Fix docs

changedetectionio/__init__.py

@@ -2,7 +2,7 @@
 
 # Read more https://github.com/dgtlmoon/changedetection.io/wiki
 
-__version__ = '0.50.26'
+__version__ = '0.50.29'
 
 from changedetectionio.strtobool import strtobool
 from json.decoder import JSONDecodeError

changedetectionio/blueprint/rss/blueprint.py

@@ -1,5 +1,6 @@
 
 from changedetectionio.jinja2_custom import render as jinja_render
+from changedetectionio.notification.handler import apply_service_tweaks
 from changedetectionio.store import ChangeDetectionStore
 from feedgen.feed import FeedGenerator
 from flask import Blueprint, make_response, request, url_for, redirect
@@ -120,9 +121,13 @@ def construct_blueprint(datastore: ChangeDetectionStore):
                     html_diff = diff.render_diff(previous_version_file_contents=watch.get_history_snapshot(dates[-2]),
                                                  newest_version_file_contents=watch.get_history_snapshot(dates[-1]),
                                                  include_equal=False,
-                                                 line_feed_sep="<br>",
-                                                 html_colour=html_colour_enable
+                                                 line_feed_sep="<br>"
                                                  )
+
+
+                    requested_output_format = 'htmlcolor' if html_colour_enable else 'html'
+                    html_diff = 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."
 

changedetectionio/diff.py

@@ -1,8 +1,21 @@
 import difflib
 from typing import List, Iterator, Union
 
-REMOVED_STYLE = "background-color: #fadad7; color: #b30000;"
-ADDED_STYLE = "background-color: #eaf2c2; color: #406619;"
+HTML_REMOVED_STYLE = "background-color: #fadad7; color: #b30000;"
+HTML_ADDED_STYLE = "background-color: #eaf2c2; color: #406619;"
+
+# These get set to html or telegram type or discord compatible or whatever in handler.py
+REMOVED_PLACEMARKER_OPEN = '<<<removed_PLACEMARKER_OPEN'
+REMOVED_PLACEMARKER_CLOSED = '<<<removed_PLACEMARKER_CLOSED'
+
+ADDED_PLACEMARKER_OPEN = '<<<added_PLACEMARKER_OPEN'
+ADDED_PLACEMARKER_CLOSED = '<<<added_PLACEMARKER_CLOSED'
+
+CHANGED_PLACEMARKER_OPEN = '<<<changed_PLACEMARKER_OPEN'
+CHANGED_PLACEMARKER_CLOSED = '<<<changed_PLACEMARKER_CLOSED'
+
+CHANGED_INTO_PLACEMARKER_OPEN = '<<<changed_into_PLACEMARKER_OPEN'
+CHANGED_INTO_PLACEMARKER_CLOSED = '<<<changed_into_PLACEMARKER_CLOSED'
 
 def same_slicer(lst: List[str], start: int, end: int) -> List[str]:
     """Return a slice of the list, or a single element if start == end."""
@@ -15,8 +28,7 @@ def customSequenceMatcher(
     include_removed: bool = True,
     include_added: bool = True,
     include_replaced: bool = True,
-    include_change_type_prefix: bool = True,
-    html_colour: bool = False
+    include_change_type_prefix: bool = True
 ) -> Iterator[List[str]]:
     """
     Compare two sequences and yield differences based on specified parameters.
@@ -29,8 +41,6 @@ def customSequenceMatcher(
         include_added (bool): Include added parts
         include_replaced (bool): Include replaced parts
         include_change_type_prefix (bool): Add prefixes to indicate change types
-        html_colour (bool): Use HTML background colors for differences
-
     Yields:
         List[str]: Differences between sequences
     """
@@ -42,22 +52,22 @@ def customSequenceMatcher(
         if include_equal and tag == 'equal':
             yield before[alo:ahi]
         elif include_removed and tag == 'delete':
-            if html_colour:
-                yield [f'<span style="{REMOVED_STYLE}">{line}</span>' for line in same_slicer(before, alo, ahi)]
+            if include_change_type_prefix:
+                yield [f'{REMOVED_PLACEMARKER_OPEN}{line}{REMOVED_PLACEMARKER_CLOSED}' for line in same_slicer(before, alo, ahi)]
             else:
-                yield [f"(removed) {line}" for line in same_slicer(before, alo, ahi)] if include_change_type_prefix else same_slicer(before, alo, ahi)
+                yield same_slicer(before, alo, ahi)
         elif include_replaced and tag == 'replace':
-            if html_colour:
-                yield [f'<span style="{REMOVED_STYLE}">{line}</span>' for line in same_slicer(before, alo, ahi)] + \
-                      [f'<span style="{ADDED_STYLE}">{line}</span>' for line in same_slicer(after, blo, bhi)]
+            if include_change_type_prefix:
+                yield [f'{CHANGED_PLACEMARKER_OPEN}{line}{CHANGED_PLACEMARKER_CLOSED}' for line in same_slicer(before, alo, ahi)] + \
+                      [f'{CHANGED_INTO_PLACEMARKER_OPEN}{line}{CHANGED_INTO_PLACEMARKER_CLOSED}' for line in same_slicer(after, blo, bhi)]
             else:
-                yield [f"(changed) {line}" for line in same_slicer(before, alo, ahi)] + \
-                      [f"(into) {line}" for line in same_slicer(after, blo, bhi)] if include_change_type_prefix else same_slicer(before, alo, ahi) + same_slicer(after, blo, bhi)
+                yield same_slicer(before, alo, ahi) + same_slicer(after, blo, bhi)
         elif include_added and tag == 'insert':
-            if html_colour:
-                yield [f'<span style="{ADDED_STYLE}">{line}</span>' for line in same_slicer(after, blo, bhi)]
+            if include_change_type_prefix:
+                yield [f'{ADDED_PLACEMARKER_OPEN}{line}{ADDED_PLACEMARKER_CLOSED}' for line in same_slicer(after, blo, bhi)]
             else:
-                yield [f"(added) {line}" for line in same_slicer(after, blo, bhi)] if include_change_type_prefix else same_slicer(after, blo, bhi)
+                yield same_slicer(after, blo, bhi)
+
 
 def render_diff(
     previous_version_file_contents: str,
@@ -68,8 +78,7 @@ def render_diff(
     include_replaced: bool = True,
     line_feed_sep: str = "\n",
     include_change_type_prefix: bool = True,
-    patch_format: bool = False,
-    html_colour: bool = False
+    patch_format: bool = False
 ) -> str:
     """
     Render the difference between two file contents.
@@ -84,8 +93,6 @@ def render_diff(
         line_feed_sep (str): Separator for lines in output
         include_change_type_prefix (bool): Add prefixes to indicate change types
         patch_format (bool): Use patch format for output
-        html_colour (bool): Use HTML background colors for differences
-
     Returns:
         str: Rendered difference
     """
@@ -103,8 +110,7 @@ def render_diff(
         include_removed=include_removed,
         include_added=include_added,
         include_replaced=include_replaced,
-        include_change_type_prefix=include_change_type_prefix,
-        html_colour=html_colour
+        include_change_type_prefix=include_change_type_prefix
     )
 
     def flatten(lst: List[Union[str, List[str]]]) -> str:

changedetectionio/forms.py

@@ -761,6 +761,14 @@ class commonSettingsForm(Form):
     scheduler_timezone_default = StringField("Default timezone for watch check scheduler", render_kw={"list": "timezones"}, validators=[validateTimeZoneName()])
     webdriver_delay = IntegerField('Wait seconds before extracting text', validators=[validators.Optional(), validators.NumberRange(min=1, message="Should contain one or more seconds")])
 
+# Not true anymore but keep the validate_ hook for future use, we convert color tags
+#    def validate_notification_urls(self, field):
+#        """Validate that HTML Color format is not used with Telegram"""
+#        if self.notification_format.data == 'HTML Color' and field.data:
+#            for url in field.data:
+#                if url and ('tgram://' in url or 'discord://' in url or 'discord.com/api/webhooks' in url):
+#                    raise ValidationError('HTML Color format is not supported by Telegram and Discord. Please choose another Notification Format (Plain Text, HTML, or Markdown to HTML).')
+
 
 class importForm(Form):
     from . import processors

changedetectionio/html_tools.py

@@ -185,8 +185,21 @@ def xpath_filter(xpath_filter, html_content, append_pretty_line_formatting=False
     tree = html.fromstring(bytes(html_content, encoding='utf-8'), parser=parser)
     html_block = ""
 
-    r = elementpath.select(tree, xpath_filter.strip(), namespaces={'re': 'http://exslt.org/regular-expressions'}, parser=XPath3Parser)
-    #@note: //title/text() wont work where <title>CDATA..
+    # Build namespace map for XPath queries
+    namespaces = {'re': 'http://exslt.org/regular-expressions'}
+
+    # Handle default namespace in documents (common in RSS/Atom feeds, but can occur in any XML)
+    # XPath spec: unprefixed element names have no namespace, not the default namespace
+    # Solution: Register the default namespace with empty string prefix in elementpath
+    # This is primarily for RSS/Atom feeds but works for any XML with default namespace
+    if hasattr(tree, 'nsmap') and tree.nsmap and None in tree.nsmap:
+        # Register the default namespace with empty string prefix for elementpath
+        # This allows //title to match elements in the default namespace
+        namespaces[''] = tree.nsmap[None]
+
+    r = elementpath.select(tree, xpath_filter.strip(), namespaces=namespaces, parser=XPath3Parser)
+    #@note: //title/text() now works with default namespaces (fixed by registering '' prefix)
+    #@note: //title/text() wont work where <title>CDATA.. (use cdata_in_document_to_text first)
 
     if type(r) != list:
         r = [r]
@@ -221,8 +234,19 @@ def xpath1_filter(xpath_filter, html_content, append_pretty_line_formatting=Fals
     tree = html.fromstring(bytes(html_content, encoding='utf-8'), parser=parser)
     html_block = ""
 
-    r = tree.xpath(xpath_filter.strip(), namespaces={'re': 'http://exslt.org/regular-expressions'})
-    #@note: //title/text() wont work where <title>CDATA..
+    # Build namespace map for XPath queries
+    namespaces = {'re': 'http://exslt.org/regular-expressions'}
+
+    # NOTE: lxml's native xpath() does NOT support empty string prefix for default namespace
+    # For documents with default namespace (RSS/Atom feeds), users must use:
+    #   - local-name(): //*[local-name()='title']/text()
+    #   - Or use xpath_filter (not xpath1_filter) which supports default namespaces
+    # XPath spec: unprefixed element names have no namespace, not the default namespace
+
+    r = tree.xpath(xpath_filter.strip(), namespaces=namespaces)
+    #@note: xpath1 (lxml) does NOT automatically handle default namespaces
+    #@note: Use //*[local-name()='element'] or switch to xpath_filter for default namespace support
+    #@note: //title/text() wont work where <title>CDATA.. (use cdata_in_document_to_text first)
 
     for element in r:
         # When there's more than 1 match, then add the suffix to separate each line
@@ -408,6 +432,9 @@ def strip_ignore_text(content, wordlist, mode="content"):
     ignored_lines = []
 
     for k in wordlist:
+        # Skip empty strings to avoid matching everything
+        if not k or not k.strip():
+            continue
         # Is it a regex?
         res = re.search(PERL_STYLE_REGEX, k, re.IGNORECASE)
         if res:

changedetectionio/jinja2_custom/__init__.py

@@ -9,6 +9,7 @@ from .safe_jinja import (
     JINJA2_MAX_RETURN_PAYLOAD_SIZE,
     DEFAULT_JINJA2_EXTENSIONS,
 )
+from .plugins.regex import regex_replace
 
 __all__ = [
     'TimeExtension',
@@ -17,4 +18,5 @@ __all__ = [
     'create_jinja_env',
     'JINJA2_MAX_RETURN_PAYLOAD_SIZE',
     'DEFAULT_JINJA2_EXTENSIONS',
+    'regex_replace',
 ]

changedetectionio/jinja2_custom/plugins/__init__.py

@@ -0,0 +1,6 @@
+"""
+Jinja2 custom filter plugins for changedetection.io
+"""
+from .regex import regex_replace
+
+__all__ = ['regex_replace']

changedetectionio/jinja2_custom/plugins/regex.py

@@ -0,0 +1,98 @@
+"""
+Regex filter plugin for Jinja2 templates.
+
+Provides regex_replace filter for pattern-based string replacements in templates.
+"""
+import re
+import signal
+from loguru import logger
+
+
+def regex_replace(value: str, pattern: str, replacement: str = '', count: int = 0) -> str:
+    """
+    Replace occurrences of a regex pattern in a string.
+
+    Security: Protected against ReDoS (Regular Expression Denial of Service) attacks:
+    - Limits input value size to prevent excessive processing
+    - Uses timeout mechanism to prevent runaway regex operations
+    - Validates pattern complexity to prevent catastrophic backtracking
+
+    Args:
+        value: The input string to perform replacements on
+        pattern: The regex pattern to search for
+        replacement: The replacement string (default: '')
+        count: Maximum number of replacements (0 = replace all, default: 0)
+
+    Returns:
+        String with replacements applied, or original value on error
+
+    Example:
+        {{ "hello world" | regex_replace("world", "universe") }}
+        {{ diff | regex_replace("<td>([^<]+)</td><td>([^<]+)</td>", "Label1: \\1\\nLabel2: \\2") }}
+
+    Security limits:
+        - Maximum input size: 10MB
+        - Maximum pattern length: 500 characters
+        - Operation timeout: 10 seconds
+        - Dangerous nested quantifier patterns are rejected
+    """
+    # Security limits
+    MAX_INPUT_SIZE = 1024 * 1024 * 10 # 10MB max input size
+    MAX_PATTERN_LENGTH = 500  # Maximum regex pattern length
+    REGEX_TIMEOUT_SECONDS = 10  # Maximum time for regex operation
+
+    # Validate input sizes
+    value_str = str(value)
+    if len(value_str) > MAX_INPUT_SIZE:
+        logger.warning(f"regex_replace: Input too large ({len(value_str)} bytes), truncating")
+        value_str = value_str[:MAX_INPUT_SIZE]
+
+    if len(pattern) > MAX_PATTERN_LENGTH:
+        logger.warning(f"regex_replace: Pattern too long ({len(pattern)} chars), rejecting")
+        return value_str
+
+    # Check for potentially dangerous patterns (basic checks)
+    # Nested quantifiers like (a+)+ can cause catastrophic backtracking
+    dangerous_patterns = [
+        r'\([^)]*\+[^)]*\)\+',  # (x+)+
+        r'\([^)]*\*[^)]*\)\+',  # (x*)+
+        r'\([^)]*\+[^)]*\)\*',  # (x+)*
+        r'\([^)]*\*[^)]*\)\*',  # (x*)*
+    ]
+
+    for dangerous in dangerous_patterns:
+        if re.search(dangerous, pattern):
+            logger.warning(f"regex_replace: Potentially dangerous pattern detected: {pattern}")
+            return value_str
+
+    def timeout_handler(signum, frame):
+        raise TimeoutError("Regex operation timed out")
+
+    try:
+        # Set up timeout for regex operation (Unix-like systems only)
+        # This prevents ReDoS attacks
+        old_handler = None
+        if hasattr(signal, 'SIGALRM'):
+            old_handler = signal.signal(signal.SIGALRM, timeout_handler)
+            signal.alarm(REGEX_TIMEOUT_SECONDS)
+
+        try:
+            result = re.sub(pattern, replacement, value_str, count=count)
+        finally:
+            # Cancel the alarm
+            if hasattr(signal, 'SIGALRM'):
+                signal.alarm(0)
+                if old_handler is not None:
+                    signal.signal(signal.SIGALRM, old_handler)
+
+        return result
+
+    except TimeoutError:
+        logger.error(f"regex_replace: Regex operation timed out - possible ReDoS attack. Pattern: {pattern}")
+        return value_str
+    except re.error as e:
+        logger.warning(f"regex_replace: Invalid regex pattern: {e}")
+        return value_str
+    except Exception as e:
+        logger.error(f"regex_replace: Unexpected error: {e}")
+        return value_str

changedetectionio/jinja2_custom/safe_jinja.py

@@ -8,13 +8,13 @@ import jinja2.sandbox
 import typing as t
 import os
 from .extensions.TimeExtension import TimeExtension
+from .plugins import regex_replace
 
 JINJA2_MAX_RETURN_PAYLOAD_SIZE = 1024 * int(os.getenv("JINJA2_MAX_RETURN_PAYLOAD_SIZE_KB", 1024 * 10))
 
 # Default extensions - can be overridden in create_jinja_env()
 DEFAULT_JINJA2_EXTENSIONS = [TimeExtension]
 
-
 def create_jinja_env(extensions=None, **kwargs) -> jinja2.sandbox.ImmutableSandboxedEnvironment:
     """
     Create a sandboxed Jinja2 environment with our custom extensions and default timezone.
@@ -38,6 +38,9 @@ def create_jinja_env(extensions=None, **kwargs) -> jinja2.sandbox.ImmutableSandb
     default_timezone = os.getenv('TZ', 'UTC').strip()
     jinja2_env.default_timezone = default_timezone
 
+    # Register custom filters
+    jinja2_env.filters['regex_replace'] = regex_replace
+
     return jinja2_env
 
 

changedetectionio/model/Watch.py

@@ -9,6 +9,7 @@ from pathlib import Path
 from loguru import logger
 
 from .. import jinja2_custom as safe_jinja
+from ..diff import ADDED_PLACEMARKER_OPEN
 from ..html_tools import TRANSLATE_WHITESPACE_TABLE
 
 # Allowable protocols, protects against javascript: etc
@@ -89,9 +90,8 @@ class model(watch_base):
                 ready_url = jinja_render(template_str=url)
             except Exception as e:
                 logger.critical(f"Invalid URL template for: '{url}' - {str(e)}")
-                from flask import (
-                    flash, Markup, url_for
-                )
+                from flask import flash, url_for
+                from markupsafe import Markup
                 message = Markup('<a href="{}#general">The URL {} is invalid and cannot be used, click to edit</a>'.format(
                     url_for('ui.ui_edit.edit_page', uuid=self.get('uuid')), self.get('url', '')))
                 flash(message, 'error')

changedetectionio/notification/__init__.py

@@ -1,6 +1,5 @@
 from changedetectionio.model import default_notification_format_for_watch
 
-ult_notification_format_for_watch = 'System default'
 default_notification_format = 'HTML Color'
 default_notification_body = '{{watch_url}} had a change.\n---\n{{diff}}\n---\n'
 default_notification_title = 'ChangeDetection.io Notification - {{watch_url}}'
@@ -8,10 +7,10 @@ default_notification_title = 'ChangeDetection.io Notification - {{watch_url}}'
 # The values (markdown etc) are from apprise NotifyFormat,
 # But to avoid importing the whole heavy module just use the same strings here.
 valid_notification_formats = {
-    'Text': 'text',
-    'Markdown': 'markdown',
+    'Plain Text': 'text',
     'HTML': 'html',
     'HTML Color': 'htmlcolor',
+    'Markdown to HTML': 'markdown',
     # Used only for editing a watch (not for global)
     default_notification_format_for_watch: default_notification_format_for_watch
 }

changedetectionio/notification/apprise_plugin/custom_handlers.py

@@ -70,6 +70,7 @@ def apprise_http_custom_handler(
     title: str,
     notify_type: str,
     meta: dict,
+    body_format: str = None,
     *args,
     **kwargs,
 ) -> bool:

changedetectionio/notification/apprise_plugin/discord.py

@@ -0,0 +1,286 @@
+"""
+Custom Discord plugin for changedetection.io
+Extends Apprise's Discord plugin to support custom colored embeds for removed/added content
+"""
+from apprise.plugins.discord import NotifyDiscord
+from apprise.decorators import notify
+from apprise.common import NotifyFormat
+from loguru import logger
+
+# Import placeholders from changedetection's diff module
+from ...diff import (
+    REMOVED_PLACEMARKER_OPEN,
+    REMOVED_PLACEMARKER_CLOSED,
+    ADDED_PLACEMARKER_OPEN,
+    ADDED_PLACEMARKER_CLOSED,
+    CHANGED_PLACEMARKER_OPEN,
+    CHANGED_PLACEMARKER_CLOSED,
+    CHANGED_INTO_PLACEMARKER_OPEN,
+    CHANGED_INTO_PLACEMARKER_CLOSED,
+)
+
+# Discord embed sidebar colors for different change types
+DISCORD_COLOR_UNCHANGED = 8421504   # Gray (#808080)
+DISCORD_COLOR_REMOVED = 16711680    # Red (#FF0000)
+DISCORD_COLOR_ADDED = 65280         # Green (#00FF00)
+DISCORD_COLOR_CHANGED = 16753920    # Orange (#FFA500)
+DISCORD_COLOR_CHANGED_INTO = 3447003  # Blue (#5865F2 - Discord blue)
+DISCORD_COLOR_WARNING = 16776960    # Yellow (#FFFF00)
+
+
+class NotifyDiscordCustom(NotifyDiscord):
+    """
+    Custom Discord notification handler that supports multiple colored embeds
+    for showing removed (red) and added (green) content separately.
+    """
+
+    def send(self, body, title="", notify_type=None, attach=None, **kwargs):
+        """
+        Override send method to create custom embeds with red/green colors
+        for removed/added content when placeholders are present.
+        """
+
+        # Check if body contains our diff placeholders
+        has_removed = REMOVED_PLACEMARKER_OPEN in body
+        has_added = ADDED_PLACEMARKER_OPEN in body
+        has_changed = CHANGED_PLACEMARKER_OPEN in body
+        has_changed_into = CHANGED_INTO_PLACEMARKER_OPEN in body
+
+        # If we have diff placeholders and we're in markdown/html format, create custom embeds
+        if (has_removed or has_added or has_changed or has_changed_into) and self.notify_format in (NotifyFormat.MARKDOWN, NotifyFormat.HTML):
+            return self._send_with_colored_embeds(body, title, notify_type, attach, **kwargs)
+
+        # Otherwise, use the parent class's default behavior
+        return super().send(body, title, notify_type, attach, **kwargs)
+
+    def _send_with_colored_embeds(self, body, title, notify_type, attach, **kwargs):
+        """
+        Send Discord message with embeds in the original diff order.
+        Preserves the sequence: unchanged -> removed -> added -> unchanged, etc.
+        """
+        from datetime import datetime, timezone
+
+        payload = {
+            "tts": self.tts,
+            "wait": self.tts is False,
+        }
+
+        if self.flags:
+            payload["flags"] = self.flags
+
+        # Acquire image_url
+        image_url = self.image_url(notify_type)
+
+        if self.avatar and (image_url or self.avatar_url):
+            payload["avatar_url"] = self.avatar_url if self.avatar_url else image_url
+
+        if self.user:
+            payload["username"] = self.user
+
+        # Associate our thread_id with our message
+        params = {"thread_id": self.thread_id} if self.thread_id else None
+
+        # Build embeds array preserving order
+        embeds = []
+
+        # Add title as plain bold text in message content (not an embed)
+        if title:
+            payload["content"] = f"**{title}**"
+
+        # Parse the body into ordered chunks
+        chunks = self._parse_body_into_chunks(body)
+
+        # Discord limits:
+        # - Max 10 embeds per message
+        # - Max 6000 characters total across all embeds
+        # - Max 4096 characters per embed description
+        max_embeds = 10
+        max_total_chars = 6000
+        max_embed_description = 4096
+
+        # All 10 embed slots are available for content
+        max_content_embeds = max_embeds
+
+        # Start character count
+        total_chars = 0
+
+        # Create embeds from chunks in order (no titles, just color coding)
+        for chunk_type, content in chunks:
+            if not content.strip():
+                continue
+
+            # Truncate individual embed description if needed
+            if len(content) > max_embed_description:
+                content = content[:max_embed_description - 3] + "..."
+
+            # Check if we're approaching the embed count limit
+            # We need room for the warning embed, so stop at max_content_embeds - 1
+            current_content_embeds = len(embeds)
+            if current_content_embeds >= max_content_embeds - 1:
+                # Add a truncation notice (this will be the 10th embed)
+                embeds.append({
+                    "description": "⚠️ Content truncated (Discord 10 embed limit reached) - Tip: Select 'Plain Text' or 'HTML' format for longer diffs",
+                    "color": DISCORD_COLOR_WARNING,
+                })
+                break
+
+            # Check if adding this embed would exceed total character limit
+            if total_chars + len(content) > max_total_chars:
+                # Add a truncation notice
+                remaining_chars = max_total_chars - total_chars
+                if remaining_chars > 100:
+                    # Add partial content if we have room
+                    truncated_content = content[:remaining_chars - 100] + "..."
+                    embeds.append({
+                        "description": truncated_content,
+                        "color": (DISCORD_COLOR_UNCHANGED if chunk_type == "unchanged"
+                                 else DISCORD_COLOR_REMOVED if chunk_type == "removed"
+                                 else DISCORD_COLOR_ADDED),
+                    })
+                embeds.append({
+                    "description": "⚠️ Content truncated (Discord 6000 char limit reached)\nTip: Select 'Plain Text' or 'HTML' format for longer diffs",
+                    "color": DISCORD_COLOR_WARNING,
+                })
+                break
+
+            if chunk_type == "unchanged":
+                embeds.append({
+                    "description": content,
+                    "color": DISCORD_COLOR_UNCHANGED,
+                })
+            elif chunk_type == "removed":
+                embeds.append({
+                    "description": content,
+                    "color": DISCORD_COLOR_REMOVED,
+                })
+            elif chunk_type == "added":
+                embeds.append({
+                    "description": content,
+                    "color": DISCORD_COLOR_ADDED,
+                })
+            elif chunk_type == "changed":
+                # Changed (old value) - use orange to distinguish from pure removal
+                embeds.append({
+                    "description": content,
+                    "color": DISCORD_COLOR_CHANGED,
+                })
+            elif chunk_type == "changed_into":
+                # Changed into (new value) - use blue to distinguish from pure addition
+                embeds.append({
+                    "description": content,
+                    "color": DISCORD_COLOR_CHANGED_INTO,
+                })
+
+            total_chars += len(content)
+
+        if embeds:
+            payload["embeds"] = embeds
+
+        # Send the payload using parent's _send method
+        if not self._send(payload, params=params):
+            return False
+
+        # Handle attachments if present
+        if attach and self.attachment_support:
+            payload.update({
+                "tts": False,
+                "wait": True,
+            })
+            payload.pop("embeds", None)
+            payload.pop("content", None)
+            payload.pop("allow_mentions", None)
+
+            for attachment in attach:
+                self.logger.info(f"Posting Discord Attachment {attachment.name}")
+                if not self._send(payload, params=params, attach=attachment):
+                    return False
+
+        return True
+
+    def _parse_body_into_chunks(self, body):
+        """
+        Parse the body into ordered chunks of (type, content) tuples.
+        Types: "unchanged", "removed", "added", "changed", "changed_into"
+        Preserves the original order of the diff.
+        """
+        chunks = []
+        position = 0
+
+        while position < len(body):
+            # Find the next marker
+            next_removed = body.find(REMOVED_PLACEMARKER_OPEN, position)
+            next_added = body.find(ADDED_PLACEMARKER_OPEN, position)
+            next_changed = body.find(CHANGED_PLACEMARKER_OPEN, position)
+            next_changed_into = body.find(CHANGED_INTO_PLACEMARKER_OPEN, position)
+
+            # Determine which marker comes first
+            if next_removed == -1 and next_added == -1 and next_changed == -1 and next_changed_into == -1:
+                # No more markers, rest is unchanged
+                if position < len(body):
+                    chunks.append(("unchanged", body[position:]))
+                break
+
+            # Find the earliest marker
+            next_marker_pos = None
+            next_marker_type = None
+
+            # Compare all marker positions to find the earliest
+            markers = []
+            if next_removed != -1:
+                markers.append((next_removed, "removed"))
+            if next_added != -1:
+                markers.append((next_added, "added"))
+            if next_changed != -1:
+                markers.append((next_changed, "changed"))
+            if next_changed_into != -1:
+                markers.append((next_changed_into, "changed_into"))
+
+            if markers:
+                next_marker_pos, next_marker_type = min(markers, key=lambda x: x[0])
+
+            # Add unchanged content before the marker
+            if next_marker_pos > position:
+                chunks.append(("unchanged", body[position:next_marker_pos]))
+
+            # Find the closing marker
+            if next_marker_type == "removed":
+                open_marker = REMOVED_PLACEMARKER_OPEN
+                close_marker = REMOVED_PLACEMARKER_CLOSED
+            elif next_marker_type == "added":
+                open_marker = ADDED_PLACEMARKER_OPEN
+                close_marker = ADDED_PLACEMARKER_CLOSED
+            elif next_marker_type == "changed":
+                open_marker = CHANGED_PLACEMARKER_OPEN
+                close_marker = CHANGED_PLACEMARKER_CLOSED
+            else:  # changed_into
+                open_marker = CHANGED_INTO_PLACEMARKER_OPEN
+                close_marker = CHANGED_INTO_PLACEMARKER_CLOSED
+
+            close_pos = body.find(close_marker, next_marker_pos)
+
+            if close_pos == -1:
+                # No closing marker, take rest as this type
+                content = body[next_marker_pos + len(open_marker):]
+                chunks.append((next_marker_type, content))
+                break
+            else:
+                # Extract content between markers
+                content = body[next_marker_pos + len(open_marker):close_pos]
+                chunks.append((next_marker_type, content))
+                position = close_pos + len(close_marker)
+
+        return chunks
+
+
+# Register the custom Discord handler with Apprise
+# This will override the built-in discord:// handler
+@notify(on="discord")
+def discord_custom_wrapper(body, title, notify_type, meta, body_format=None, *args, **kwargs):
+    """
+    Wrapper function to make the custom Discord handler work with Apprise's decorator system.
+    Note: This decorator approach may not work for overriding built-in plugins.
+    The class-based approach above is the proper way to extend NotifyDiscord.
+    """
+    logger.info("Custom Discord handler called")
+    # This is here for potential future use with decorator-based registration
+    return True

changedetectionio/notification/handler.py

@@ -3,7 +3,12 @@ import time
 import apprise
 from apprise import NotifyFormat
 from loguru import logger
+from urllib.parse import urlparse
 from .apprise_plugin.assets import apprise_asset, APPRISE_AVATAR_URL
+from .apprise_plugin.custom_handlers import SUPPORTED_HTTP_METHODS
+from ..diff import HTML_REMOVED_STYLE, REMOVED_PLACEMARKER_OPEN, REMOVED_PLACEMARKER_CLOSED, ADDED_PLACEMARKER_OPEN, HTML_ADDED_STYLE, \
+    ADDED_PLACEMARKER_CLOSED, CHANGED_INTO_PLACEMARKER_OPEN, CHANGED_INTO_PLACEMARKER_CLOSED, CHANGED_PLACEMARKER_OPEN, \
+    CHANGED_PLACEMARKER_CLOSED
 from ..notification_service import NotificationContextData
 
 
@@ -51,30 +56,156 @@ def notification_format_align_with_apprise(n_format : str):
     """
     Correctly align changedetection's formats with apprise's formats
     Probably these are the same - but good to be sure.
+    These set the expected OUTPUT format type
     :param n_format:
     :return:
     """
 
     if n_format.lower().startswith('html'):
         # Apprise only knows 'html' not 'htmlcolor' etc, which shouldnt matter here
-        n_format = NotifyFormat.HTML
+        n_format = NotifyFormat.HTML.value
     elif n_format.lower().startswith('markdown'):
         # probably the same but just to be safe
-        n_format = NotifyFormat.MARKDOWN
+        n_format = NotifyFormat.MARKDOWN.value
     elif n_format.lower().startswith('text'):
         # probably the same but just to be safe
-        n_format = NotifyFormat.TEXT
+        n_format = NotifyFormat.TEXT.value
     else:
-        n_format = NotifyFormat.TEXT
+        n_format = NotifyFormat.TEXT.value
+
+    return n_format
+
+
+def apply_service_tweaks(url, n_body, n_title, requested_output_format):
+
+    # Re 323 - Limit discord length to their 2000 char limit total or it wont send.
+    # Because different notifications may require different pre-processing, run each sequentially :(
+    # 2000 bytes minus -
+    #     200 bytes for the overhead of the _entire_ json payload, 200 bytes for {tts, wait, content} etc headers
+    #     Length of URL - Incase they specify a longer custom avatar_url
+
+    if not n_body or not n_body.strip():
+        return url, n_body, n_title
+
+    # So if no avatar_url is specified, add one so it can be correctly calculated into the total payload
+    parsed = urlparse(url)
+    k = '?' if not parsed.query else '&'
+    if url and not 'avatar_url' in url \
+            and not url.startswith('mail') \
+            and not url.startswith('post') \
+            and not url.startswith('get') \
+            and not url.startswith('delete') \
+            and not url.startswith('put'):
+        url += k + f"avatar_url={APPRISE_AVATAR_URL}"
+
+    if url.startswith('tgram://'):
+        # Telegram only supports a limit subset of HTML, remove the '<br>' we place in.
+        # re https://github.com/dgtlmoon/changedetection.io/issues/555
+        # @todo re-use an existing library we have already imported to strip all non-allowed tags
+        n_body = n_body.replace('<br>', '\n')
+        n_body = n_body.replace('</br>', '\n')
+
+        # Use strikethrough for removed content, bold for added content
+        n_body = n_body.replace(REMOVED_PLACEMARKER_OPEN, '<s>')
+        n_body = n_body.replace(REMOVED_PLACEMARKER_CLOSED, '</s>')
+        n_body = n_body.replace(ADDED_PLACEMARKER_OPEN, '<b>')
+        n_body = n_body.replace(ADDED_PLACEMARKER_CLOSED, '</b>')
+        # Handle changed/replaced lines (old → new)
+        n_body = n_body.replace(CHANGED_PLACEMARKER_OPEN, '<s>')
+        n_body = n_body.replace(CHANGED_PLACEMARKER_CLOSED, '</s>')
+        n_body = n_body.replace(CHANGED_INTO_PLACEMARKER_OPEN, '<b>')
+        n_body = n_body.replace(CHANGED_INTO_PLACEMARKER_CLOSED, '</b>')
+
+        # real limit is 4096, but minus some for extra metadata
+        payload_max_size = 3600
+        body_limit = max(0, payload_max_size - len(n_title))
+        n_title = n_title[0:payload_max_size]
+        n_body = n_body[0:body_limit]
+
+    elif (url.startswith('discord://') or url.startswith('https://discordapp.com/api/webhooks')
+          or url.startswith('https://discord.com/api'))\
+            and 'html' in requested_output_format:
+        # Discord doesn't support HTML, replace <br> with newlines
+        n_body = n_body.strip().replace('<br>', '\n')
+        n_body = n_body.replace('</br>', '\n')
+
+        # Don't replace placeholders or truncate here - let the custom Discord plugin handle it
+        # The plugin will use embeds (6000 char limit across all embeds) if placeholders are present,
+        # or plain content (2000 char limit) otherwise
+
+        # Only do placeholder replacement if NOT using htmlcolor (which triggers embeds in custom plugin)
+        if requested_output_format == 'html':
+            # No diff placeholders, use Discord markdown for any other formatting
+            # Use Discord markdown: strikethrough for removed, bold for added
+            n_body = n_body.replace(REMOVED_PLACEMARKER_OPEN, '~~')
+            n_body = n_body.replace(REMOVED_PLACEMARKER_CLOSED, '~~')
+            n_body = n_body.replace(ADDED_PLACEMARKER_OPEN, '**')
+            n_body = n_body.replace(ADDED_PLACEMARKER_CLOSED, '**')
+            # Handle changed/replaced lines (old → new)
+            n_body = n_body.replace(CHANGED_PLACEMARKER_OPEN, '~~')
+            n_body = n_body.replace(CHANGED_PLACEMARKER_CLOSED, '~~')
+            n_body = n_body.replace(CHANGED_INTO_PLACEMARKER_OPEN, '**')
+            n_body = n_body.replace(CHANGED_INTO_PLACEMARKER_CLOSED, '**')
+
+            # Apply 2000 char limit for plain content
+            payload_max_size = 1700
+            body_limit = max(0, payload_max_size - len(n_title))
+            n_title = n_title[0:payload_max_size]
+            n_body = n_body[0:body_limit]
+        # else: our custom Discord plugin will convert any placeholders left over into embeds with color bars
+
+    # Is not discord/tgram and they want htmlcolor
+    elif requested_output_format == 'htmlcolor':
+        n_body = n_body.replace(REMOVED_PLACEMARKER_OPEN, f'<span style="{HTML_REMOVED_STYLE}">')
+        n_body = n_body.replace(REMOVED_PLACEMARKER_CLOSED, f'</span>')
+        n_body = n_body.replace(ADDED_PLACEMARKER_OPEN, f'<span style="{HTML_ADDED_STYLE}">')
+        n_body = n_body.replace(ADDED_PLACEMARKER_CLOSED, f'</span>')
+        # Handle changed/replaced lines (old → new)
+        n_body = n_body.replace(CHANGED_PLACEMARKER_OPEN, f'<span style="{HTML_REMOVED_STYLE}">')
+        n_body = n_body.replace(CHANGED_PLACEMARKER_CLOSED, f'</span>')
+        n_body = n_body.replace(CHANGED_INTO_PLACEMARKER_OPEN, f'<span style="{HTML_ADDED_STYLE}">')
+        n_body = n_body.replace(CHANGED_INTO_PLACEMARKER_CLOSED, f'</span>')
+        n_body = n_body.replace("\n", '<br>')
+    elif requested_output_format == 'html':
+        n_body = n_body.replace(REMOVED_PLACEMARKER_OPEN, '(removed) ')
+        n_body = n_body.replace(REMOVED_PLACEMARKER_CLOSED, '')
+        n_body = n_body.replace(ADDED_PLACEMARKER_OPEN, '(added) ')
+        n_body = n_body.replace(ADDED_PLACEMARKER_CLOSED, '')
+        n_body = n_body.replace(CHANGED_PLACEMARKER_OPEN, f'(changed) ')
+        n_body = n_body.replace(CHANGED_PLACEMARKER_CLOSED, f'')
+        n_body = n_body.replace(CHANGED_INTO_PLACEMARKER_OPEN, f'(into) ')
+        n_body = n_body.replace(CHANGED_INTO_PLACEMARKER_CLOSED, f'')
+        n_body = n_body.replace("\n", '<br>')
+
+    else: #plaintext etc default
+        n_body = n_body.replace(REMOVED_PLACEMARKER_OPEN, '(removed) ')
+        n_body = n_body.replace(REMOVED_PLACEMARKER_CLOSED, '')
+        n_body = n_body.replace(ADDED_PLACEMARKER_OPEN, '(added) ')
+        n_body = n_body.replace(ADDED_PLACEMARKER_CLOSED, '')
+        n_body = n_body.replace(CHANGED_PLACEMARKER_OPEN, f'(changed) ')
+        n_body = n_body.replace(CHANGED_PLACEMARKER_CLOSED, f'')
+        n_body = n_body.replace(CHANGED_INTO_PLACEMARKER_OPEN, f'(into) ')
+        n_body = n_body.replace(CHANGED_INTO_PLACEMARKER_CLOSED, f'')
+
+    return url, n_body, n_title
 
-    # Must be str for apprise notify body_format
-    return str(n_format)
 
 def process_notification(n_object: NotificationContextData, datastore):
     from changedetectionio.jinja2_custom import render as jinja_render
     from . import default_notification_format_for_watch, default_notification_format, valid_notification_formats
     # be sure its registered
     from .apprise_plugin.custom_handlers import apprise_http_custom_handler
+    # Register custom Discord plugin
+    from .apprise_plugin.discord import NotifyDiscordCustom
+
+    # Create list of custom handler protocols (both http and https versions)
+    custom_handler_protocols = [f"{method}://" for method in SUPPORTED_HTTP_METHODS]
+    custom_handler_protocols += [f"{method}s://" for method in SUPPORTED_HTTP_METHODS]
+
+    has_custom_handler = any(
+        url.startswith(tuple(custom_handler_protocols))
+        for url in n_object['notification_urls']
+    )
 
     if not isinstance(n_object, NotificationContextData):
         raise TypeError(f"Expected NotificationContextData, got {type(n_object)}")
@@ -86,20 +217,27 @@ def process_notification(n_object: NotificationContextData, datastore):
     # Insert variables into the notification content
     notification_parameters = create_notification_parameters(n_object, datastore)
 
-    n_format = valid_notification_formats.get(
+    requested_output_format = valid_notification_formats.get(
         n_object.get('notification_format', default_notification_format),
         valid_notification_formats[default_notification_format],
     )
 
     # If we arrived with 'System default' then look it up
-    if n_format == default_notification_format_for_watch and datastore.data['settings']['application'].get('notification_format') != default_notification_format_for_watch:
+    if requested_output_format == default_notification_format_for_watch and datastore.data['settings']['application'].get('notification_format') != default_notification_format_for_watch:
         # Initially text or whatever
-        n_format = datastore.data['settings']['application'].get('notification_format', valid_notification_formats[default_notification_format]).lower()
+        requested_output_format = datastore.data['settings']['application'].get('notification_format', valid_notification_formats[default_notification_format]).lower()
 
-    n_format = notification_format_align_with_apprise(n_format=n_format)
+    requested_output_format_original = requested_output_format
+
+    requested_output_format = notification_format_align_with_apprise(n_format=requested_output_format)
 
     logger.trace(f"Complete notification body including Jinja and placeholders calculated in  {time.time() - now:.2f}s")
 
+    # If we have custom handlers, use invalid format to prevent conversion
+    # Otherwise use the proper format
+    if has_custom_handler:
+        input_format = 'raw-no-convert'
+
     # https://github.com/caronc/apprise/wiki/Development_LogCapture
     # Anything higher than or equal to WARNING (which covers things like Connection errors)
     # raise it as an exception
@@ -111,11 +249,19 @@ def process_notification(n_object: NotificationContextData, datastore):
 
     apobj = apprise.Apprise(debug=True, asset=apprise_asset)
 
+    # Override Apprise's built-in Discord plugin with our custom one
+    # This allows us to use colored embeds for diff content
+    # First remove the built-in discord plugin, then add our custom one
+    apprise.plugins.N_MGR.remove('discord')
+    apprise.plugins.N_MGR.add(NotifyDiscordCustom, schemas='discord')
+
     if not n_object.get('notification_urls'):
         return None
 
     with apprise.LogCapture(level=apprise.logging.DEBUG) as logs:
         for url in n_object['notification_urls']:
+            parsed_url = urlparse(url)
+            prefix_add_to_url = '?' if not parsed_url.query else '&'
 
             # Get the notification body from datastore
             n_body = jinja_render(template_str=n_object.get('notification_body', ''), **notification_parameters)
@@ -123,8 +269,31 @@ def process_notification(n_object: NotificationContextData, datastore):
             if n_object.get('markup_text_to_html'):
                 n_body = markup_text_links_to_html(body=n_body)
 
-            if n_format == str(NotifyFormat.HTML):
-                n_body = n_body.replace("\n", '<br>')
+            # This actually means we request "Markdown to HTML"
+            if requested_output_format == NotifyFormat.MARKDOWN.value:
+                output_format = NotifyFormat.HTML.value
+                input_format = NotifyFormat.MARKDOWN.value
+                if not 'format=' in url.lower():
+                    url = f"{url}{prefix_add_to_url}format={output_format}"
+
+            # Deviation from apprise.
+            # No conversion, its like they want to send raw HTML but we add linebreaks
+            elif requested_output_format == NotifyFormat.HTML.value:
+                # same in and out means apprise wont try to convert
+                input_format = output_format = NotifyFormat.HTML.value
+                if not 'format=' in url.lower():
+                    url = f"{url}{prefix_add_to_url}format={output_format}"
+
+            else:
+                # Nothing to be done, leave it as plaintext
+                # `body_format` Tell apprise what format the INPUT is in
+                # &format= in URL Tell apprise what format the OUTPUT should be in (it can convert between)
+                input_format = output_format = NotifyFormat.TEXT.value
+                if not 'format=' in url.lower():
+                    url = f"{url}{prefix_add_to_url}format={output_format}"
+
+            if has_custom_handler:
+                input_format='raw-no-convert'
 
             n_title = jinja_render(template_str=n_object.get('notification_title', ''), **notification_parameters)
 
@@ -140,74 +309,28 @@ def process_notification(n_object: NotificationContextData, datastore):
             logger.info(f">> Process Notification: AppRise notifying {url}")
             url = jinja_render(template_str=url, **notification_parameters)
 
-            # Re 323 - Limit discord length to their 2000 char limit total or it wont send.
-            # Because different notifications may require different pre-processing, run each sequentially :(
-            # 2000 bytes minus -
-            #     200 bytes for the overhead of the _entire_ json payload, 200 bytes for {tts, wait, content} etc headers
-            #     Length of URL - Incase they specify a longer custom avatar_url
-
-            # So if no avatar_url is specified, add one so it can be correctly calculated into the total payload
-            k = '?' if not '?' in url else '&'
-            if not 'avatar_url' in url \
-                    and not url.startswith('mail') \
-                    and not url.startswith('post') \
-                    and not url.startswith('get') \
-                    and not url.startswith('delete') \
-                    and not url.startswith('put'):
-                url += k + f"avatar_url={APPRISE_AVATAR_URL}"
-
-            if url.startswith('tgram://'):
-                # Telegram only supports a limit subset of HTML, remove the '<br>' we place in.
-                # re https://github.com/dgtlmoon/changedetection.io/issues/555
-                # @todo re-use an existing library we have already imported to strip all non-allowed tags
-                n_body = n_body.replace('<br>', '\n')
-                n_body = n_body.replace('</br>', '\n')
-                # real limit is 4096, but minus some for extra metadata
-                payload_max_size = 3600
-                body_limit = max(0, payload_max_size - len(n_title))
-                n_title = n_title[0:payload_max_size]
-                n_body = n_body[0:body_limit]
-
-            elif url.startswith('discord://') or url.startswith('https://discordapp.com/api/webhooks') or url.startswith(
-                    'https://discord.com/api'):
-                # real limit is 2000, but minus some for extra metadata
-                payload_max_size = 1700
-                body_limit = max(0, payload_max_size - len(n_title))
-                n_title = n_title[0:payload_max_size]
-                n_body = n_body[0:body_limit]
-
-            elif url.startswith('mailto'):
-                # Apprise will default to HTML, so we need to override it
-                # So that whats' generated in n_body is in line with what is going to be sent.
-                # https://github.com/caronc/apprise/issues/633#issuecomment-1191449321
-                if not 'format=' in url and (n_format == 'Text' or n_format == 'Markdown'):
-                    prefix = '?' if not '?' in url else '&'
-                    # Apprise format is lowercase text https://github.com/caronc/apprise/issues/633
-                    n_format = n_format.lower()
-                    url = f"{url}{prefix}format={n_format}"
-                # If n_format == HTML, then apprise email should default to text/html and we should be sending HTML only
+            (url, n_body, n_title) = apply_service_tweaks(url=url, n_body=n_body, n_title=n_title, requested_output_format=requested_output_format_original)
 
             apobj.add(url)
 
             sent_objs.append({'title': n_title,
                               'body': n_body,
-                              'url': url,
-                              'body_format': n_format})
+                              'url': url})
 
-        # Blast off the notifications tht are set in .add()
         apobj.notify(
             title=n_title,
             body=n_body,
-            body_format=n_format,
+            # `body_format` Tell apprise what format the INPUT is in
+            # &format= in URL Tell apprise what format the OUTPUT should be in (it can convert between)
+            body_format=input_format,
             # False is not an option for AppRise, must be type None
             attach=n_object.get('screenshot', None)
         )
 
-
         # Returns empty string if nothing found, multi-line string otherwise
         log_value = logs.getvalue()
 
-        if log_value and 'WARNING' in log_value or 'ERROR' in log_value:
+        if log_value and ('WARNING' in log_value or 'ERROR' in log_value):
             logger.critical(log_value)
             raise Exception(log_value)
 

changedetectionio/notification_service.py

@@ -92,7 +92,6 @@ class NotificationService:
         if n_object.get('notification_format') == default_notification_format_for_watch:
             n_object['notification_format'] = self.datastore.data['settings']['application'].get('notification_format')
 
-        html_colour_enable = False
         # HTML needs linebreak, but MarkDown and Text can use a linefeed
         if n_object.get('notification_format') == 'HTML':
             line_feed_sep = "<br>"
@@ -102,7 +101,6 @@ class NotificationService:
             line_feed_sep = "<br>"
             # Snapshot will be plaintext on the disk, convert to some kind of HTML
             snapshot_contents = snapshot_contents.replace('\n', line_feed_sep)
-            html_colour_enable = True
         else:
             line_feed_sep = "\n"
 
@@ -123,11 +121,11 @@ class NotificationService:
 
         n_object.update({
             'current_snapshot': snapshot_contents,
-            'diff': diff.render_diff(prev_snapshot, current_snapshot, line_feed_sep=line_feed_sep, html_colour=html_colour_enable),
-            'diff_added': diff.render_diff(prev_snapshot, current_snapshot, include_removed=False, line_feed_sep=line_feed_sep, html_colour=html_colour_enable),
-            'diff_full': diff.render_diff(prev_snapshot, current_snapshot, include_equal=True, line_feed_sep=line_feed_sep, html_colour=html_colour_enable),
+            'diff': diff.render_diff(prev_snapshot, current_snapshot, line_feed_sep=line_feed_sep),
+            'diff_added': diff.render_diff(prev_snapshot, current_snapshot, include_removed=False, line_feed_sep=line_feed_sep),
+            'diff_full': diff.render_diff(prev_snapshot, current_snapshot, include_equal=True, line_feed_sep=line_feed_sep),
             'diff_patch': diff.render_diff(prev_snapshot, current_snapshot, line_feed_sep=line_feed_sep, patch_format=True),
-            'diff_removed': diff.render_diff(prev_snapshot, current_snapshot, include_added=False, line_feed_sep=line_feed_sep, html_colour=html_colour_enable),
+            'diff_removed': diff.render_diff(prev_snapshot, current_snapshot, include_added=False, line_feed_sep=line_feed_sep),
             'screenshot': watch.get_screenshot() if watch and watch.get('notification_screenshot') else None,
             'triggered_text': triggered_text,
             'uuid': watch.get('uuid') if watch else None,

changedetectionio/processors/text_json_diff/processor.py

@@ -7,6 +7,7 @@ import re
 import urllib3
 
 from changedetectionio.conditions import execute_ruleset_against_all_plugins
+from changedetectionio.diff import ADDED_PLACEMARKER_OPEN
 from changedetectionio.processors import difference_detection_processor
 from changedetectionio.html_tools import PERL_STYLE_REGEX, cdata_in_document_to_text, TRANSLATE_WHITESPACE_TABLE
 from changedetectionio import html_tools, content_fetchers
@@ -324,13 +325,13 @@ class ContentProcessor:
                     append_pretty_line_formatting=not self.watch.is_source_type_url
                 )
 
-            # Raise error if filter returned nothing
-            if not filtered_content.strip():
-                raise FilterNotFoundInResponse(
-                    msg=self.filter_config.include_filters,
-                    screenshot=self.fetcher.screenshot,
-                    xpath_data=self.fetcher.xpath_data
-                )
+        # Raise error if filter returned nothing
+        if not filtered_content.strip():
+            raise FilterNotFoundInResponse(
+                msg=self.filter_config.include_filters,
+                screenshot=self.fetcher.screenshot,
+                xpath_data=self.fetcher.xpath_data
+            )
 
         return filtered_content
 

changedetectionio/static/js/realtime.js

@@ -2,6 +2,13 @@
 
 $(document).ready(function () {
 
+    function reapplyTableStripes() {
+        $('.watch-table tbody tr').each(function(index) {
+            $(this).removeClass('pure-table-odd pure-table-even');
+            $(this).addClass(index % 2 === 0 ? 'pure-table-odd' : 'pure-table-even');
+        });
+    }
+
     function bindSocketHandlerButtonsEvents(socket) {
         $('.ajax-op').on('click.socketHandlerNamespace', function (e) {
             e.preventDefault();
@@ -101,6 +108,7 @@ $(document).ready(function () {
             socket.on('watch_deleted', function (data) {
                 $('tr[data-watch-uuid="' + data.uuid + '"] td').fadeOut(500, function () {
                     $(this).closest('tr').remove();
+                    reapplyTableStripes();
                 });
             });
 

changedetectionio/templates/_common_fields.html

@@ -134,6 +134,12 @@
                                     <p>
                                         URL encoding, use <strong>|urlencode</strong>, for example - <code>gets://hook-website.com/test.php?title={{ '{{ watch_title|urlencode }}' }}</code>
                                     </p>
+                                    <p>
+                                        Regular-expression replace, use <strong>|regex_replace</strong>, for example -   <code>{{ "{{ \"hello world 123\" | regex_replace('[0-9]+', 'no-more-numbers') }}" }}</code>
+                                    </p>
+                                    <p>
+                                        For a complete reference of all Jinja2 built-in filters, users can refer to the <a href="https://jinja.palletsprojects.com/en/3.1.x/templates/#builtin-filters">https://jinja.palletsprojects.com/en/3.1.x/templates/#builtin-filters</a>
+                                    </p>
                                 </div>
                             </div>
                             <div class="pure-control-group">

changedetectionio/tests/smtp/test_notification_smtp.py

@@ -1,14 +1,15 @@
-import json
-import os
 import time
-import re
 from flask import url_for
+from email import message_from_string
+from email.policy import default as email_policy
+
+from changedetectionio.diff import HTML_REMOVED_STYLE, HTML_ADDED_STYLE
 from changedetectionio.tests.util import set_original_response, set_modified_response, set_more_modified_response, live_server_setup, \
     wait_for_all_checks, \
     set_longer_modified_response, delete_all_watches
-from changedetectionio.tests.util import extract_UUID_from_client
+
 import logging
-import base64
+
 
 # NOTE - RELIES ON mailserver as hostname running, see github build recipes
 smtp_test_server = 'mailserver'
@@ -50,7 +51,7 @@ def test_check_notification_email_formats_default_HTML(client, live_server, meas
         url_for("settings.settings_page"),
         data={"application-notification_urls": notification_url,
               "application-notification_title": "fallback-title " + default_notification_title,
-              "application-notification_body": "fallback-body<br> " + default_notification_body,
+              "application-notification_body": "some text\nfallback-body<br> " + default_notification_body,
               "application-notification_format": 'HTML',
               "requests-time_between_check-minutes": 180,
               'application-fetch_backend': "html_requests"},
@@ -77,19 +78,229 @@ def test_check_notification_email_formats_default_HTML(client, live_server, meas
 
     time.sleep(3)
 
-    msg = get_last_message_from_smtp_server()
-    assert len(msg) >= 1
+    msg_raw = get_last_message_from_smtp_server()
+    assert len(msg_raw) >= 1
 
-    # The email should have two bodies, and the text/html part should be <br>
-    assert 'Content-Type: text/plain' in msg
-    assert '(added) So let\'s see what happens.\r\n' in msg  # The plaintext part with \r\n
-    assert 'Content-Type: text/html' in msg
-    assert '(added) So let\'s see what happens.<br>' in msg  # the html part
+    # Parse the email properly using Python's email library
+    msg = message_from_string(msg_raw, policy=email_policy)
+
+    # The email should have two bodies (multipart/alternative with text/plain and text/html)
+    assert msg.is_multipart()
+    assert msg.get_content_type() == 'multipart/alternative'
+
+    # Get the parts
+    parts = list(msg.iter_parts())
+    assert len(parts) == 2
+
+    # First part should be text/plain (the auto-generated plaintext version)
+    text_part = parts[0]
+    assert text_part.get_content_type() == 'text/plain'
+    text_content = text_part.get_content()
+    assert '(added) So let\'s see what happens.\r\n' in text_content  # The plaintext part
+    assert 'fallback-body\r\n' in text_content  # The plaintext part
+
+    # Second part should be text/html
+    html_part = parts[1]
+    assert html_part.get_content_type() == 'text/html'
+    html_content = html_part.get_content()
+    assert 'some text<br>' in html_content  # We converted \n from the notification body
+    assert 'fallback-body<br>' in html_content  # kept the original <br>
+    assert '(added) So let\'s see what happens.<br>' in html_content  # the html part
+    delete_all_watches(client)
+
+
+def test_check_notification_plaintext_format(client, live_server, measure_memory_usage):
+    set_original_response()
+
+    notification_url = f'mailto://changedetection@{smtp_test_server}:11025/?to=fff@home.com'
+
+    #####################
+    # Set this up for when we remove the notification from the watch, it should fallback with these details
+    res = client.post(
+        url_for("settings.settings_page"),
+        data={"application-notification_urls": notification_url,
+              "application-notification_title": "fallback-title " + default_notification_title,
+              "application-notification_body": "some text\n" + default_notification_body,
+              "application-notification_format": 'Plain Text',
+              "requests-time_between_check-minutes": 180,
+              'application-fetch_backend': "html_requests"},
+        follow_redirects=True
+    )
+
+    assert b"Settings updated." in res.data
+
+    # Add a watch and trigger a HTTP POST
+    test_url = url_for('test_endpoint', _external=True)
+    uuid = client.application.config.get('DATASTORE').add_watch(url=test_url)
+    client.get(url_for("ui.form_watch_checknow"), follow_redirects=True)
+    time.sleep(2)
+
+    set_longer_modified_response()
+    client.get(url_for("ui.form_watch_checknow"), follow_redirects=True)
+    wait_for_all_checks(client)
+
+    time.sleep(3)
+
+    msg_raw = get_last_message_from_smtp_server()
+    assert len(msg_raw) >= 1
+
+    # Parse the email properly using Python's email library
+    msg = message_from_string(msg_raw, policy=email_policy)
+
+    # The email should be plain text only (not multipart)
+    assert not msg.is_multipart()
+    assert msg.get_content_type() == 'text/plain'
+
+    # Get the plain text content
+    text_content = msg.get_content()
+    assert '(added) So let\'s see what happens.\r\n' in text_content  # The plaintext part
+
+    # Should NOT contain HTML
+    assert '<br>' not in text_content  # We should not have HTML in plain text
+    delete_all_watches(client)
+
+
+
+def test_check_notification_html_color_format(client, live_server, measure_memory_usage):
+    set_original_response()
+
+    notification_url = f'mailto://changedetection@{smtp_test_server}:11025/?to=fff@home.com'
+
+    #####################
+    # Set this up for when we remove the notification from the watch, it should fallback with these details
+    res = client.post(
+        url_for("settings.settings_page"),
+        data={"application-notification_urls": notification_url,
+              "application-notification_title": "fallback-title " + default_notification_title,
+              "application-notification_body": "some text\n" + default_notification_body,
+              "application-notification_format": 'HTML Color',
+              "requests-time_between_check-minutes": 180,
+              'application-fetch_backend': "html_requests"},
+        follow_redirects=True
+    )
+
+    assert b"Settings updated." in res.data
+
+    # Add a watch and trigger a HTTP POST
+    test_url = url_for('test_endpoint', _external=True)
+    res = client.post(
+        url_for("ui.ui_views.form_quick_watch_add"),
+        data={"url": test_url, "tags": 'nice one'},
+        follow_redirects=True
+    )
+
+    assert b"Watch added" in res.data
+
+    wait_for_all_checks(client)
+    set_longer_modified_response()
+    time.sleep(2)
+
+    client.get(url_for("ui.form_watch_checknow"), follow_redirects=True)
+    wait_for_all_checks(client)
+
+    time.sleep(3)
+
+    msg_raw = get_last_message_from_smtp_server()
+    assert len(msg_raw) >= 1
+
+    # Parse the email properly using Python's email library
+    msg = message_from_string(msg_raw, policy=email_policy)
+
+    # The email should have two bodies (multipart/alternative with text/plain and text/html)
+    assert msg.is_multipart()
+    assert msg.get_content_type() == 'multipart/alternative'
+
+    # Get the parts
+    parts = list(msg.iter_parts())
+    assert len(parts) == 2
+
+    # First part should be text/plain (the auto-generated plaintext version)
+    text_part = parts[0]
+    assert text_part.get_content_type() == 'text/plain'
+    text_content = text_part.get_content()
+    assert 'So let\'s see what happens.\r\n' in text_content  # The plaintext part
+    assert '(added)' not in text_content # Because apprise only dumb converts the html to text
+
+    # Second part should be text/html with color styling
+    html_part = parts[1]
+    assert html_part.get_content_type() == 'text/html'
+    html_content = html_part.get_content()
+    assert HTML_REMOVED_STYLE in html_content
+    assert HTML_ADDED_STYLE in html_content
+
+    assert 'some text<br>' in html_content
+    delete_all_watches(client)
+
+def test_check_notification_markdown_format(client, live_server, measure_memory_usage):
+    set_original_response()
+
+    notification_url = f'mailto://changedetection@{smtp_test_server}:11025/?to=fff@home.com'
+
+    #####################
+    # Set this up for when we remove the notification from the watch, it should fallback with these details
+    res = client.post(
+        url_for("settings.settings_page"),
+        data={"application-notification_urls": notification_url,
+              "application-notification_title": "fallback-title " + default_notification_title,
+              "application-notification_body": "*header*\n\nsome text\n" + default_notification_body,
+              "application-notification_format": 'Markdown to HTML',
+              "requests-time_between_check-minutes": 180,
+              'application-fetch_backend': "html_requests"},
+        follow_redirects=True
+    )
+
+    assert b"Settings updated." in res.data
+
+    # Add a watch and trigger a HTTP POST
+    test_url = url_for('test_endpoint', _external=True)
+    res = client.post(
+        url_for("ui.ui_views.form_quick_watch_add"),
+        data={"url": test_url, "tags": 'nice one'},
+        follow_redirects=True
+    )
+
+    assert b"Watch added" in res.data
+
+    wait_for_all_checks(client)
+    set_longer_modified_response()
+    time.sleep(2)
+
+    client.get(url_for("ui.form_watch_checknow"), follow_redirects=True)
+    wait_for_all_checks(client)
+
+    time.sleep(3)
+
+    msg_raw = get_last_message_from_smtp_server()
+    assert len(msg_raw) >= 1
+
+    # Parse the email properly using Python's email library
+    msg = message_from_string(msg_raw, policy=email_policy)
+
+    # The email should have two bodies (multipart/alternative with text/plain and text/html)
+    assert msg.is_multipart()
+    assert msg.get_content_type() == 'multipart/alternative'
+
+    # Get the parts
+    parts = list(msg.iter_parts())
+    assert len(parts) == 2
+
+    # First part should be text/plain (the auto-generated plaintext version)
+    text_part = parts[0]
+    assert text_part.get_content_type() == 'text/plain'
+    text_content = text_part.get_content()
+    assert '(added) So let\'s see what happens.\r\n' in text_content  # The plaintext part
+
+
+    # Second part should be text/html and roughly converted from markdown to HTML
+    html_part = parts[1]
+    assert html_part.get_content_type() == 'text/html'
+    html_content = html_part.get_content()
+    assert '<p><em>header</em></p>' in html_content
+    assert '(added) So let\'s see what happens.<br' in html_content
     delete_all_watches(client)
 
 
 def test_check_notification_email_formats_default_Text_override_HTML(client, live_server, measure_memory_usage):
-    ##  live_server_setup(live_server) # Setup on conftest per function
 
     # HTML problems? see this
     # https://github.com/caronc/apprise/issues/633
@@ -115,7 +326,7 @@ def test_check_notification_email_formats_default_Text_override_HTML(client, liv
         data={"application-notification_urls": notification_url,
               "application-notification_title": "fallback-title " + default_notification_title,
               "application-notification_body": notification_body,
-              "application-notification_format": 'Text',
+              "application-notification_format": 'Plain Text',
               "requests-time_between_check-minutes": 180,
               'application-fetch_backend': "html_requests"},
         follow_redirects=True
@@ -139,15 +350,21 @@ def test_check_notification_email_formats_default_Text_override_HTML(client, liv
     wait_for_all_checks(client)
 
     time.sleep(3)
-    msg = get_last_message_from_smtp_server()
-    assert len(msg) >= 1
+    msg_raw = get_last_message_from_smtp_server()
+    assert len(msg_raw) >= 1
     #    with open('/tmp/m.txt', 'w') as f:
-    #        f.write(msg)
+    #        f.write(msg_raw)
+
+    # Parse the email properly using Python's email library
+    msg = message_from_string(msg_raw, policy=email_policy)
 
     # The email should not have two bodies, should be TEXT only
+    assert not msg.is_multipart()
+    assert msg.get_content_type() == 'text/plain'
 
-    assert 'Content-Type: text/plain' in msg
-    assert '(added) So let\'s see what happens.\r\n' in msg  # The plaintext part with \r\n
+    # Get the plain text content
+    text_content = msg.get_content()
+    assert '(added) So let\'s see what happens.\r\n' in text_content  # The plaintext part
 
     set_original_response()
     # Now override as HTML format
@@ -164,18 +381,34 @@ def test_check_notification_email_formats_default_Text_override_HTML(client, liv
     wait_for_all_checks(client)
 
     time.sleep(3)
-    msg = get_last_message_from_smtp_server()
-    assert len(msg) >= 1
+    msg_raw = get_last_message_from_smtp_server()
+    assert len(msg_raw) >= 1
 
-    # The email should have two bodies, and the text/html part should be <br>
-    assert 'Content-Type: text/plain' in msg
-    assert '(removed) So let\'s see what happens.\r\n' in msg  # The plaintext part with \n
-    assert 'Content-Type: text/html' in msg
-    assert '(removed) So let\'s see what happens.<br>' in msg  # the html part
+    # Parse the email properly using Python's email library
+    msg = message_from_string(msg_raw, policy=email_policy)
+
+    # The email should have two bodies (multipart/alternative)
+    assert msg.is_multipart()
+    assert msg.get_content_type() == 'multipart/alternative'
+
+    # Get the parts
+    parts = list(msg.iter_parts())
+    assert len(parts) == 2
+
+    # First part should be text/plain
+    text_part = parts[0]
+    assert text_part.get_content_type() == 'text/plain'
+    text_content = text_part.get_content()
+    assert '(removed) So let\'s see what happens.\r\n' in text_content  # The plaintext part
+
+    # Second part should be text/html
+    html_part = parts[1]
+    assert html_part.get_content_type() == 'text/html'
+    html_content = html_part.get_content()
+    assert '(removed) So let\'s see what happens.<br>' in html_content  # the html part
 
     # https://github.com/dgtlmoon/changedetection.io/issues/2103
-    assert '<h1>Test</h1>' in msg
-    assert '&lt;' not in msg
-    assert 'Content-Type: text/html' in msg
+    assert '<h1>Test</h1>' in html_content
+    assert '&lt;' not in html_content
 
     delete_all_watches(client)

changedetectionio/tests/test_add_replace_remove_filter.py

@@ -6,6 +6,9 @@ from flask import url_for
 from .util import live_server_setup, wait_for_all_checks, wait_for_notification_endpoint_output, delete_all_watches
 import time
 
+from ..diff import ADDED_PLACEMARKER_OPEN
+
+
 def set_original(excluding=None, add_line=None):
     test_return_data = """<html>
      <body>
@@ -121,6 +124,7 @@ def test_check_add_line_contains_trigger(client, live_server, measure_memory_usa
               "application-notification_body": 'triggered text was -{{triggered_text}}- ### 网站监测 内容更新了 ####',
               # https://github.com/caronc/apprise/wiki/Notify_Custom_JSON#get-parameter-manipulation
               "application-notification_urls": test_notification_url,
+              "application-notification_format": 'Plain Text',
               "application-minutes_between_check": 180,
               "application-fetch_backend": "html_requests"
               },
@@ -174,6 +178,7 @@ def test_check_add_line_contains_trigger(client, live_server, measure_memory_usa
     assert os.path.isfile("test-datastore/notification.txt"), "Notification fired because I can see the output file"
     with open("test-datastore/notification.txt", 'rb') as f:
         response = f.read()
+        assert ADDED_PLACEMARKER_OPEN.encode('utf-8') not in response #  _apply_diff_filtering shouldnt add something here
         assert b'-Oh yes please' in response
         assert '网站监测 内容更新了'.encode('utf-8') in response
 

changedetectionio/tests/test_filter_exist_changes.py

@@ -86,14 +86,16 @@ def test_filter_doesnt_exist_then_exists_should_get_notification(client, live_se
                                                    "Diff Full: {{diff_full}}\n"
                                                    "Diff as Patch: {{diff_patch}}\n"
                                                    ":-)",
-                              "notification_format": "Text"}
+                              "notification_format": 'Plain Text'}
 
     notification_form_data.update({
         "url": test_url,
         "tags": "my tag",
         "title": "my title",
         "headers": "",
-        "include_filters": '.ticket-available',
+        # preprended with extra filter that intentionally doesn't match any entry,
+        # notification should still be sent even if first filter does not match (PR#3516)
+        "include_filters": ".non-matching-selector\n.ticket-available",
         "fetch_backend": "html_requests",
         "time_between_check_use_default": "y"})
 

changedetectionio/tests/test_filter_failure_notification.py

@@ -63,7 +63,7 @@ def run_filter_test(client, live_server, content_filter, app_notification_format
                                        "Diff Full: {{diff_full}}\n"
                                        "Diff as Patch: {{diff_patch}}\n"
                                        ":-)",
-                  "notification_format": "Text",
+                  "notification_format": 'Plain Text',
                   "fetch_backend": "html_requests",
                   "filter_failure_notification_send": 'y',
                   "time_between_check_use_default": "y",
@@ -177,7 +177,7 @@ def test_check_include_filters_failure_notification(client, live_server, measure
     #   #  live_server_setup(live_server) # Setup on conftest per function
     run_filter_test(client=client, live_server=live_server, content_filter='#nope-doesnt-exist', app_notification_format=valid_notification_formats.get('HTML Color'))
     # Check markup send conversion didnt affect plaintext preference
-    run_filter_test(client=client, live_server=live_server, content_filter='#nope-doesnt-exist', app_notification_format=valid_notification_formats.get('Text'))
+    run_filter_test(client=client, live_server=live_server, content_filter='#nope-doesnt-exist', app_notification_format=valid_notification_formats.get('Plain Text'))
 
 def test_check_xpath_filter_failure_notification(client, live_server, measure_memory_usage):
     #   #  live_server_setup(live_server) # Setup on conftest per function

changedetectionio/tests/test_group.py

@@ -195,7 +195,7 @@ def test_group_tag_notification(client, live_server, measure_memory_usage):
                                                    "Diff as Patch: {{diff_patch}}\n"
                                                    ":-)",
                               "notification_screenshot": True,
-                              "notification_format": "Text",
+                              "notification_format": 'Plain Text',
                               "title": "test-tag"}
 
     res = client.post(

changedetectionio/tests/test_jinja2.py

@@ -169,4 +169,161 @@ def test_default_timezone_subtraction(environment):
 
     finalRender = render("{% now '' - 'minutes=11' %}")
 
-    assert finalRender == "Wed, 09 Dec 2015 23:22:01"
+    assert finalRender == "Wed, 09 Dec 2015 23:22:01"
+
+def test_regex_replace_basic():
+    """Test basic regex_replace functionality."""
+
+    # Simple word replacement
+    finalRender = render("{{ 'hello world' | regex_replace('world', 'universe') }}")
+    assert finalRender == "hello universe"
+
+def test_regex_replace_with_groups():
+    """Test regex_replace with capture groups (issue #3501 use case)."""
+
+    # Transform HTML table data as described in the issue
+    template = "{{ '<td>thing</td><td>other</td>' | regex_replace('<td>([^<]+)</td><td>([^<]+)</td>', 'ThingLabel: \\\\1\\nOtherLabel: \\\\2') }}"
+    finalRender = render(template)
+    assert "ThingLabel: thing" in finalRender
+    assert "OtherLabel: other" in finalRender
+
+def test_regex_replace_multiple_matches():
+    """Test regex_replace replacing multiple occurrences."""
+
+    finalRender = render("{{ 'foo bar foo baz' | regex_replace('foo', 'qux') }}")
+    assert finalRender == "qux bar qux baz"
+
+def test_regex_replace_count_parameter():
+    """Test regex_replace with count parameter to limit replacements."""
+
+    finalRender = render("{{ 'foo bar foo baz' | regex_replace('foo', 'qux', 1) }}")
+    assert finalRender == "qux bar foo baz"
+
+def test_regex_replace_empty_replacement():
+    """Test regex_replace with empty replacement (removal)."""
+
+    finalRender = render("{{ 'hello world 123' | regex_replace('[0-9]+', '') }}")
+    assert finalRender == "hello world "
+
+def test_regex_replace_no_match():
+    """Test regex_replace when pattern doesn't match."""
+
+    finalRender = render("{{ 'hello world' | regex_replace('xyz', 'abc') }}")
+    assert finalRender == "hello world"
+
+def test_regex_replace_invalid_regex():
+    """Test regex_replace with invalid regex pattern returns original value."""
+
+    # Invalid regex (unmatched parenthesis)
+    finalRender = render("{{ 'hello world' | regex_replace('(invalid', 'replacement') }}")
+    assert finalRender == "hello world"
+
+def test_regex_replace_special_characters():
+    """Test regex_replace with special regex characters."""
+
+    finalRender = render("{{ 'Price: $50.00' | regex_replace('\\\\$([0-9.]+)', 'USD \\\\1') }}")
+    assert finalRender == "Price: USD 50.00"
+
+def test_regex_replace_multiline():
+    """Test regex_replace on multiline text."""
+
+    template = "{{ 'line1\\nline2\\nline3' | regex_replace('^line', 'row') }}"
+    finalRender = render(template)
+    # By default re.sub doesn't use MULTILINE flag, so only first line matches with ^
+    assert finalRender == "row1\nline2\nline3"
+
+def test_regex_replace_with_notification_context():
+    """Test regex_replace with notification diff variable."""
+
+    # Simulate how it would be used in notifications with diff variable
+    from changedetectionio.notification_service import NotificationContextData
+
+    context = NotificationContextData()
+    context['diff'] = '<td>value1</td><td>value2</td>'
+
+    template = "{{ diff | regex_replace('<td>([^<]+)</td>', '\\\\1 ') }}"
+
+    from changedetectionio.jinja2_custom import create_jinja_env
+    from jinja2 import BaseLoader
+
+    jinja2_env = create_jinja_env(loader=BaseLoader)
+    jinja2_env.globals.update(context)
+    finalRender = jinja2_env.from_string(template).render()
+
+    assert "value1 value2 " in finalRender
+
+def test_regex_replace_security_large_input():
+    """Test regex_replace handles large input safely."""
+
+    # Create a large input string (over 10MB)
+    large_input = "x" * (1024 * 1024 * 10 + 1000)
+    template = "{{ large_input | regex_replace('x', 'y') }}"
+
+    from changedetectionio.jinja2_custom import create_jinja_env
+    from jinja2 import BaseLoader
+
+    jinja2_env = create_jinja_env(loader=BaseLoader)
+    jinja2_env.globals['large_input'] = large_input
+    finalRender = jinja2_env.from_string(template).render()
+
+    # Should be truncated to 10MB
+    assert len(finalRender) == 1024 * 1024 * 10
+
+def test_regex_replace_security_long_pattern():
+    """Test regex_replace rejects very long patterns."""
+
+    # Pattern longer than 500 chars should be rejected
+    long_pattern = "a" * 501
+    finalRender = render("{{ 'test' | regex_replace('" + long_pattern + "', 'replacement') }}")
+
+    # Should return original value when pattern is too long
+    assert finalRender == "test"
+
+def test_regex_replace_security_dangerous_pattern():
+    """Test regex_replace detects and rejects dangerous nested quantifiers."""
+
+    # Patterns that could cause catastrophic backtracking
+    dangerous_patterns = [
+        "(a+)+",
+        "(a*)+",
+        "(a+)*",
+        "(a*)*",
+    ]
+
+    for dangerous in dangerous_patterns:
+        # Create a template with the dangerous pattern
+        # Using single quotes to avoid escaping issues
+        from changedetectionio.jinja2_custom import create_jinja_env
+        from jinja2 import BaseLoader
+
+        jinja2_env = create_jinja_env(loader=BaseLoader)
+        jinja2_env.globals['pattern'] = dangerous
+        template = "{{ 'aaaaaaaaaa' | regex_replace(pattern, 'x') }}"
+        finalRender = jinja2_env.from_string(template).render()
+
+        # Should return original value when dangerous pattern is detected
+        assert finalRender == "aaaaaaaaaa"
+
+def test_regex_replace_security_timeout_protection():
+    """Test that regex_replace has timeout protection (if SIGALRM available)."""
+    import signal
+
+    # Only test on systems that support SIGALRM
+    if not hasattr(signal, 'SIGALRM'):
+        # Skip test on Windows and other systems without SIGALRM
+        return
+
+    # This pattern is known to cause exponential backtracking on certain inputs
+    # but should be caught by our dangerous pattern detector
+    # We're mainly testing that the timeout mechanism works
+
+    from changedetectionio.jinja2_custom import regex_replace
+
+    # Create input that could trigger slow regex
+    test_input = "a" * 50 + "b"
+
+    # This shouldn't take long due to our protections
+    result = regex_replace(test_input, "a+b", "x")
+
+    # Should complete and return a result
+    assert result is not None

changedetectionio/tests/test_jsonpath_jq_selector.py

@@ -2,7 +2,8 @@
 # coding=utf-8
 
 import time
-from flask import url_for, escape
+from flask import url_for
+from markupsafe import escape
 from . util import live_server_setup, wait_for_all_checks, delete_all_watches
 import pytest
 jq_support = True

changedetectionio/tests/test_notification.py

@@ -101,7 +101,7 @@ def test_check_notification(client, live_server, measure_memory_usage):
                                                    "Diff as Patch: {{diff_patch}}\n"
                                                    ":-)",
                               "notification_screenshot": True,
-                              "notification_format": "Text"}
+                              "notification_format": 'Plain Text'}
 
     notification_form_data.update({
         "url": test_url,
@@ -267,7 +267,7 @@ def test_notification_validation(client, live_server, measure_memory_usage):
 #        data={"notification_urls": 'json://localhost/foobar',
 #              "notification_title": "",
 #              "notification_body": "",
-#              "notification_format": "Text",
+#              "notification_format": 'Plain Text',
 #              "url": test_url,
 #              "tag": "my tag",
 #              "title": "my title",
@@ -383,7 +383,7 @@ def test_notification_custom_endpoint_and_jinja2(client, live_server, measure_me
         assert 'second: hello world "space"' in notification_headers.lower()
 
 
-    # Should always be automatically detected as JSON content type even when we set it as 'Text' (default)
+    # Should always be automatically detected as JSON content type even when we set it as 'Plain Text' (default)
     assert os.path.isfile("test-datastore/notification-content-type.txt")
     with open("test-datastore/notification-content-type.txt", 'r') as f:
         assert 'application/json' in f.read()
@@ -485,7 +485,7 @@ def test_global_send_test_notification(client, live_server, measure_memory_usage
 
 def _test_color_notifications(client, notification_body_token):
 
-    from changedetectionio.diff import ADDED_STYLE, REMOVED_STYLE
+    from changedetectionio.diff import HTML_ADDED_STYLE, HTML_REMOVED_STYLE
 
     set_original_response()
 
@@ -533,7 +533,7 @@ def _test_color_notifications(client, notification_body_token):
 
     with open("test-datastore/notification.txt", 'r') as f:
         x = f.read()
-        assert f'<span style="{REMOVED_STYLE}">Which is across multiple lines' in x
+        assert f'<span style="{HTML_REMOVED_STYLE}">Which is across multiple lines' in x
 
 
     client.get(
@@ -541,9 +541,7 @@ def _test_color_notifications(client, notification_body_token):
         follow_redirects=True
     )
 
+# Just checks the format of the colour notifications was correct
 def test_html_color_notifications(client, live_server, measure_memory_usage):
-
-    
     _test_color_notifications(client, '{{diff}}')
     _test_color_notifications(client, '{{diff_full}}')
-    

changedetectionio/tests/test_notification_errors.py

@@ -30,7 +30,7 @@ def test_check_notification_error_handling(client, live_server, measure_memory_u
         data={"notification_urls": f"{broken_notification_url}\r\n{working_notification_url}",
               "notification_title": "xxx",
               "notification_body": "xxxxx",
-              "notification_format": "Text",
+              "notification_format": 'Plain Text',
               "url": test_url,
               "tags": "",
               "title": "",

changedetectionio/tests/test_xpath_default_namespace.py

@@ -0,0 +1,153 @@
+#!/usr/bin/env python3
+"""
+Unit tests for XPath default namespace handling in RSS/Atom feeds.
+Tests the fix for issue where //title/text() returns empty on feeds with default namespaces.
+
+Real-world test data from https://github.com/microsoft/PowerToys/releases.atom
+"""
+
+import sys
+import os
+import pytest
+
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+import html_tools
+
+
+# Real-world Atom feed with default namespace from GitHub PowerToys releases
+# This is the actual format that was failing before the fix
+atom_feed_with_default_ns = """<?xml version="1.0" encoding="UTF-8"?>
+<feed xmlns="http://www.w3.org/2005/Atom" xmlns:media="http://search.yahoo.com/mrss/" xml:lang="en-US">
+  <id>tag:github.com,2008:https://github.com/microsoft/PowerToys/releases</id>
+  <link type="text/html" rel="alternate" href="https://github.com/microsoft/PowerToys/releases"/>
+  <link type="application/atom+xml" rel="self" href="https://github.com/microsoft/PowerToys/releases.atom"/>
+  <title>Release notes from PowerToys</title>
+  <updated>2025-10-23T08:53:12Z</updated>
+  <entry>
+    <id>tag:github.com,2008:Repository/184456251/v0.95.1</id>
+    <updated>2025-10-24T14:20:14Z</updated>
+    <link rel="alternate" type="text/html" href="https://github.com/microsoft/PowerToys/releases/tag/v0.95.1"/>
+    <title>Release 0.95.1</title>
+    <content type="html">&lt;p&gt;This patch release fixes several important stability issues.&lt;/p&gt;</content>
+    <author>
+      <name>Jaylyn-Barbee</name>
+    </author>
+  </entry>
+  <entry>
+    <id>tag:github.com,2008:Repository/184456251/v0.95.0</id>
+    <updated>2025-10-17T12:51:21Z</updated>
+    <link rel="alternate" type="text/html" href="https://github.com/microsoft/PowerToys/releases/tag/v0.95.0"/>
+    <title>Release v0.95.0</title>
+    <content type="html">&lt;p&gt;New features, stability, optimization improvements.&lt;/p&gt;</content>
+    <author>
+      <name>Jaylyn-Barbee</name>
+    </author>
+  </entry>
+</feed>"""
+
+# RSS feed without default namespace
+rss_feed_no_default_ns = """<?xml version="1.0" encoding="UTF-8"?>
+<rss version="2.0">
+  <channel>
+    <title>Channel Title</title>
+    <description>Channel Description</description>
+    <item>
+      <title>Item 1 Title</title>
+      <description>Item 1 Description</description>
+    </item>
+    <item>
+      <title>Item 2 Title</title>
+      <description>Item 2 Description</description>
+    </item>
+  </channel>
+</rss>"""
+
+# RSS 2.0 feed with namespace prefix (not default)
+rss_feed_with_ns_prefix = """<?xml version="1.0" encoding="UTF-8"?>
+<rss xmlns:dc="http://purl.org/dc/elements/1.1/"
+     xmlns:content="http://purl.org/rss/1.0/modules/content/"
+     xmlns:atom="http://www.w3.org/2005/Atom"
+     version="2.0">
+  <channel>
+    <title>Channel Title</title>
+    <atom:link href="http://example.com/feed" rel="self" type="application/rss+xml"/>
+    <item>
+      <title>Item Title</title>
+      <dc:creator>Author Name</dc:creator>
+    </item>
+  </channel>
+</rss>"""
+
+
+class TestXPathDefaultNamespace:
+    """Test XPath queries on feeds with and without default namespaces."""
+
+    def test_atom_feed_simple_xpath_with_xpath_filter(self):
+        """Test that //title/text() works on Atom feed with default namespace using xpath_filter."""
+        result = html_tools.xpath_filter('//title/text()', atom_feed_with_default_ns, is_rss=True)
+        assert 'Release notes from PowerToys' in result
+        assert 'Release 0.95.1' in result
+        assert 'Release v0.95.0' in result
+
+    def test_atom_feed_nested_xpath_with_xpath_filter(self):
+        """Test nested XPath like //entry/title/text() on Atom feed."""
+        result = html_tools.xpath_filter('//entry/title/text()', atom_feed_with_default_ns, is_rss=True)
+        assert 'Release 0.95.1' in result
+        assert 'Release v0.95.0' in result
+        # Should NOT include the feed title
+        assert 'Release notes from PowerToys' not in result
+
+    def test_atom_feed_other_elements_with_xpath_filter(self):
+        """Test that other elements like //updated/text() work on Atom feed."""
+        result = html_tools.xpath_filter('//updated/text()', atom_feed_with_default_ns, is_rss=True)
+        assert '2025-10-23T08:53:12Z' in result
+        assert '2025-10-24T14:20:14Z' in result
+
+    def test_rss_feed_without_namespace(self):
+        """Test that //title/text() works on RSS feed without default namespace."""
+        result = html_tools.xpath_filter('//title/text()', rss_feed_no_default_ns, is_rss=True)
+        assert 'Channel Title' in result
+        assert 'Item 1 Title' in result
+        assert 'Item 2 Title' in result
+
+    def test_rss_feed_nested_xpath(self):
+        """Test nested XPath on RSS feed without default namespace."""
+        result = html_tools.xpath_filter('//item/title/text()', rss_feed_no_default_ns, is_rss=True)
+        assert 'Item 1 Title' in result
+        assert 'Item 2 Title' in result
+        # Should NOT include channel title
+        assert 'Channel Title' not in result
+
+    def test_rss_feed_with_prefixed_namespaces(self):
+        """Test that feeds with namespace prefixes (not default) still work."""
+        result = html_tools.xpath_filter('//title/text()', rss_feed_with_ns_prefix, is_rss=True)
+        assert 'Channel Title' in result
+        assert 'Item Title' in result
+
+    def test_local_name_workaround_still_works(self):
+        """Test that local-name() workaround still works for Atom feeds."""
+        result = html_tools.xpath_filter('//*[local-name()="title"]/text()', atom_feed_with_default_ns, is_rss=True)
+        assert 'Release notes from PowerToys' in result
+        assert 'Release 0.95.1' in result
+
+    def test_xpath1_filter_without_default_namespace(self):
+        """Test xpath1_filter works on RSS without default namespace."""
+        result = html_tools.xpath1_filter('//title/text()', rss_feed_no_default_ns, is_rss=True)
+        assert 'Channel Title' in result
+        assert 'Item 1 Title' in result
+
+    def test_xpath1_filter_with_default_namespace_returns_empty(self):
+        """Test that xpath1_filter returns empty on Atom with default namespace (known limitation)."""
+        result = html_tools.xpath1_filter('//title/text()', atom_feed_with_default_ns, is_rss=True)
+        # xpath1_filter (lxml) doesn't support default namespaces, so this returns empty
+        assert result == ''
+
+    def test_xpath1_filter_local_name_workaround(self):
+        """Test that xpath1_filter works with local-name() workaround on Atom feeds."""
+        result = html_tools.xpath1_filter('//*[local-name()="title"]/text()', atom_feed_with_default_ns, is_rss=True)
+        assert 'Release notes from PowerToys' in result
+        assert 'Release 0.95.1' in result
+
+
+if __name__ == '__main__':
+    pytest.main([__file__, '-v'])

changedetectionio/tests/unit/test_notification_diff.py

@@ -24,18 +24,18 @@ class TestDiffBuilder(unittest.TestCase):
 
         output = output.split("\n")
 
-
-        self.assertIn('(changed) ok', output)
-        self.assertIn('(into) xok', output)
-        self.assertIn('(into) next-x-ok', output)
-        self.assertIn('(added) and something new', output)
+        # Check that placeholders are present (they get replaced in apply_service_tweaks)
+        self.assertTrue(any(diff.CHANGED_PLACEMARKER_OPEN in line and 'ok' in line for line in output))
+        self.assertTrue(any(diff.CHANGED_INTO_PLACEMARKER_OPEN in line and 'xok' in line for line in output))
+        self.assertTrue(any(diff.CHANGED_INTO_PLACEMARKER_OPEN in line and 'next-x-ok' in line for line in output))
+        self.assertTrue(any(diff.ADDED_PLACEMARKER_OPEN in line and 'and something new' in line for line in output))
 
         with open(base_dir + "/test-content/after-2.txt", 'r') as f:
             newest_version_file_contents = f.read()
         output = diff.render_diff(previous_version_file_contents, newest_version_file_contents)
         output = output.split("\n")
-        self.assertIn('(removed) for having learned computerese,', output)
-        self.assertIn('(removed) I continue to examine bits, bytes and words', output)
+        self.assertTrue(any(diff.REMOVED_PLACEMARKER_OPEN in line and 'for having learned computerese,' in line for line in output))
+        self.assertTrue(any(diff.REMOVED_PLACEMARKER_OPEN in line and 'I continue to examine bits, bytes and words' in line for line in output))
 
         #diff_removed
         with open(base_dir + "/test-content/before.txt", 'r') as f:
@@ -45,18 +45,18 @@ class TestDiffBuilder(unittest.TestCase):
             newest_version_file_contents = f.read()
         output = diff.render_diff(previous_version_file_contents, newest_version_file_contents, include_equal=False, include_removed=True, include_added=False)
         output = output.split("\n")
-        self.assertIn('(changed) ok', output)
-        self.assertIn('(into) xok', output)
-        self.assertIn('(into) next-x-ok', output)
-        self.assertNotIn('(added) and something new', output)
+        self.assertTrue(any(diff.CHANGED_PLACEMARKER_OPEN in line and 'ok' in line for line in output))
+        self.assertTrue(any(diff.CHANGED_INTO_PLACEMARKER_OPEN in line and 'xok' in line for line in output))
+        self.assertTrue(any(diff.CHANGED_INTO_PLACEMARKER_OPEN in line and 'next-x-ok' in line for line in output))
+        self.assertFalse(any(diff.ADDED_PLACEMARKER_OPEN in line and 'and something new' in line for line in output))
 
         #diff_removed
         with open(base_dir + "/test-content/after-2.txt", 'r') as f:
             newest_version_file_contents = f.read()
         output = diff.render_diff(previous_version_file_contents, newest_version_file_contents, include_equal=False, include_removed=True, include_added=False)
         output = output.split("\n")
-        self.assertIn('(removed) for having learned computerese,', output)
-        self.assertIn('(removed) I continue to examine bits, bytes and words', output)
+        self.assertTrue(any(diff.REMOVED_PLACEMARKER_OPEN in line and 'for having learned computerese,' in line for line in output))
+        self.assertTrue(any(diff.REMOVED_PLACEMARKER_OPEN in line and 'I continue to examine bits, bytes and words' in line for line in output))
 
     def test_expected_diff_patch_output(self):
         base_dir = os.path.dirname(__file__)

requirements.txt

@@ -10,14 +10,14 @@ flask_restful
 flask_cors # For the Chrome extension to operate
 janus # Thread-safe async/sync queue bridge
 flask_wtf~=1.2
-flask~=2.3
+flask~=3.1
 flask-socketio~=5.5.1
 python-socketio~=5.13.0
 python-engineio~=4.12.3
 inscriptis~=2.2
 pytz
 timeago~=1.0
-validators~=0.21
+validators~=0.35
 
 
 # Set these versions together to avoid a RequestsDependencyWarning
@@ -56,7 +56,7 @@ cryptography==44.0.1
 paho-mqtt!=2.0.*
 
 # Used for CSS filtering, JSON extraction from HTML
-beautifulsoup4>=4.0.0,<=4.13.5
+beautifulsoup4>=4.0.0,<=4.14.2
 
 # XPath filtering, lxml is required by bs4 anyway, but put it here to be safe.
 # #2328 - 5.2.0 and 5.2.1 had extra CPU flag CFLAGS set which was not compatible on older hardware
@@ -66,14 +66,10 @@ lxml >=4.8.0,<6,!=5.2.0,!=5.2.1
 
 # XPath 2.0-3.1 support - 4.2.0 had issues, 4.1.5 stable
 # Consider updating to latest stable version periodically
-elementpath==4.1.5
+elementpath==5.0.4
 
 selenium~=4.31.0
 
-# https://github.com/pallets/werkzeug/issues/2985
-# Maybe related to pytest?
-werkzeug==3.0.6
-
 # Templating, so far just in the URLs but in the future can be for the notifications also
 jinja2~=3.1
 arrow