Add support for HTML form attribute.

Author: matthughes

core/src/main/scala/japgolly/scalajs/react/vdom/HtmlAttrs.scala

@@ -363,6 +363,11 @@ trait HtmlAttrs {
     * elements.
     */
   final def `for` = VdomAttr("htmlFor")
+    
+  /**
+    * Allows association of an input to a non-ancestoral form.
+    */
+  final def formId = VdomAttr("form")
 
   final def formAction = VdomAttr("formAction")
 

doc/changelog/1.4.0.md

@@ -22,6 +22,7 @@
   * Components now resolve to `VdomElement`s without the need for explicit imports.
     Typically, this means no more errors when creating router config without importing vdom.
     ([#509](https://github.com/japgolly/scalajs-react/issues/509))
+  * Add `formId` HTML attribute for associating an input element with a non-ancestoral form.
 
 * Add `AsyncCallback` which is like a pure version of Scala's `Future` and JS's `Promise`.
   Asynchronous code can be composed using `for`-comprehensions as if it's synchronous,