1 files changed, 6 insertions, 1 deletions
diff --git a/script.js b/script.js
index 0e117d06..3345e32b 100644
--- a/script.js
+++ b/script.js
@@ -1,5 +1,6 @@
 function gradioApp() {
-    const gradioShadowRoot = document.getElementsByTagName('gradio-app')[0].shadowRoot
+    const elems = document.getElementsByTagName('gradio-app')
+    const gradioShadowRoot = elems.length == 0 ? null : elems[0].shadowRoot
     return !!gradioShadowRoot ? gradioShadowRoot : document;
 }
 
@@ -13,6 +14,7 @@ function get_uiCurrentTabContent() {
 
 uiUpdateCallbacks = []
 uiTabChangeCallbacks = []
+optionsChangedCallbacks = []
 let uiCurrentTab = null
 
 function onUiUpdate(callback){
@@ -21,6 +23,9 @@ function onUiUpdate(callback){
 function onUiTabChange(callback){
     uiTabChangeCallbacks.push(callback)
 }
+function onOptionsChanged(callback){
+    optionsChangedCallbacks.push(callback)
+}
 
 function runCallback(x, m){
     try {