""" Utility functions for RSS feed generation. """ from changedetectionio.jinja2_custom import render as jinja_render from changedetectionio.notification.handler import apply_service_tweaks from loguru import logger import re BAD_CHARS_REGEX = r'[\x00-\x08\x0B\x0C\x0E-\x1F]' def scan_invalid_chars_in_rss(content): """ Scan for invalid characters in RSS content. Returns True if invalid characters are found. """ for match in re.finditer(BAD_CHARS_REGEX, content): i = match.start() bad_char = content[i] hex_value = f"0x{ord(bad_char):02x}" # Grab context start = max(0, i - 20) end = min(len(content), i + 21) context = content[start:end].replace('\n', '\\n').replace('\r', '\\r') logger.warning(f"Invalid char {hex_value} at pos {i}: ...{context}...") # First match is enough return True return False def clean_entry_content(content): """ Remove invalid characters from RSS content. """ cleaned = re.sub(BAD_CHARS_REGEX, '', content) return cleaned def generate_watch_guid(watch): """ Generate a unique GUID for a watch RSS entry. """ return f"{watch['uuid']}/{watch.last_changed}" def generate_watch_diff_content(watch, dates, rss_content_format, datastore): """ Generate HTML diff content for a watch given its history dates. Returns tuple of (content, watch_label). Args: watch: The watch object dates: List of history snapshot dates rss_content_format: Format for RSS content (html or text) datastore: The ChangeDetectionStore instance Returns: Tuple of (content, watch_label) - the rendered HTML content and watch label """ from changedetectionio import diff # Same logic as watch-overview.html if datastore.data['settings']['application']['ui'].get('use_page_title_in_list') or watch.get('use_page_title_in_list'): watch_label = watch.label else: watch_label = watch.get('url') try: html_diff = diff.render_diff( previous_version_file_contents=watch.get_history_snapshot(timestamp=dates[-2]), newest_version_file_contents=watch.get_history_snapshot(timestamp=dates[-1]), include_equal=False ) requested_output_format = datastore.data['settings']['application'].get('rss_content_format') url, html_diff, n_title = apply_service_tweaks(url='', n_body=html_diff, n_title=None, requested_output_format=requested_output_format) except FileNotFoundError as e: html_diff = f"History snapshot file for watch {watch.get('uuid')}@{watch.last_changed} - '{watch.get('title')} not found." # @note: We use

 because nearly all RSS readers render only HTML (Thunderbird for example cant do just plaintext)
    rss_template = "{{watch_label}} had a change.\n\n{{html_diff}}\n"
    if 'html' in rss_content_format:
        rss_template = "\n{{watch_label}}
\n{{html_diff}}\n\n"

    content = jinja_render(template_str=rss_template, watch_label=watch_label, html_diff=html_diff, watch_url=watch.link)

    # Out of range chars could also break feedgen
    if scan_invalid_chars_in_rss(content):
        content = clean_entry_content(content)

    return content, watch_label