From 1e642089cbe8643ce8d85cfe0ec28d6ad5730ee1 Mon Sep 17 00:00:00 2001
From: kangwei <bingbing.yb@alibaba-inc.com>
Date: Mon, 20 Apr 2020 16:01:22 +0800
Subject: [PATCH] polyfill getRoot

---
 packages/designer/src/document/document-model.ts | 5 +++++
 packages/designer/src/document/node/node.ts      | 2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/packages/designer/src/document/document-model.ts b/packages/designer/src/document/document-model.ts
index 8676972d0..13b2e19d3 100644
--- a/packages/designer/src/document/document-model.ts
+++ b/packages/designer/src/document/document-model.ts
@@ -450,6 +450,11 @@ export class DocumentModel {
     const config = parent.componentMeta;
     return config.checkNestingDown(parent, obj) && this.checkNestingUp(parent, obj);
   }
+
+  // ======= compatibles
+  getRoot() {
+    return this.rootNode;
+  }
 }
 
 export function isDocumentModel(obj: any): obj is DocumentModel {
diff --git a/packages/designer/src/document/node/node.ts b/packages/designer/src/document/node/node.ts
index 84f9080be..5679c8d33 100644
--- a/packages/designer/src/document/node/node.ts
+++ b/packages/designer/src/document/node/node.ts
@@ -469,7 +469,7 @@ export class Node {
 
   // ======= compatibles ====
   isEmpty(): boolean {
-    return this.children?.isEmpty() || true;
+    return this.children ? this.children.isEmpty() : true;
   }
   getStatus() {
     return 'default';