Fix 500 errors in parser + add caching

infomate/settings.py

@@ -120,6 +120,7 @@ MEDIA_UPLOAD_CODE = None  # should be set in private_settings.py
 TELEGRAM_APP_ID = None  # should set in private_settings.py
 TELEGRAM_APP_HASH = None  # should set in private_settings.py
 TELEGRAM_SESSION_FILE = None  # should set in private settings.py
+TELEGRAM_CACHE_SECONDS = 10 * 60  # 10 min
 
 try:
     # poor mans' private settings

infomate/urls.py

@@ -1,7 +1,9 @@
 from django.urls import path
+from django.views.decorators.cache import cache_page
 
 from auth.views import login, logout, club_callback
 from boards.views import index, board, privacy_policy, what, export
+from infomate import settings
 from parsing.views import TelegramChannelFeed
 
 urlpatterns = [
@@ -16,5 +18,8 @@ urlpatterns = [
 
     path("<slug:board_slug>/", board, name="board"),
     path("<slug:board_slug>/export/", export, name="export"),
-    path("parsing/telegram/<str:channel>/", TelegramChannelFeed(), name="telegram_channel_feed")
+
+    path("parsing/telegram/<str:channel>/",
+         cache_page(settings.TELEGRAM_CACHE_SECONDS)(TelegramChannelFeed()),
+         name="telegram_channel_feed")
 ]

parsing/exceptions.py

@@ -0,0 +1,2 @@
+class ParsingException(Exception):
+    pass

parsing/telegram/telegram.py

@@ -1,5 +1,7 @@
 from telethon.sync import TelegramClient, functions
 from django.conf import settings
+
+from parsing.exceptions import ParsingException
 from parsing.telegram.parsers import Parser, parse_channel
 from parsing.telegram.models import MessageType
 import asyncio
@@ -14,11 +16,16 @@ def get_channel(channel_id, messages_limit):
         settings.TELEGRAM_APP_HASH,
         loop=loop,
     ) as client:
-        channel = parse_channel(
-            channel_id,
-            client(functions.channels.GetFullChannelRequest(channel=channel_id)),
-        )
+        try:
+            channel = parse_channel(
+                channel_id,
+                client(functions.channels.GetFullChannelRequest(channel=channel_id)),
+            )
+        except ValueError:
+            raise ParsingException(f"No channel named '{channel_id}'")
+
         channel.messages = __get_channel_messages(client, channel, messages_limit)
+
     return channel
 
 

parsing/views.py

@@ -1,4 +1,7 @@
 from django.contrib.syndication.views import Feed
+from django.http import Http404
+
+from parsing.exceptions import ParsingException
 from parsing.telegram.telegram import get_channel
 
 
@@ -10,7 +13,11 @@ class TelegramChannelFeed(Feed):
         feed_items = (
             int(request.GET["size"]) if "size" in request.GET else self.FEED_ITEMS
         )
-        return get_channel(channel, feed_items)
+
+        try:
+            return get_channel(channel, feed_items)
+        except ParsingException:
+            raise Http404()
 
     def title(self, obj):
         return obj.title