drafts: Add placeholder text for drafts with no channel selected.

This commit handles the empty channel placeholder for drafts saved
without a channel selected. When these drafts also do not have a topic,
we display "No topic selected" in tandem with "No channel selected",
since we are unable to access the channel configuration to determine
if we should display realm_empty_topic_display_name.

web/src/drafts.ts

@@ -646,13 +646,20 @@ export function format_draft(draft: LocalStorageDraftWithId): FormattedDraft | u
         let draft_topic_display_name = draft.topic;
         let is_empty_string_topic = false;
 
-        // If the channel is not known (recipient was not specified while the creation of the
+        if (draft.topic === "") {
-        // draft) and the topic is empty, the draft_topic_display_name will always be empty string
-        // and the draft title will appear as "# >". We don't use the term "general chat" until
-        // the channel is known.
-        if (sub && draft.topic === "" && stream_data.can_use_empty_topic(draft.stream_id)) {
-            draft_topic_display_name = util.get_final_topic_display_name("");
             is_empty_string_topic = true;
+            if (sub && stream_data.can_use_empty_topic(draft.stream_id)) {
+                // If the channel is known and it allows empty topic, we display
+                // the realm_empty_topic_display_name.
+                draft_topic_display_name = util.get_final_topic_display_name("");
+            } else {
+                // If the channel is not known (channel field was empty during the
+                // creation of the draft) or it doesn't allow empty topics, we display
+                // "No topic entered". We can't use realm_empty_topic_display_name
+                // for empty topics in unknown channels, since we are unaware of the
+                // channel's configuration.
+                draft_topic_display_name = $t({defaultMessage: "No topic entered"});
+            }
         }
 
         return {

web/styles/zulip.css

@@ -2460,7 +2460,8 @@ body:not(.spectator-view) {
 
 .default-language-display,
 .empty-topic-display,
-.empty-topic-placeholder-display::placeholder {
+.empty-topic-placeholder-display::placeholder,
+.drafts-unknown-msg-header-field {
     font-style: italic;
 }
 

web/templates/draft.hbs

@@ -10,7 +10,7 @@
                     {{#if stream_name}}
                         {{stream_name}}
                     {{else}}
-                         
+                        <span class="drafts-unknown-msg-header-field">{{t "No channel selected" }}</span>
                     {{/if}}
                 </div>
                 <span class="stream_topic_separator"><i class="zulip-icon zulip-icon-chevron-right"></i></span>

web/tests/drafts.test.cjs

@@ -633,8 +633,8 @@ test("format_drafts", ({override, override_rewire, mock_template}) => {
     assert.deepEqual(draft_model.get(), data);
 
     override(realm, "realm_topics_policy", "disable_empty_topic");
-    expected[5].topic_display_name = "";
+    expected[5].topic_display_name = "translated: No topic entered";
-    expected[5].is_empty_string_topic = false;
+    expected[5].is_empty_string_topic = true;
     assert.deepEqual(draft_model.get(), data);
 
     const stub_render_now = timerender.render_now;