add

src/core/4.widget.js

@@ -29,6 +29,7 @@
                 tagName: "div",
                 attributes: null,
                 data: null,
+                key: null,
 
                 tag: null,
                 disabled: false,
@@ -135,6 +136,9 @@
             if (o._baseCls || o.baseCls || o.extraCls || o.cls) {
                 this.element.addClass((o._baseCls || "") + " " + (o.baseCls || "") + " " + (o.extraCls || "") + " " + (o.cls || ""));
             }
+            if (o.key != null) {
+                this.element.attr("key", o.key);
+            }
             if (o.attributes) {
                 this.element.attr(o.attributes);
             }

src/core/element2Snabbdom.js

@@ -15,12 +15,14 @@
             };
         });
         var style = parentNode.getAttribute("style");
+        var key = parentNode.getAttribute("key");
         // var claz = parentNode.getAttribute("class");
         var vnode = BI.Snabbdom.h(parentNode.nodeName, {
             class: BI.makeObject(parentNode.classList),
             props: {
                 style: style
             },
+            key: key,
             on: on,
             hook: {
                 create: function () {