addExternalElementToElement method

Implementation

@override
List<Node>? addExternalElementToElement(
    Node element, Object? externalElement) {
  if (externalElement == null) return null;
  if (!element.isA<Element>()) return null;

  externalElement = resolveElements(externalElement);

  if (externalElement is List) {
    var added = <Node>[];
    for (var e in externalElement) {
      if (e == null) continue;

      if (e is List) {
        var l = addExternalElementToElement(element, e);
        if (l != null) {
          added.addAll(l);
        }
      } else {
        var jsAny = externalElement.asJSAny;
        if (jsAny.isA<Node>()) {
          var node = jsAny as Node;
          element.appendChild(node);
          added.add(node);
        }
      }
    }
    return added;
  } else {
    var jsAny = externalElement.asJSAny;
    if (jsAny.isA<Node>()) {
      var node = jsAny as Node;
      element.appendChild(node);
      return [node];
    }
  }

  return null;
}