Add a checkbox that propagates topic edits to subsequent messages.

Trac #1348

(imported from commit 28e2a8cb3ecda5ec50d17501f4ccbd8644212065)

static/js/message_edit.js

@@ -14,6 +14,10 @@ exports.save = function (row) {
         var new_topic = row.find(".message_edit_topic").val();
         if (new_topic !== message.subject && new_topic.trim() !== "") {
             request.subject = new_topic;
+
+            if (row.find(".message_edit_topic_propagate>input").is(":checked")) {
+                request.propagate_subject = true;
+            }
             changed = true;
         }
     }

static/js/zulip.js

@@ -734,23 +734,33 @@ function update_messages(events) {
         }
 
         if (event.subject !== undefined) {
-            // Remove the recent subjects entry for the old subject;
-            // must be called before we update msg.subject
-            process_message_for_recent_subjects(msg, true);
-            // Update the unread counts; again, this must be called
-            // before we update msg.subject
-            unread.update_unread_subjects(msg, event);
+            // A topic edit may affect multiple messages, listed in
+            // event.message_ids. event.message_id is still the first message
+            // where the user initiated the edit.
+            _.each(event.message_ids, function (id) {
+                var msg = all_msg_list.get(id);
+                if (msg === undefined) {
+                    return;
+                }
 
-            msg.subject = event.subject;
-            msg.subject_links = event.subject_links;
-            if (msg.subject === compose.empty_subject_placeholder()) {
-                msg.empty_subject = true;
-            } else {
-                msg.empty_subject = false;
-            }
-            // Add the recent subjects entry for the new subject; must
-            // be called after we update msg.subject
-            process_message_for_recent_subjects(msg);
+                // Remove the recent subjects entry for the old subject;
+                // must be called before we update msg.subject
+                process_message_for_recent_subjects(msg, true);
+                // Update the unread counts; again, this must be called
+                // before we update msg.subject
+                unread.update_unread_subjects(msg, event);
+
+                msg.subject = event.subject;
+                msg.subject_links = event.subject_links;
+                if (msg.subject === compose.empty_subject_placeholder()) {
+                    msg.empty_subject = true;
+                } else {
+                    msg.empty_subject = false;
+                }
+                // Add the recent subjects entry for the new subject; must
+                // be called after we update msg.subject
+                process_message_for_recent_subjects(msg);
+            });
         }
 
         var row = current_msg_list.get_row(event.message_id);

static/styles/zulip.css

@@ -1134,6 +1134,9 @@ table.focused_table {
 .message_edit_content {
     line-height: 18px;
 }
+.message_edit_topic_propagate{
+    display: inline-block;
+}
 
 .message_content.condensed {
     max-height: 8.5em;

static/templates/message_edit_form.handlebars

@@ -6,6 +6,9 @@
         <label class="control-label edit-control-label" for="message_edit_topic">Topic</label>
         <div class="controls edit-controls">
           <input type="text" value="{{topic}}" class="message_edit_topic" id="message_edit_topic">
+          <label class='message_edit_topic_propagate'>
+            <input type="checkbox"> Change all later messages on this topic
+          </label>
         </div>
     </div>
 {{/if}}

zerver/lib/actions.py

@@ -1026,7 +1026,7 @@ def do_update_onboarding_steps(user_profile, steps):
                   users=[user_profile.id])
     tornado_callbacks.send_notification(notice)
 
-def do_update_message(user_profile, message_id, subject, content):
+def do_update_message(user_profile, message_id, subject, propagate_subject, content):
     try:
         message = Message.objects.select_related().get(id=message_id)
     except Message.DoesNotExist:
@@ -1036,6 +1036,7 @@ def do_update_message(user_profile, message_id, subject, content):
              'sender': user_profile.email,
              'message_id': message_id}
     edit_history_event = {}
+    changed_messages = [message]
 
     if message.sender != user_profile:
         if not (message.subject == "(no topic)" and content is None):
@@ -1078,17 +1079,36 @@ def do_update_message(user_profile, message_id, subject, content):
         event["rendered_content"] = rendered_content
 
     if subject is not None:
+        orig_subject = message.subject
         subject = subject.strip()
         if subject == "":
             raise JsonableError("Topic can't be empty")
 
         if len(subject) > MAX_SUBJECT_LENGTH:
             raise JsonableError("Topic too long")
-        event["orig_subject"] = message.subject
+        event["orig_subject"] = orig_subject
         message.subject = subject
         event["subject"] = subject
         event['subject_links'] = bugdown.subject_links(message.sender.realm.domain.lower(), subject)
-        edit_history_event["prev_subject"] = event['orig_subject']
+        edit_history_event["prev_subject"] = orig_subject
+
+        if propagate_subject:
+            messages = Message.objects.filter(
+                recipient = message.recipient,
+                subject = orig_subject,
+                id__gt = message.id
+            ).select_related()
+
+            # Evaluate the query before running the update
+            messages_list = list(messages)
+            messages.update(subject=subject)
+
+            for m in messages_list:
+                # The cached ORM object is not changed by messages.update()
+                # and the memcached update requires the new value
+                m.subject = subject
+
+            changed_messages += messages_list
 
     message.last_edit_time = timezone.now()
     event['edit_timestamp'] = datetime_to_timestamp(message.last_edit_time)
@@ -1107,12 +1127,15 @@ def do_update_message(user_profile, message_id, subject, content):
     # Update the message as stored in both the (deprecated) message
     # cache (for shunting the message over to Tornado in the old
     # get_messages API) and also the to_dict caches.
-    cache_save_message(message)
     items_for_memcached = {}
-    items_for_memcached[to_dict_cache_key(message, True)] = \
-        (stringify_message_dict(message.to_dict_uncached(apply_markdown=True)),)
-    items_for_memcached[to_dict_cache_key(message, False)] = \
-        (stringify_message_dict(message.to_dict_uncached(apply_markdown=False)),)
+    event['message_ids'] = []
+    for changed_message in changed_messages:
+        event['message_ids'].append(changed_message.id)
+        cache_save_message(changed_message)
+        items_for_memcached[to_dict_cache_key(changed_message, True)] = \
+            (stringify_message_dict(changed_message.to_dict_uncached(apply_markdown=True)),)
+        items_for_memcached[to_dict_cache_key(changed_message, False)] = \
+            (stringify_message_dict(changed_message.to_dict_uncached(apply_markdown=False)),)
     cache_set_many(items_for_memcached)
 
     recipients = [um.user_profile_id for um in UserMessage.objects.filter(message=message_id)]

zerver/views/__init__.py

@@ -1267,10 +1267,11 @@ def json_fetch_raw_message(request, user_profile,
 def update_message_backend(request, user_profile,
                            message_id=REQ(converter=to_non_negative_int),
                            subject=REQ(default=None),
+                           propagate_subject=REQ(default=False),
                            content=REQ(default=None)):
     if subject is None and content is None:
         return json_error("Nothing to change")
-    do_update_message(user_profile, message_id, subject, content)
+    do_update_message(user_profile, message_id, subject, propagate_subject, content)
     return json_success()
 
 # We do not @require_login for send_message_backend, since it is used