Merge branch 'prop/preserve-state'

1 files changed, 13 insertions, 18 deletions

diff --git a/ui/routes/(app)/ch/[channel]/+page.svelte b/ui/routes/(app)/ch/[channel]/+page.svelte
index 8de9859..095e66a 100644
--- a/ui/routes/(app)/ch/[channel]/+page.svelte
+++ b/ui/routes/(app)/ch/[channel]/+page.svelte
@@ -3,7 +3,7 @@
   import { page } from '$app/state';
   import ActiveChannel from '$lib/components/ActiveChannel.svelte';
   import MessageInput from '$lib/components/MessageInput.svelte';
-  import { channelsList, currentUser, logins, messages } from '$lib/store';
+  import { channelsList, channelsMetaList, currentUser, logins, messages } from '$lib/store';
   import * as api from '$lib/apiServer';
 
   let channel = $derived(page.params.channel);
@@ -34,27 +34,22 @@
   }
 
   function getLastVisibleMessage() {
-    const parentElement = activeChannel;
-    const childElements = parentElement.getElementsByClassName('message');
-    const lastInView = Array.from(childElements)
-      .reverse()
-      .find((el) => {
-        return inView(parentElement, el);
-      });
-    return lastInView;
+    if (activeChannel) {
+      const childElements = activeChannel.getElementsByClassName('message');
+      const lastInView = Array.from(childElements)
+        .reverse()
+        .find((el) => {
+          return inView(activeChannel, el);
+        });
+      return lastInView;
+    }
   }
 
   function setLastRead() {
-    const channelObject = $channelsList.getChannel(channel);
     const lastInView = getLastVisibleMessage();
-    if (!channelObject || !lastInView) {
-      return;
-    }
-    const at = DateTime.fromISO(lastInView.dataset.at);
-    // Do it this way, rather than with Math.max tricks, to avoid assignment
-    // when we don't need it, to minimize reactive changes:
-    if (at > channelObject.lastReadAt) {
-      channelObject.lastReadAt = at;
+    if (lastInView) {
+      const at = DateTime.fromISO(lastInView.dataset.at);
+      $channelsMetaList.updateLastReadAt(channel, at);
     }
   }