Added support to allow only public slack channels

llama-index-integrations/readers/llama-index-readers-slack/llama_index/readers/slack/base.py

@@ -243,14 +243,12 @@ def _is_regex(self, pattern: str) -> bool:
         except re.error:
             return False
 
-    def _list_channels(self) -> List[Dict[str, Any]]:
-        """List all channels (public and private)."""
+    def _list_channels(self, types: str) -> List[Dict[str, Any]]:
+        """List channels based on the types."""
         from slack_sdk.errors import SlackApiError
 
         try:
-            result = self._client.conversations_list(
-                types="public_channel,private_channel"
-            )
+            result = self._client.conversations_list(types=types)
             return result["channels"]
         except SlackApiError as e:
             logger.error(f"Error fetching channels: {e.response['error']}")
@@ -275,7 +273,9 @@ def _filter_channels(
                     filtered_channels.append(channel)
         return filtered_channels
 
-    def get_channel_ids(self, channel_patterns: List[str]) -> List[str]:
+    def get_channel_ids(
+        self, channel_patterns: List[str], types: str = "public_channel,private_channel"
+    ) -> List[str]:
         """Get list of channel IDs based on names and regex patterns.
 
         Args:
@@ -287,7 +287,7 @@ def get_channel_ids(self, channel_patterns: List[str]) -> List[str]:
         if not channel_patterns:
             raise ValueError("No channel patterns provided.")
 
-        channels = self._list_channels()
+        channels = self._list_channels(types)
         logger.info(f"Total channels fetched: {len(channels)}")
 
         if not channels: