views: Rename *topic local variables to *topic_name.

This is preparatory work towards adding a Topic model.
We plan to use the local variable name as 'topic' for
the Topic model objects.

Currently, we use *topic as the local variable name for
topic names.

We rename local variables of the form *topic to *topic_name
so that we don't need to think about type collisions in
individual code paths where we might want to talk about both
Topic objects and strings for the topic name.

zerver/lib/home.py

@@ -137,7 +137,7 @@ def build_page_params_for_home_page_load(
     insecure_desktop_app: bool,
     narrow: List[NarrowTerm],
     narrow_stream: Optional[Stream],
-    narrow_topic: Optional[str],
+    narrow_topic_name: Optional[str],
     first_in_realm: bool,
     prompt_for_invites: bool,
     needs_tutorial: bool,
@@ -255,8 +255,8 @@ def build_page_params_for_home_page_load(
         if max_message:
             page_params["max_message_id"] = max_message.id
         page_params["narrow_stream"] = narrow_stream.name
-        if narrow_topic is not None:
-            page_params["narrow_topic"] = narrow_topic
+        if narrow_topic_name is not None:
+            page_params["narrow_topic"] = narrow_topic_name
         page_params["narrow"] = [
             dict(operator=term.operator, operand=term.operand) for term in narrow
         ]

zerver/views/home.py

@@ -110,7 +110,7 @@ def detect_narrowed_window(
 
     narrow: List[NarrowTerm] = []
     narrow_stream = None
-    narrow_topic = request.GET.get("topic")
+    narrow_topic_name = request.GET.get("topic")
 
     if "stream" in request.GET:
         try:
@@ -121,9 +121,9 @@ def detect_narrowed_window(
             narrow = [NarrowTerm(operator="stream", operand=narrow_stream.name)]
         except Exception:
             logging.warning("Invalid narrow requested, ignoring", extra=dict(request=request))
-        if narrow_stream is not None and narrow_topic is not None:
-            narrow.append(NarrowTerm(operator="topic", operand=narrow_topic))
-    return narrow, narrow_stream, narrow_topic
+        if narrow_stream is not None and narrow_topic_name is not None:
+            narrow.append(NarrowTerm(operator="topic", operand=narrow_topic_name))
+    return narrow, narrow_stream, narrow_topic_name
 
 
 def update_last_reminder(user_profile: Optional[UserProfile]) -> None:
@@ -207,7 +207,7 @@ def home_real(request: HttpRequest) -> HttpResponse:
     if need_accept_tos(user_profile):
         return accounts_accept_terms(request)
 
-    narrow, narrow_stream, narrow_topic = detect_narrowed_window(request, user_profile)
+    narrow, narrow_stream, narrow_topic_name = detect_narrowed_window(request, user_profile)
 
     if user_profile is not None:
         first_in_realm = realm_user_count(user_profile.realm) == 1
@@ -232,7 +232,7 @@ def home_real(request: HttpRequest) -> HttpResponse:
         insecure_desktop_app=insecure_desktop_app,
         narrow=narrow,
         narrow_stream=narrow_stream,
-        narrow_topic=narrow_topic,
+        narrow_topic_name=narrow_topic_name,
         first_in_realm=first_in_realm,
         prompt_for_invites=prompt_for_invites,
         needs_tutorial=needs_tutorial,

zerver/views/message_edit.py

@@ -34,7 +34,7 @@ def fill_edit_history_entries(
     """
     prev_content = message.content
     prev_rendered_content = message.rendered_content
-    prev_topic = message.topic_name()
+    prev_topic_name = message.topic_name()
 
     # Make sure that the latest entry in the history corresponds to the
     # message's last edit time
@@ -48,13 +48,13 @@ def fill_edit_history_entries(
             "content": prev_content,
             "rendered_content": prev_rendered_content,
             "timestamp": edit_history_event["timestamp"],
-            "topic": prev_topic,
+            "topic": prev_topic_name,
             "user_id": edit_history_event["user_id"],
         }
 
         if "prev_topic" in edit_history_event:
-            prev_topic = edit_history_event["prev_topic"]
-            formatted_entry["prev_topic"] = prev_topic
+            prev_topic_name = edit_history_event["prev_topic"]
+            formatted_entry["prev_topic"] = prev_topic_name
 
         # Fill current values for content/rendered_content.
         if "prev_content" in edit_history_event:
@@ -79,7 +79,7 @@ def fill_edit_history_entries(
         "content": prev_content,
         "rendered_content": prev_rendered_content,
         "timestamp": datetime_to_timestamp(message.date_sent),
-        "topic": prev_topic,
+        "topic": prev_topic_name,
         "user_id": message.sender_id,
     }