From abd04cb8700e2195ff02c4ffa75adb3523e9d978 Mon Sep 17 00:00:00 2001
From: Faustino Kialungila <Faustino.kialungila@gmail.com>
Date: Mon, 3 Feb 2020 01:27:03 +0100
Subject: [PATCH] Load only valid excalidraw json when drag&drop (#678)

* Load only valid excalidraw json when drag&drop

* fix lint error
---
 src/scene/data.ts | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/scene/data.ts b/src/scene/data.ts
index 584a127e..095c4f65 100644
--- a/src/scene/data.ts
+++ b/src/scene/data.ts
@@ -24,6 +24,9 @@ const BACKEND_GET = "https://json.excalidraw.com/api/v1/";
 (window as any).handle = null;
 
 interface DataState {
+  type?: string;
+  version?: string;
+  source?: string;
   elements: readonly ExcalidrawElement[];
   appState: AppState | null;
   selectedId?: number;
@@ -92,6 +95,9 @@ export async function loadFromBlob(blob: any) {
     let appState = defaultAppState;
     try {
       const data = JSON.parse(contents);
+      if (data.type !== "excalidraw") {
+        throw new Error("Cannot load invalid json");
+      }
       elements = data.elements || [];
       appState = { ...defaultAppState, ...data.appState };
     } catch (e) {
@@ -120,6 +126,9 @@ export async function loadFromBlob(blob: any) {
     })();
   }
   const { elements, appState } = updateAppState(contents);
+  if (!elements.length) {
+    return Promise.reject("Cannot load invalid json");
+  }
   return new Promise<DataState>(resolve => {
     resolve(restore(elements, appState, { scrollToContent: true }));
   });