LibWeb: Use right interface for custom SVG and MathML elements

The DOM spec gets overridden by both the SVG2 and MathML core specs in that unknown elements should not inherit DOM::Element, but SVG::SVGElement and MathML::MathMLElement respectively.
AtkinsSJ · Oct 31, 2024 · 76e638b · 76e638b
1 parent 84fe8d6
commit 76e638b
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Showing 3 changed files with 34 additions and 17 deletions.
diff --git a/Tests/LibWeb/Text/expected/DOM/Document-createElementNS-custom.txt b/Tests/LibWeb/Text/expected/DOM/Document-createElementNS-custom.txt
@@ -0,0 +1,3 @@
+Element nodeName: FOO namespaceURI: http://www.w3.org/1999/xhtml __proto__: [object HTMLUnknownElement]
+Element nodeName: foo namespaceURI: http://www.w3.org/2000/svg __proto__: [object SVGElement]
+Element nodeName: foo namespaceURI: http://www.w3.org/1998/Math/MathML __proto__: [object MathMLElement]
diff --git a/Tests/LibWeb/Text/input/DOM/Document-createElementNS-custom.html b/Tests/LibWeb/Text/input/DOM/Document-createElementNS-custom.html
@@ -0,0 +1,13 @@
+<!doctype html>
+<script src="../include.js"></script>
+<script>
+    test(() => {
+        const printElement = (element) => {
+            println(`Element nodeName: ${element.nodeName} namespaceURI: ${element.namespaceURI} __proto__: ${element.__proto__}`);
+        };
+
+        printElement(document.createElementNS('http://www.w3.org/1999/xhtml', 'foo'));
+        printElement(document.createElementNS('http://www.w3.org/2000/svg', 'foo'));
+        printElement(document.createElementNS('http://www.w3.org/1998/Math/MathML', 'foo'));
+    });
+</script>
diff --git a/Userland/Libraries/LibWeb/DOM/ElementFactory.cpp b/Userland/Libraries/LibWeb/DOM/ElementFactory.cpp
@@ -430,7 +430,7 @@ static JS::NonnullGCPtr<Element> create_html_element(JS::Realm& realm, Document&
     return realm.heap().allocate<HTML::HTMLUnknownElement>(realm, document, move(qualified_name));
 }
 
-static JS::GCPtr<SVG::SVGElement> create_svg_element(JS::Realm& realm, Document& document, QualifiedName qualified_name)
+static JS::NonnullGCPtr<SVG::SVGElement> create_svg_element(JS::Realm& realm, Document& document, QualifiedName qualified_name)
 {
     auto const& local_name = qualified_name.local_name();
 
@@ -492,17 +492,22 @@ static JS::GCPtr<SVG::SVGElement> create_svg_element(JS::Realm& realm, Document&
     if (local_name == SVG::TagNames::image)
         return realm.heap().allocate<SVG::SVGImageElement>(realm, document, move(qualified_name));
 
-    return nullptr;
+    // https://svgwg.org/svg2-draft/types.html#ElementsInTheSVGDOM
+    // Elements in the SVG namespace whose local name does not match an element defined in any
+    // specification supported by the software must nonetheless implement the SVGElement interface.
+    return realm.heap().allocate<SVG::SVGElement>(realm, document, move(qualified_name));
 }
 
-static JS::GCPtr<MathML::MathMLElement> create_mathml_element(JS::Realm& realm, Document& document, QualifiedName qualified_name)
+static JS::NonnullGCPtr<MathML::MathMLElement> create_mathml_element(JS::Realm& realm, Document& document, QualifiedName qualified_name)
 {
-    auto const& local_name = qualified_name.local_name();
+    // https://w3c.github.io/mathml-core/#dom-and-javascript
+    // All the nodes representing MathML elements in the DOM must implement, and expose to scripts,
+    // the following MathMLElement interface.
 
-    if (local_name.is_one_of(MathML::TagNames::annotation, MathML::TagNames::annotation_xml, MathML::TagNames::maction, MathML::TagNames::math, MathML::TagNames::merror, MathML::TagNames::mfrac, MathML::TagNames::mi, MathML::TagNames::mmultiscripts, MathML::TagNames::mn, MathML::TagNames::mo, MathML::TagNames::mover, MathML::TagNames::mpadded, MathML::TagNames::mphantom, MathML::TagNames::mprescripts, MathML::TagNames::mroot, MathML::TagNames::mrow, MathML::TagNames::ms, MathML::TagNames::mspace, MathML::TagNames::msqrt, MathML::TagNames::mstyle, MathML::TagNames::msub, MathML::TagNames::msubsup, MathML::TagNames::msup, MathML::TagNames::mtable, MathML::TagNames::mtd, MathML::TagNames::mtext, MathML::TagNames::mtr, MathML::TagNames::munder, MathML::TagNames::munderover, MathML::TagNames::semantics))
-        return realm.heap().allocate<MathML::MathMLElement>(realm, document, move(qualified_name));
+    // https://w3c.github.io/mathml-core/#mathml-elements-and-attributes
+    // The term MathML element refers to any element in the MathML namespace.
 
-    return nullptr;
+    return realm.heap().allocate<MathML::MathMLElement>(realm, document, move(qualified_name));
 }
 // https://dom.spec.whatwg.org/#concept-create-element
 WebIDL::ExceptionOr<JS::NonnullGCPtr<Element>> create_element(Document& document, FlyString local_name, Optional<FlyString> namespace_, Optional<FlyString> prefix, Optional<String> is_value, bool synchronous_custom_elements_flag)
@@ -654,20 +659,16 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Element>> create_element(Document& document
 
     if (namespace_ == Namespace::SVG) {
         auto element = create_svg_element(realm, document, qualified_name);
-        if (element) {
-            element->set_is_value(move(is_value));
-            element->set_custom_element_state(CustomElementState::Uncustomized);
-            return JS::NonnullGCPtr<Element> { *element };
-        }
+        element->set_is_value(move(is_value));
+        element->set_custom_element_state(CustomElementState::Uncustomized);
+        return element;
     }
 
     if (namespace_ == Namespace::MathML) {
         auto element = create_mathml_element(realm, document, qualified_name);
-        if (element) {
-            element->set_is_value(move(is_value));
-            element->set_custom_element_state(CustomElementState::Uncustomized);
-            return JS::NonnullGCPtr<Element> { *element };
-        }
+        element->set_is_value(move(is_value));
+        element->set_custom_element_state(CustomElementState::Uncustomized);
+        return element;
     }
 
     // 8. Return result.