From c6fe331fe948a9dc1102b344c9ee1a7451027934 Mon Sep 17 00:00:00 2001
From: Jim O'Donnell <jim@zooniverse.org>
Date: Tue, 29 Mar 2022 23:13:08 +0100
Subject: [PATCH] Add a popstate handler Add history state for back/forward
 navigation.

---
 packages/lib-classifier/dev/components/App/App.js | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/packages/lib-classifier/dev/components/App/App.js b/packages/lib-classifier/dev/components/App/App.js
index 01598f96a4..1e82127fd7 100644
--- a/packages/lib-classifier/dev/components/App/App.js
+++ b/packages/lib-classifier/dev/components/App/App.js
@@ -25,12 +25,20 @@ class App extends React.Component {
   }
 
   componentDidMount () {
+    addEventListener('popstate', this.onPopState.bind(this))
     this.initAuthorization()
       .then(() => {
         this.fetchProject()
       })
   }
 
+  onPopState({ state }) {
+    const url = new URL(window.location)
+    const { searchParams } = url
+    const workflowID = searchParams.get('workflow')
+    this.setState({ workflowID })
+  }
+
   onError (error, info) {
     console.error(error)
   }
@@ -125,7 +133,7 @@ class App extends React.Component {
     } else {
       newParams.set('workflow', workflowID)
     }
-    history.pushState(null, '', `/?${newParams.toString()}`)
+    history.pushState({ workflowID }, '', `/?${newParams.toString()}`)
   }
 
   toggleTheme () {