs
      <div>
        <div .label>#{fvLabel v}
        $maybe tt <- fvTooltip v
          <div .tooltip>#{tt}
        <div .input>^{fvInput v}
        $maybe err <- fvErrors v
          <div .error>#{err}
  |])