From 2fd022949389cadcaf50919e2cc8fc463fcdaa6c Mon Sep 17 00:00:00 2001
From: Ningxin Hu <ningxin.hu@intel.com>
Date: Wed, 27 Sep 2017 16:43:25 +0800
Subject: [PATCH] Check files uploaded by user

---
 doc/js_tutorials/js_assets/utils.js | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/doc/js_tutorials/js_assets/utils.js b/doc/js_tutorials/js_assets/utils.js
index e7b21a3e35..8e56396aba 100644
--- a/doc/js_tutorials/js_assets/utils.js
+++ b/doc/js_tutorials/js_assets/utils.js
@@ -98,8 +98,11 @@ function Utils(errorOutputId) { // eslint-disable-line no-unused-vars
     this.addFileInputHandler = function(fileInputId, canvasId) {
         let inputElement = document.getElementById(fileInputId);
         inputElement.addEventListener('change', (e) => {
-            let imgUrl = URL.createObjectURL(e.target.files[0]);
-            self.loadImageToCanvas(imgUrl, canvasId);
+            let files = e.target.files;
+            if (files.length > 0) {
+                let imgUrl = URL.createObjectURL(files[0]);
+                self.loadImageToCanvas(imgUrl, canvasId);
+            }
         }, false);
     };