Adds a function for getting types from a data transfer object

src/DOM/HTML/Event/DragEvent/DataTransfer.js

@@ -3,3 +3,7 @@
 exports.files = function (dataTransfer) {
   return dataTransfer.files;
 };
+
+exports.types = function (dataTransfer) {
+  return dataTransfer.types;
+};

src/DOM/HTML/Event/DragEvent/DataTransfer.purs

@@ -1,4 +1,8 @@
-module DOM.HTML.Event.DragEvent.DataTransfer where
+module DOM.HTML.Event.DragEvent.DataTransfer
+  ( DataTransfer
+  , files
+  , types
+  ) where
 
 import DOM.File.Types (FileList)
 
@@ -7,3 +11,7 @@ foreign import data DataTransfer :: *
 -- | Contains a list of all the local files available on the data transfer.
 -- | Empty if the drag operation doesn't involve dragging files.
 foreign import files :: DataTransfer -> FileList
+
+-- | Returns an array of data formats used in the drag operation.
+-- | If the drag operation included no data, then the array is empty.
+foreign import types :: DataTransfer -> Array String