Add syntactic sugar for onBeforeInput & onBeforeInputCapture

generator/src/main/scala/slinky/generator/Generator.scala

@@ -14,6 +14,7 @@ object Generator {
 
     val eventToSynthetic = Map[String, String => String](
       "EventHandler" -> (t => s"slinky.core.SyntheticEvent[$t, org.scalajs.dom.Event]"),
+      "InputEventHandler" -> (t => s"slinky.web.SyntheticInputEvent[$t]"),
       "ClipboardEventHandler" -> (t => s"slinky.web.SyntheticClipboardEvent[$t]"),
       "CompositionEventHandler" -> (t => s"slinky.web.SyntheticCompositionEvent[$t]"),
       "KeyboardEventHandler" -> (t => s"slinky.web.SyntheticKeyboardEvent[$t]"),

web/html.json

@@ -2214,6 +2214,18 @@
       "hasCaptureVariant" : true
     },
 
+    // Input Events
+    {
+      "attributeName" : "onBeforeInput",
+      "attributeType" : "InputEventHandler",
+      "docLines" : [
+        ""
+      ],
+      "compatibleTags" : null,
+      "withDash" : false,
+      "hasCaptureVariant" : true
+    },
+
     // Keyboard Events
     {
       "attributeName" : "onKeyDown",

web/src/main/scala/slinky/web/SyntheticInputEvent.scala

@@ -0,0 +1,11 @@
+package slinky.web
+
+import slinky.core.SyntheticEvent
+import scala.scalajs.js
+import org.scalajs.dom.InputEvent
+
+//https://react.dev/reference/react-dom/components/common#inputevent-handler
+@js.native
+trait SyntheticInputEvent[+TargetType] extends SyntheticEvent[TargetType, InputEvent] {
+  val data: String = js.native
+}