Merge pull request #3182 from congweibai/dev Fixes #3181

fix SelectorManager not reutrn state string

src/editor/model/Editor.js

@@ -490,7 +490,7 @@ export default Backbone.Model.extend({
    * @returns {String}
    */
   getState() {
-    return this.get('state');
+    return this.get('state') || '';
   },
 
   /**

src/selector_manager/index.js

@@ -163,7 +163,7 @@ export default config => {
      * @returns {String}
      */
     getState() {
-      return this.em.setState();
+      return this.em.getState();
     },
 
     addSelector(name, opt = {}) {