1 files changed, 59 insertions, 0 deletions
diff --git a/client/src/Util/Reflex.hs b/client/src/Util/Reflex.hs
new file mode 100644
index 0000000..aa5cebb
--- /dev/null
+++ b/client/src/Util/Reflex.hs
@@ -0,0 +1,59 @@
+module Util.Reflex
+  ( visibleIfDyn
+  , visibleIfEvent
+  , divVisibleIf
+  , divClassVisibleIf
+  , flatten
+  , flattenTuple
+  , getBody
+  ) where
+
+import qualified Data.Map                 as M
+import           Data.Text                (Text)
+import qualified GHCJS.DOM                as Dom
+import qualified GHCJS.DOM.Document       as Document
+import qualified GHCJS.DOM.HTMLCollection as HTMLCollection
+import           GHCJS.DOM.Types          (Element)
+import           Reflex.Dom               (Dynamic, Event, MonadWidget)
+import qualified Reflex.Dom               as R
+
+visibleIfDyn :: forall t m a. MonadWidget t m => Dynamic t Bool -> m a -> m a -> m (Event t a)
+visibleIfDyn cond empty content =
+  R.dyn $ R.ffor cond $ \case
+    True -> content
+    False -> empty
+
+visibleIfEvent :: forall t m a. MonadWidget t m => Event t Bool -> m a -> m a -> m (Dynamic t a)
+visibleIfEvent cond empty content =
+  R.widgetHold empty $
+    R.ffor cond $ \case
+      True -> content
+      False -> empty
+
+divVisibleIf :: forall t m a. MonadWidget t m => Dynamic t Bool -> m a -> m a
+divVisibleIf cond content = divClassVisibleIf cond "" content
+
+divClassVisibleIf :: forall t m a. MonadWidget t m => Dynamic t Bool -> Text -> m a -> m a
+divClassVisibleIf cond className content =
+  R.elDynAttr
+    "div"
+    (fmap (\c -> (M.singleton "class" className) `M.union` if c then M.empty else M.singleton "style" "display:none") cond)
+    content
+
+flatten :: forall t m a. MonadWidget t m => Event t (Event t a) -> m (Event t a)
+flatten e = do
+  dyn <- R.holdDyn R.never e
+  return $ R.switchDyn dyn
+
+flattenTuple
+  :: forall t m a b. MonadWidget t m
+  => Event t (Event t a, Event t b)
+  -> m (Event t a, Event t b)
+flattenTuple e = (,) <$> (flatten $ fmap fst e) <*> (flatten $ fmap snd e)
+
+getBody :: forall t m. MonadWidget t m => m Element
+getBody = do
+  document <- Dom.currentDocumentUnchecked
+  nodelist <- Document.getElementsByTagName document ("body" :: String)
+  Just body <- nodelist `HTMLCollection.item` 0
+  return body