Newtype wrappers for some JavaScript values

1 files changed, 38 insertions, 0 deletions

diff --git a/src/JavaScript/Element.hs b/src/JavaScript/Element.hs
new file mode 100644
index 0000000..2eac8f2
--- /dev/null
+++ b/src/JavaScript/Element.hs
@@ -0,0 +1,38 @@
+module JavaScript.Element (
+    Element, IsElement(..),
+    getElementById,
+    documentQuerySelector,
+    querySelector,
+) where
+
+import JavaScript.Event
+import JavaScript.Val
+
+
+newtype Element = Element JSVal
+    deriving (ToJSVal, FromJSVal)
+
+class IsElement a where
+    toElement :: a -> Element
+
+instance IsElement Element where
+    toElement = id
+
+instance IsEventTarget Element where
+    toEventTarget = fromJSValUnchecked . toJSVal
+
+
+getElementById :: String -> IO (Maybe Element)
+getElementById = fmap nullToNothing . js_document_getElementById . toJSString
+foreign import javascript unsafe "document.getElementById($1)"
+    js_document_getElementById :: JSString -> IO JSVal
+
+documentQuerySelector :: String -> IO (Maybe Element)
+documentQuerySelector = fmap nullToNothing . js_document_querySelector . toJSString
+foreign import javascript unsafe "document.querySelector($1)"
+    js_document_querySelector :: JSString -> IO JSVal
+
+querySelector :: IsElement e => String -> e -> IO (Maybe Element)
+querySelector sel e = nullToNothing <$> js_querySelector (toJSVal $ toElement e) (toJSString sel)
+foreign import javascript unsafe "$1.querySelector($2)"
+    js_querySelector :: JSVal -> JSString -> IO JSVal