From 71622e2932bc05ba53209f9d765752d547c78520 Mon Sep 17 00:00:00 2001
From: tusooa <tusooa@kazv.moe>
Date: Thu, 22 Aug 2024 21:06:19 -0400
Subject: [PATCH] Save draft on window's beforeunload event

---
 .../post_status_form/post_status_form.js      | 21 +++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/src/components/post_status_form/post_status_form.js b/src/components/post_status_form/post_status_form.js
index 63452747..1ae98549 100644
--- a/src/components/post_status_form/post_status_form.js
+++ b/src/components/post_status_form/post_status_form.js
@@ -354,10 +354,20 @@ const PostStatusForm = {
       handler () {
         this.statusChanged()
       }
+    },
+    savable (val) {
+      // https://developer.mozilla.org/en-US/docs/Web/API/Window/beforeunload_event#usage_notes
+      // MDN says we'd better add the beforeunload event listener only when needed, and remove it when it's no longer needed
+      if (val) {
+        this.addBeforeUnloadListener()
+      } else {
+        this.removeBeforeUnloadListener()
+      }
     }
   },
   beforeUnmount () {
     this.maybeAutoSaveDraft()
+    this.removeBeforeUnloadListener()
   },
   methods: {
     statusChanged () {
@@ -785,6 +795,17 @@ const PostStatusForm = {
       this.abandonDraft().then(() => {
         this.$emit('can-close')
       })
+    },
+    addBeforeUnloadListener () {
+      this._beforeUnloadListener ||= () => {
+        this.saveDraft()
+      }
+      window.addEventListener('beforeunload', this._beforeUnloadListener)
+    },
+    removeBeforeUnloadListener () {
+      if (this._beforeUnloadListener) {
+        window.removeEventListener('beforeunload', this._beforeUnloadListener)
+      }
     }
   }
 }