LibWeb: Implement 'no-validate state' concept

Author: https://github.com/edvwib 🔰
Commit: 8ca956e6f1
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/4592
Reviewed-by: https://github.com/tcl3

Libraries/LibWeb/HTML/FormAssociatedElement.cpp

@@ -350,6 +350,27 @@ bool FormAssociatedElement::satisfies_its_constraints() const
         suffering_from_being_missing() || suffering_from_a_type_mismatch() || suffering_from_a_pattern_mismatch() || suffering_from_being_too_long() || suffering_from_being_too_short() || suffering_from_an_underflow() || suffering_from_an_overflow() || suffering_from_a_step_mismatch() || suffering_from_bad_input() || suffering_from_a_custom_error());
 }
 
+// https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#concept-fs-novalidate
+bool FormAssociatedElement::novalidate_state() const
+{
+    // The no-validate state of an element is true if the element is a submit button ...
+    if (!is_submit_button())
+        return false;
+
+    // ..., and the element's formnovalidate attribute is present, ...
+    auto const& html_element = form_associated_element_to_html_element();
+    if (html_element.has_attribute(HTML::AttributeNames::formnovalidate))
+        return true;
+
+    // ... or if the element's form owner's novalidate attribute is present, ...
+    auto* form = this->form();
+    if (form && form->has_attribute(HTML::AttributeNames::novalidate))
+        return true;
+
+    // ... and false otherwise.
+    return false;
+}
+
 // https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#limiting-user-input-length%3A-the-maxlength-attribute%3Asuffering-from-being-too-long
 bool FormAssociatedElement::suffering_from_being_too_long() const
 {