Ref: https://dom.spec.whatwg.org/#interface-attr

(*
[Exposed=Window]
interface Attr : Node {
  readonly attribute DOMString? namespaceURI;
  readonly attribute DOMString? prefix;
  readonly attribute DOMString localName;
  readonly attribute DOMString name;
  [CEReactions] attribute DOMString value;
  readonly attribute Element? ownerElement;
  readonly attribute boolean specified; // useless; always returns true
};
*)
TJSDOMString = String;
//  TJSAttr = class external name 'Attr' (TJSObject)
  TJSAttr = class external name 'Attr' (TJSNode)
  private
    fNameSpaceURI: TJSDOMString external name 'namespaceURI';
    fPrefix: TJSDOMString; external name 'prefix';
    fLocalName: TJSDOMString; external name 'localName';
    fName: TJSDOMString; external name 'name';
    fvalue: TJSDOMString; external name 'value';
    fspecified: Boolean; external name 'specified';
  public
    property namespaceURI: TJSDOMString read fNameSpaceURI;
    property prefix: TJSDOMString read fPrefix;
    property localName: TJSDOMString read fLocalName;
    property name: TJSDOMString read fName;
    property value: TJSDOMString read fvalue;
    property specified: Boolean read fspecified;
  end;

This class alread exists in the web unit.
It just misses the specified property, which is useless anyway.

Michael.

the 'Attr' definition inherits from TJSNode not from TJSObject

warleyalex wrote

the 'Attr' definition inherits from TJSNode not from TJSObject

Well spotted ! Fixed, thanks !

Michael.