fixes

assets/src/model.js

@@ -42,7 +42,7 @@ export default class Model {
     }
 
     get errors() {
-        return this.data.__errors__
+        return this.data && this.data.__errors__
     }
 
     /**
@@ -143,6 +143,13 @@ export default class Model {
         return item === null ? item : new this(JSON.parse(item));
     }
 
+    /**
+     * Return true if model instance has no data
+     */
+    get isEmpty() {
+        return !this.data || Object.keys(this.data).findIndex(k => !!this.data[k] && this.data[k] !== 0) == -1
+    }
+
     /**
      * Return error for a specific attribute name if any 
      */