personal-site/swap_guids.py

78 lines
3.6 KiB
Python

import logging
import pprint
import uuid
from pelican import signals
log = logging.getLogger(__name__)
def modify_feed(context, feed):
articles = {}
for article in context['articles']:
if article.title in articles:
raise Exception(f"Duplicate article title found: {article.title}")
articles[article.title] = article
for item in feed.items:
item_title = item['title']
article = articles.get(item_title)
if not article:
raise Exception(f"Article not found for title: {item_title}")
if not hasattr(article, 'guid') or not article.guid:
log.info(f"Article '{article.title}' ({article.source_path}) is missing a guid. Generating and embedding one.")
new_guid_str = uuid.uuid4().hex
guid_text_to_embed = f"Guid: {new_guid_str}"
source_path = article.source_path
# Ensure article object has the _content attribute
if not hasattr(article, '_content'):
log.error(f"Article '{article.title}' does not have '_content' attribute. Cannot embed Guid into source file.")
raise Exception(f"Cannot find raw content for article '{article.title}' to embed Guid.")
# Read the original file content.
# Python's open() in text mode uses universal newlines by default, converting \r\n and \r to \n.
# Pelican's MarkdownReader also provides article._content with \n newlines.
try:
with open(source_path, 'r', encoding='utf-8') as f:
current_body_content = f.read()
except Exception as e:
log.error(f"Failed to read original content from '{source_path}': {e}")
raise
# Split this body content to find its first paragraph.
# Paragraphs in Markdown are separated by one or more blank lines (\n\n).
body_parts = current_body_content.split('\n\n', 1)
first_paragraph_of_body = body_parts[0]
rest_of_body_content = body_parts[1] if len(body_parts) > 1 else ""
# Append the Guid text to the end of the first paragraph of the body.
# .rstrip() removes any trailing whitespace/newlines from the paragraph itself before appending.
modified_first_paragraph_of_body = first_paragraph_of_body.rstrip() + '\n' + guid_text_to_embed
# Construct the full new file content by combining the original metadata part and the new body.
# This preserves the original metadata block verbatim (including comments, formatting, and original newline characters if any within it,
# as metadata_part_from_file is a direct slice from original_file_content_universal_newlines which has \n newlines).
full_new_content = modified_first_paragraph_of_body + '\n\n' + rest_of_body_content
try:
with open(source_path, 'w', encoding='utf-8') as f:
f.write(full_new_content)
log.info(f"Successfully wrote updated content with embedded Guid to '{source_path}'.")
except Exception as e:
log.error(f"Failed to write updated content to '{source_path}': {e}")
raise # Re-raise the exception to halt processing if file write fails
# Set article.guid for the current Pelican run, so it's used for the feed item
article.guid = new_guid_str
log.debug(f"Set in-memory article.guid = '{new_guid_str}' for '{article.title}'.")
item['unique_id'] = article.guid
def register():
signals.feed_generated.connect(modify_feed)