stream/docs: Add date_created to Stream.API_FIELDS.

The parameter Stream.date_created is now sent down to the clients
for both:

    - client.get_streams()
    - client.list_subscriptions()

API docs updated for stream and subscriptions.

Fixes #15410

zerver/lib/actions.py

@@ -4879,8 +4879,6 @@ def gather_subscriptions_helper(user_profile: UserProfile,
     all_streams = get_active_streams(user_profile.realm).select_related(
         "realm").values(
             *Stream.API_FIELDS,
-            # date_created is used as an input for the stream_weekly_traffic computed field.
-            "date_created",
             # The realm_id and recipient_id are generally not needed in the API.
             "realm_id",
             "recipient_id",
@@ -4934,6 +4932,9 @@ def gather_subscriptions_helper(user_profile: UserProfile,
             if field_name == "id":
                 stream_dict['stream_id'] = stream["id"]
                 continue
+            elif field_name == "date_created":
+                stream_dict['date_created'] = datetime_to_timestamp(stream[field_name])
+                continue
             stream_dict[field_name] = stream[field_name]
 
         # Copy Subscription.API_FIELDS except for "active", which is
@@ -4991,6 +4992,9 @@ def gather_subscriptions_helper(user_profile: UserProfile,
                 if field_name == "id":
                     stream_dict['stream_id'] = stream["id"]
                     continue
+                elif field_name == "date_created":
+                    stream_dict['date_created'] = datetime_to_timestamp(stream[field_name])
+                    continue
                 stream_dict[field_name] = stream[field_name]
 
             stream_dict['stream_weekly_traffic'] = get_average_weekly_stream_traffic(

zerver/lib/event_schema.py

@@ -38,6 +38,7 @@ basic_stream_fields = [
     ("rendered_description", check_string),
     ("stream_id", check_int),
     ("stream_post_policy", check_int),
+    ("date_created", check_int),
 ]
 
 subscription_fields: Sequence[Tuple[str, Validator[object]]] = [

zerver/models.py

@@ -1554,8 +1554,6 @@ class Stream(models.Model):
     # * is_in_zephyr_realm is a backend-only optimization.
     # * "deactivated" streams are filtered from the API entirely.
     # * "realm" and "recipient" are not exposed to clients via the API.
-    # * "date_created" should probably be added here, as it's useful information
-    #   to subscribers.
     API_FIELDS = [
         "name",
         "id",
@@ -1566,7 +1564,8 @@ class Stream(models.Model):
         "stream_post_policy",
         "history_public_to_subscribers",
         "first_message_id",
-        "message_retention_days"
+        "message_retention_days",
+        "date_created",
     ]
 
     @staticmethod
@@ -1580,6 +1579,9 @@ class Stream(models.Model):
             if field_name == "id":
                 result['stream_id'] = self.id
                 continue
+            elif field_name == "date_created":
+                result['date_created'] = datetime_to_timestamp(self.date_created)
+                continue
             result[field_name] = getattr(self, field_name)
         result['is_announcement_only'] = self.stream_post_policy == Stream.STREAM_POST_POLICY_ADMINS
         return result

zerver/openapi/zulip.yaml

@@ -4122,6 +4122,10 @@ components:
             The short description of the stream in text/markdown format,
             intended to be used to prepopulate UI for editing a stream's
             description.
+        date_created:
+          type: integer
+          description: |
+            The UNIX timestamp for when the stream was created, in UTC seconds.
         invite_only:
           type: boolean
           description: |
@@ -4223,6 +4227,10 @@ components:
             work correctly.  And any client-side security logic for
             user-generated message content should be applied when displaying
             this HTML as though it were the body of a Zulip message.
+        date_created:
+          type: integer
+          description: |
+            The UNIX timestamp for when the stream was created, in UTC seconds.
         invite_only:
           type: boolean
           description: |