JS: Add Element::attributes and NamedNodeMap to handle it

This is a *very* rudimentary implementation lacking most of the
functionality of NamedNodeMap but it's enough to get jQuery 1.12.4 up.

Signed-off-by: Daniel Silverstone <dsilvers@digital-scurf.org>

content/handlers/javascript/duktape/Element.bnd

@@ -514,3 +514,31 @@ out:
 	}
 	return 0;
 %}
+
+getter Element::attributes()
+%{
+	dom_exception exc;
+	dom_namednodemap *nmap = NULL;
+	duk_set_top(ctx, 0);
+	duk_push_this(ctx);
+	duk_get_prop_string(ctx, 0, MAGIC(attributes));
+	if (duk_is_undefined(ctx, -1)) {
+		duk_pop(ctx);
+		exc = dom_node_get_attributes(priv->parent.node, &nmap);
+		if (exc != DOM_NO_ERR) return 0;
+		dukky_push_generics(ctx, "makeNodeMapProxy");
+		duk_push_pointer(ctx, nmap);
+		if (dukky_create_object(ctx, PROTO_NAME(NAMEDNODEMAP), 1) != DUK_EXEC_SUCCESS) {
+			dom_namednodemap_unref(nmap);
+			return 0;
+		}
+		dom_namednodemap_unref(nmap);
+		if (dukky_pcall(ctx, 1, false) != 0) {
+			NSLOG(dukky, DEBUG, "Unable to construct nodelist?");
+			return 0; /* coerced to undefined */
+		}
+		duk_dup(ctx, -1);
+		duk_put_prop_string(ctx, 0, MAGIC(attributes));
+	}
+	return 1;
+%}

content/handlers/javascript/duktape/NamedNodeMap.bnd

@@ -0,0 +1,74 @@
+/* NamedNodeMap binding for browser using duktape and libdom
+ *
+ * Copyright 2020 Daniel Silverstone <dsilvers@netsurf-browser.org>
+ *
+ * This file is part of NetSurf, http://www.netsurf-browser.org/
+ *
+ * Released under the terms of the MIT License,
+ *         http://www.opensource.org/licenses/mit-license
+ */
+
+class NamedNodeMap {
+	private struct dom_namednodemap *map;
+};
+
+init NamedNodeMap(struct dom_namednodemap *map)
+%{
+	priv->map = map;
+	dom_namednodemap_ref(map);
+%}
+
+fini NamedNodeMap()
+%{
+	dom_namednodemap_unref(priv->map);
+%}
+
+getter NamedNodeMap::length()
+%{
+	dom_exception err;
+	uint32_t len;
+
+	err = dom_namednodemap_get_length(priv->map, &len);
+
+	if (err != DOM_NO_ERR) return 0; /* coerced to undefined */
+
+	duk_push_uint(ctx, (duk_uint_t)len);
+
+	return 1;
+%}
+
+method NamedNodeMap::item()
+%{
+	unsigned long i = duk_to_uint(ctx, 0);
+	dom_exception err;
+	dom_node *node;
+
+	err = dom_namednodemap_item(priv->map, i, &node);
+
+	if (err != DOM_NO_ERR) return 0; /* coerced to undefined */
+
+	dukky_push_node(ctx, node);
+	dom_node_unref(node);
+
+	return 1;
+%}
+
+method NamedNodeMap::getNamedItem()
+%{
+	duk_size_t size;
+	const char *s = duk_safe_to_lstring(ctx, 0, &size);
+	dom_exception exc;
+	dom_node *attr = NULL;
+	dom_string *name = NULL;
+
+	exc = dom_string_create((const uint8_t*)s, size, &name);
+	if (exc != DOM_NO_ERR) return 0; /* coerced to undefined */
+	
+	exc = dom_namednodemap_get_named_item(priv->map, name, &attr);
+	dom_string_unref(name);
+	if (exc != DOM_NO_ERR) return 0; /* coerced to undefined */
+	
+	dukky_push_node(ctx, attr);
+	dom_node_unref(attr);
+	return 1;
+%}

content/handlers/javascript/duktape/netsurf.bnd

@@ -60,6 +60,7 @@ struct dom_html_br_element;
 #include "Document.bnd"
 #include "Node.bnd"
 #include "NodeList.bnd"
+#include "NamedNodeMap.bnd"
 #include "Element.bnd"
 #include "HTMLCollection.bnd"
 #include "Location.bnd"