From a9f7ab785cae4604914b67df70ed2be5e7a3afb7 Mon Sep 17 00:00:00 2001
From: Germain Souquet <germains@element.io>
Date: Thu, 23 Sep 2021 10:59:33 +0100
Subject: [PATCH] Change CIDER state persistence key to cater for threads

Extending the CIDER state persistence to threads and make sure that SendMessageComposer can restore drafts for specific threads

This also prevents the thread's replyToEvent to leaking in the room composer
---
 .../views/rooms/SendMessageComposer.tsx       | 25 ++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/src/components/views/rooms/SendMessageComposer.tsx b/src/components/views/rooms/SendMessageComposer.tsx
index 05c41f74bf..4138b00bdf 100644
--- a/src/components/views/rooms/SendMessageComposer.tsx
+++ b/src/components/views/rooms/SendMessageComposer.tsx
@@ -164,6 +164,20 @@ export default class SendMessageComposer extends React.Component<IProps> {
         window.addEventListener("beforeunload", this.saveStoredEditorState);
     }
 
+    public componentDidUpdate(prevProps: IProps): void {
+        const replyToEventChanged = this.props.replyToEvent !== prevProps.replyToEvent;
+        if (replyToEventChanged) {
+            this.model.reset([]);
+        }
+
+        if (this.props.replyInThread && this.props.replyToEvent && (!prevProps.replyToEvent || replyToEventChanged)) {
+            const partCreator = new CommandPartCreator(this.props.room, this.context);
+            const parts = this.restoreStoredEditorState(partCreator) || [];
+            this.model.reset(parts);
+            this.editorRef.current?.focus();
+        }
+    }
+
     private onKeyDown = (event: KeyboardEvent): void => {
         // ignore any keypress while doing IME compositions
         if (this.editorRef.current?.isComposing(event)) {
@@ -484,7 +498,12 @@ export default class SendMessageComposer extends React.Component<IProps> {
     }
 
     private get editorStateKey() {
-        return `mx_cider_state_${this.props.room.roomId}`;
+        let key = `mx_cider_state_${this.props.room.roomId}`;
+        const thread = this.props.replyToEvent?.getThread();
+        if (thread) {
+            key += `_${thread.id}`;
+        }
+        return key;
     }
 
     private clearStoredEditorState(): void {
@@ -492,6 +511,10 @@ export default class SendMessageComposer extends React.Component<IProps> {
     }
 
     private restoreStoredEditorState(partCreator: PartCreator): Part[] {
+        if (this.props.replyInThread && !this.props.replyToEvent) {
+            return null;
+        }
+
         const json = localStorage.getItem(this.editorStateKey);
         if (json) {
             try {