LibWeb: Implement HTMLFormElement::get_submittable_elements()

This implements a convenience method on HTMLFormElement to retrieve a
list in tree order of submittable elements associated with the form
element.

1 files changed, 27 insertions, 0 deletions

diff --git a/Userland/Libraries/LibWeb/HTML/HTMLFormElement.cpp b/Userland/Libraries/LibWeb/HTML/HTMLFormElement.cpp
index a40da14126..c4310bb0b0 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLFormElement.cpp
+++ b/Userland/Libraries/LibWeb/HTML/HTMLFormElement.cpp
@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
+ * Copyright (c) 2023, Kenneth Myhra <kennethmyhra@serenityos.org>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -247,4 +248,30 @@ unsigned HTMLFormElement::length() const
     return elements()->length();
 }
 
+// https://html.spec.whatwg.org/multipage/forms.html#category-submit
+ErrorOr<Vector<JS::NonnullGCPtr<DOM::Element>>> HTMLFormElement::get_submittable_elements()
+{
+    Vector<JS::NonnullGCPtr<DOM::Element>> submittable_elements = {};
+    for (size_t i = 0; i < elements()->length(); i++) {
+        auto* element = elements()->item(i);
+        TRY(populate_vector_with_submittable_elements_in_tree_order(*element, submittable_elements));
+    }
+    return submittable_elements;
+}
+
+ErrorOr<void> HTMLFormElement::populate_vector_with_submittable_elements_in_tree_order(JS::NonnullGCPtr<DOM::Element> element, Vector<JS::NonnullGCPtr<DOM::Element>>& elements)
+{
+    if (auto* form_associated_element = dynamic_cast<HTML::FormAssociatedElement*>(element.ptr())) {
+        if (form_associated_element->is_submittable())
+            TRY(elements.try_append(element));
+    }
+
+    for (size_t i = 0; i < element->children()->length(); i++) {
+        auto* child = element->children()->item(i);
+        TRY(populate_vector_with_submittable_elements_in_tree_order(*child, elements));
+    }
+
+    return {};
+}
+
 }