Updated the script for generating RSS feeds

Author: dalj8690

generate_rss.py

@@ -1,13 +1,13 @@
 import os
 import xml.etree.ElementTree as ET
-from datetime import datetime
+from datetime import datetime, timezone
 from email.utils import parsedate_to_datetime
 
-# Path to your docs folder
+# Path to your docs folder and RSS file
 docs_folder = 'docs'
-rss_file = 'docs/rss.xml'
+rss_file = os.path.join(docs_folder, 'rss.xml')
 
-# Get a list of all PDF files in docs and its subdirectories
+# Collect all PDF files in docs/
 pdf_files = []
 for root, dirs, files in os.walk(docs_folder):
     for file in files:
@@ -16,7 +16,7 @@
 
 print(f"Found {len(pdf_files)} PDFs in the 'docs' folder.")
 
-# Create or load RSS XML
+# Load existing RSS or create a new one
 if os.path.exists(rss_file):
     tree = ET.parse(rss_file)
     root = tree.getroot()
@@ -28,49 +28,65 @@
     ET.SubElement(channel, "link").text = "https://github.com/damirlj/modern_cpp_tutorials"
     ET.SubElement(channel, "description").text = "New articles and updates in the docs/ folder"
 
-# Map from GUID to <item> for quick lookup
-existing_items = {}
-for item in channel.findall("item"):
-    guid = item.find("guid").text if item.find("guid") is not None else None
-    if guid:
-        existing_items[guid] = item
+# Map existing GUIDs to pubDate
+existing_items = {
+    item.find("guid").text: item.find("pubDate").text
+    for item in channel.findall("item") if item.find("guid") is not None
+}
 
-# Track updated list of items
+# Prepare new items
 new_items = []
+current_date = datetime.now(timezone.utc).strftime("%a, %d %b %Y %H:%M:%S GMT")
+changes_made = False
 
-# Generate items from current PDF list
-for pdf in pdf_files:
+for pdf in sorted(pdf_files):
     relative_path = os.path.relpath(pdf, docs_folder)
-    commit_url = f"https://github.com/damirlj/modern_cpp_tutorials/blob/main/{relative_path}"
-
-    # If this article already exists, preserve pubDate
-    if commit_url in existing_items:
-        old_item = existing_items[commit_url]
-        pub_date = old_item.find("pubDate").text
-        pub_datetime = parsedate_to_datetime(pub_date)
-    else:
-        # New item - use current time
-        pub_datetime = datetime.utcnow()
+    link = f"https://github.com/damirlj/modern_cpp_tutorials/blob/main/{relative_path}"
 
+    # Check if the item already exists
     item = ET.Element("item")
     ET.SubElement(item, "title").text = relative_path
-    ET.SubElement(item, "link").text = commit_url
-    ET.SubElement(item, "guid").text = commit_url
-    ET.SubElement(item, "pubDate").text = pub_datetime.strftime("%a, %d %b %Y %H:%M:%S GMT")
+    ET.SubElement(item, "link").text = link
+    ET.SubElement(item, "guid").text = link
 
-    new_items.append((pub_datetime, item))
+    # Preserve existing pubDate or assign new one
+    if link in existing_items:
+        pub_date = existing_items[link]  # Preserve timestamp of existing item
+        # Remove the old version if it's updated (duplicate)
+        for old_item in channel.findall("item"):
+            if old_item.find("guid").text == link:
+                channel.remove(old_item)
+                changes_made = True
+                break
+    else:
+        pub_date = current_date  # New items get the current date
 
-# Sort items newest-first by pubDate
-new_items.sort(key=lambda x: x[0], reverse=True)
+    ET.SubElement(item, "pubDate").text = current_date if link not in existing_items else pub_date
+
+    # If the item is new, add it to the list of new items
+    if link not in existing_items:
+        new_items.append((parsedate_to_datetime(pub_date), item))
+        changes_made = True
+    else:
+        # For updated items, we already removed the old item and added the new one
+        new_items.append((parsedate_to_datetime(pub_date), item))
 
-# Clear old items and re-append in sorted order
+# If no changes were made (no new items and no updates), exit early
+if not changes_made:
+    print("No new or updated items found. Exiting without writing.")
+    exit(0)
+
+# Sort with newest items at the top
+new_items.sort(key=lambda tup: tup[0], reverse=True)
+
+# Clear old items and append new ones (sorted)
 for old_item in channel.findall("item"):
     channel.remove(old_item)
+
 for _, item in new_items:
     channel.append(item)
 
 # Save the updated RSS feed
 tree = ET.ElementTree(root)
 tree.write(rss_file, encoding="UTF-8", xml_declaration=True)
-
 print(f"Generated RSS feed with {len(new_items)} articles.")