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changedetection.io/changedetectionio/processors/text_json_diff/processor.py

369 lines
20 KiB

# HTML to TEXT/JSON DIFFERENCE self.fetcher
import hashlib
import json
import os
import re
import urllib3
from changedetectionio.processors import difference_detection_processor
from changedetectionio.html_tools import PERL_STYLE_REGEX, cdata_in_document_to_text
from changedetectionio import html_tools, content_fetchers
from changedetectionio.blueprint.price_data_follower import PRICE_DATA_TRACK_ACCEPT, PRICE_DATA_TRACK_REJECT
from loguru import logger
urllib3.disable_warnings(urllib3.exceptions.InsecureRequestWarning)
name = 'Webpage Text/HTML, JSON and PDF changes'
description = 'Detects all text changes where possible'
json_filter_prefixes = ['json:', 'jq:', 'jqraw:']
class FilterNotFoundInResponse(ValueError):
def __init__(self, msg, screenshot=None, xpath_data=None):
self.screenshot = screenshot
self.xpath_data = xpath_data
ValueError.__init__(self, msg)
class PDFToHTMLToolNotFound(ValueError):
def __init__(self, msg):
ValueError.__init__(self, msg)
# Some common stuff here that can be moved to a base class
# (set_proxy_from_list)
class perform_site_check(difference_detection_processor):
def run_changedetection(self, watch, skip_when_checksum_same=True):
changed_detected = False
html_content = ""
screenshot = False # as bytes
stripped_text_from_html = ""
if not watch:
raise Exception("Watch no longer exists.")
# Unset any existing notification error
update_obj = {'last_notification_error': False, 'last_error': False}
url = watch.link
self.screenshot = self.fetcher.screenshot
self.xpath_data = self.fetcher.xpath_data
# Track the content type
update_obj['content_type'] = self.fetcher.get_all_headers().get('content-type', '').lower()
# Watches added automatically in the queue manager will skip if its the same checksum as the previous run
# Saves a lot of CPU
update_obj['previous_md5_before_filters'] = hashlib.md5(self.fetcher.content.encode('utf-8')).hexdigest()
if skip_when_checksum_same:
if update_obj['previous_md5_before_filters'] == watch.get('previous_md5_before_filters'):
raise content_fetchers.exceptions.checksumFromPreviousCheckWasTheSame()
# Fetching complete, now filters
# @note: I feel like the following should be in a more obvious chain system
# - Check filter text
# - Is the checksum different?
# - Do we convert to JSON?
# https://stackoverflow.com/questions/41817578/basic-method-chaining ?
# return content().textfilter().jsonextract().checksumcompare() ?
is_json = 'application/json' in self.fetcher.get_all_headers().get('content-type', '').lower()
is_html = not is_json
is_rss = False
ctype_header = self.fetcher.get_all_headers().get('content-type', '').lower()
# Go into RSS preprocess for converting CDATA/comment to usable text
if any(substring in ctype_header for substring in ['application/xml', 'application/rss', 'text/xml']):
if '<rss' in self.fetcher.content[:100].lower():
self.fetcher.content = cdata_in_document_to_text(html_content=self.fetcher.content)
is_rss = True
# source: support, basically treat it as plaintext
if watch.is_source_type_url:
is_html = False
is_json = False
inline_pdf = self.fetcher.get_all_headers().get('content-disposition', '') and '%PDF-1' in self.fetcher.content[:10]
if watch.is_pdf or 'application/pdf' in self.fetcher.get_all_headers().get('content-type', '').lower() or inline_pdf:
from shutil import which
tool = os.getenv("PDF_TO_HTML_TOOL", "pdftohtml")
if not which(tool):
raise PDFToHTMLToolNotFound("Command-line `{}` tool was not found in system PATH, was it installed?".format(tool))
import subprocess
proc = subprocess.Popen(
[tool, '-stdout', '-', '-s', 'out.pdf', '-i'],
stdout=subprocess.PIPE,
stdin=subprocess.PIPE)
proc.stdin.write(self.fetcher.raw_content)
proc.stdin.close()
self.fetcher.content = proc.stdout.read().decode('utf-8')
proc.wait(timeout=60)
# Add a little metadata so we know if the file changes (like if an image changes, but the text is the same
# @todo may cause problems with non-UTF8?
metadata = "<p>Added by changedetection.io: Document checksum - {} Filesize - {} bytes</p>".format(
hashlib.md5(self.fetcher.raw_content).hexdigest().upper(),
len(self.fetcher.content))
self.fetcher.content = self.fetcher.content.replace('</body>', metadata + '</body>')
# Better would be if Watch.model could access the global data also
# and then use getattr https://docs.python.org/3/reference/datamodel.html#object.__getitem__
# https://realpython.com/inherit-python-dict/ instead of doing it procedurely
include_filters_from_tags = self.datastore.get_tag_overrides_for_watch(uuid=watch.get('uuid'), attr='include_filters')
# 1845 - remove duplicated filters in both group and watch include filter
include_filters_rule = list(dict.fromkeys(watch.get('include_filters', []) + include_filters_from_tags))
subtractive_selectors = [*self.datastore.get_tag_overrides_for_watch(uuid=watch.get('uuid'), attr='subtractive_selectors'),
*watch.get("subtractive_selectors", []),
*self.datastore.data["settings"]["application"].get("global_subtractive_selectors", [])
]
# Inject a virtual LD+JSON price tracker rule
if watch.get('track_ldjson_price_data', '') == PRICE_DATA_TRACK_ACCEPT:
include_filters_rule += html_tools.LD_JSON_PRODUCT_OFFER_SELECTORS
has_filter_rule = len(include_filters_rule) and len(include_filters_rule[0].strip())
has_subtractive_selectors = len(subtractive_selectors) and len(subtractive_selectors[0].strip())
if is_json and not has_filter_rule:
include_filters_rule.append("json:$")
has_filter_rule = True
if is_json:
# Sort the JSON so we dont get false alerts when the content is just re-ordered
try:
self.fetcher.content = json.dumps(json.loads(self.fetcher.content), sort_keys=True)
except Exception as e:
# Might have just been a snippet, or otherwise bad JSON, continue
pass
if has_filter_rule:
for filter in include_filters_rule:
if any(prefix in filter for prefix in json_filter_prefixes):
stripped_text_from_html += html_tools.extract_json_as_string(content=self.fetcher.content, json_filter=filter)
is_html = False
if is_html or watch.is_source_type_url:
# CSS Filter, extract the HTML that matches and feed that into the existing inscriptis::get_text
self.fetcher.content = html_tools.workarounds_for_obfuscations(self.fetcher.content)
html_content = self.fetcher.content
# If not JSON, and if it's not text/plain..
if 'text/plain' in self.fetcher.get_all_headers().get('content-type', '').lower():
# Don't run get_text or xpath/css filters on plaintext
stripped_text_from_html = html_content
else:
# Does it have some ld+json price data? used for easier monitoring
update_obj['has_ldjson_price_data'] = html_tools.has_ldjson_product_info(self.fetcher.content)
# Then we assume HTML
if has_filter_rule:
html_content = ""
for filter_rule in include_filters_rule:
# For HTML/XML we offer xpath as an option, just start a regular xPath "/.."
if filter_rule[0] == '/' or filter_rule.startswith('xpath:'):
html_content += html_tools.xpath_filter(xpath_filter=filter_rule.replace('xpath:', ''),
html_content=self.fetcher.content,
append_pretty_line_formatting=not watch.is_source_type_url,
is_rss=is_rss)
elif filter_rule.startswith('xpath1:'):
html_content += html_tools.xpath1_filter(xpath_filter=filter_rule.replace('xpath1:', ''),
html_content=self.fetcher.content,
append_pretty_line_formatting=not watch.is_source_type_url,
is_rss=is_rss)
else:
html_content += html_tools.include_filters(include_filters=filter_rule,
html_content=self.fetcher.content,
append_pretty_line_formatting=not watch.is_source_type_url)
if not html_content.strip():
raise FilterNotFoundInResponse(msg=include_filters_rule, screenshot=self.fetcher.screenshot, xpath_data=self.fetcher.xpath_data)
if has_subtractive_selectors:
html_content = html_tools.element_removal(subtractive_selectors, html_content)
if watch.is_source_type_url:
stripped_text_from_html = html_content
else:
# extract text
do_anchor = self.datastore.data["settings"]["application"].get("render_anchor_tag_content", False)
stripped_text_from_html = html_tools.html_to_text(html_content=html_content,
render_anchor_tag_content=do_anchor,
is_rss=is_rss) # 1874 activate the <title workaround hack
if watch.get('trim_text_whitespace'):
stripped_text_from_html = '\n'.join(line.strip() for line in stripped_text_from_html.replace("\n\n", "\n").splitlines())
if watch.get('remove_duplicate_lines'):
stripped_text_from_html = '\n'.join(dict.fromkeys(line.strip() for line in stripped_text_from_html.replace("\n\n", "\n").splitlines()))
if watch.get('sort_text_alphabetically'):
# Note: Because a <p>something</p> will add an extra line feed to signify the paragraph gap
# we end up with 'Some text\n\n', sorting will add all those extra \n at the start, so we remove them here.
stripped_text_from_html = stripped_text_from_html.replace("\n\n", "\n")
stripped_text_from_html = '\n'.join(sorted(stripped_text_from_html.splitlines(), key=lambda x: x.lower()))
# Re #340 - return the content before the 'ignore text' was applied
text_content_before_ignored_filter = stripped_text_from_html.encode('utf-8')
# @todo whitespace coming from missing rtrim()?
# stripped_text_from_html could be based on their preferences, replace the processed text with only that which they want to know about.
# Rewrite's the processing text based on only what diff result they want to see
if watch.has_special_diff_filter_options_set() and len(watch.history.keys()):
# Now the content comes from the diff-parser and not the returned HTTP traffic, so could be some differences
from changedetectionio import diff
# needs to not include (added) etc or it may get used twice
# Replace the processed text with the preferred result
rendered_diff = diff.render_diff(previous_version_file_contents=watch.get_last_fetched_text_before_filters(),
newest_version_file_contents=stripped_text_from_html,
include_equal=False, # not the same lines
include_added=watch.get('filter_text_added', True),
include_removed=watch.get('filter_text_removed', True),
include_replaced=watch.get('filter_text_replaced', True),
line_feed_sep="\n",
include_change_type_prefix=False)
watch.save_last_text_fetched_before_filters(text_content_before_ignored_filter)
if not rendered_diff and stripped_text_from_html:
# We had some content, but no differences were found
# Store our new file as the MD5 so it will trigger in the future
c = hashlib.md5(text_content_before_ignored_filter.translate(None, b'\r\n\t ')).hexdigest()
return False, {'previous_md5': c}, stripped_text_from_html.encode('utf-8'), stripped_text_from_html.encode('utf-8')
else:
stripped_text_from_html = rendered_diff
# Treat pages with no renderable text content as a change? No by default
empty_pages_are_a_change = self.datastore.data['settings']['application'].get('empty_pages_are_a_change', False)
if not is_json and not empty_pages_are_a_change and len(stripped_text_from_html.strip()) == 0:
raise content_fetchers.exceptions.ReplyWithContentButNoText(url=url,
status_code=self.fetcher.get_last_status_code(),
screenshot=self.fetcher.screenshot,
has_filters=has_filter_rule,
html_content=html_content,
xpath_data=self.fetcher.xpath_data
)
# We rely on the actual text in the html output.. many sites have random script vars etc,
# in the future we'll implement other mechanisms.
update_obj["last_check_status"] = self.fetcher.get_last_status_code()
# If there's text to skip
# @todo we could abstract out the get_text() to handle this cleaner
text_to_ignore = watch.get('ignore_text', []) + self.datastore.data['settings']['application'].get('global_ignore_text', [])
if len(text_to_ignore):
stripped_text_from_html = html_tools.strip_ignore_text(stripped_text_from_html, text_to_ignore)
else:
stripped_text_from_html = stripped_text_from_html.encode('utf8')
# 615 Extract text by regex
extract_text = watch.get('extract_text', [])
if len(extract_text) > 0:
regex_matched_output = []
for s_re in extract_text:
# incase they specified something in '/.../x'
if re.search(PERL_STYLE_REGEX, s_re, re.IGNORECASE):
regex = html_tools.perl_style_slash_enclosed_regex_to_options(s_re)
result = re.findall(regex.encode('utf-8'), stripped_text_from_html)
for l in result:
if type(l) is tuple:
# @todo - some formatter option default (between groups)
regex_matched_output += list(l) + [b'\n']
else:
# @todo - some formatter option default (between each ungrouped result)
regex_matched_output += [l] + [b'\n']
else:
# Doesnt look like regex, just hunt for plaintext and return that which matches
# `stripped_text_from_html` will be bytes, so we must encode s_re also to bytes
r = re.compile(re.escape(s_re.encode('utf-8')), re.IGNORECASE)
res = r.findall(stripped_text_from_html)
if res:
for match in res:
regex_matched_output += [match] + [b'\n']
##########################################################
stripped_text_from_html = b''
text_content_before_ignored_filter = b''
if regex_matched_output:
# @todo some formatter for presentation?
stripped_text_from_html = b''.join(regex_matched_output)
text_content_before_ignored_filter = stripped_text_from_html
# Re #133 - if we should strip whitespaces from triggering the change detected comparison
if self.datastore.data['settings']['application'].get('ignore_whitespace', False):
fetched_md5 = hashlib.md5(stripped_text_from_html.translate(None, b'\r\n\t ')).hexdigest()
else:
fetched_md5 = hashlib.md5(stripped_text_from_html).hexdigest()
############ Blocking rules, after checksum #################
blocked = False
trigger_text = watch.get('trigger_text', [])
if len(trigger_text):
# Assume blocked
blocked = True
# Filter and trigger works the same, so reuse it
# It should return the line numbers that match
# Unblock flow if the trigger was found (some text remained after stripped what didnt match)
result = html_tools.strip_ignore_text(content=str(stripped_text_from_html),
wordlist=trigger_text,
mode="line numbers")
# Unblock if the trigger was found
if result:
blocked = False
text_should_not_be_present = watch.get('text_should_not_be_present', [])
if len(text_should_not_be_present):
# If anything matched, then we should block a change from happening
result = html_tools.strip_ignore_text(content=str(stripped_text_from_html),
wordlist=text_should_not_be_present,
mode="line numbers")
if result:
blocked = True
# The main thing that all this at the moment comes down to :)
if watch.get('previous_md5') != fetched_md5:
changed_detected = True
# Looks like something changed, but did it match all the rules?
if blocked:
changed_detected = False
logger.debug(f"Watch UUID {watch.get('uuid')} content check - Previous MD5: {watch.get('previous_md5')}, Fetched MD5 {fetched_md5}")
if changed_detected:
if watch.get('check_unique_lines', False):
has_unique_lines = watch.lines_contain_something_unique_compared_to_history(lines=stripped_text_from_html.splitlines())
# One or more lines? unsure?
if not has_unique_lines:
logger.debug(f"check_unique_lines: UUID {watch.get('uuid')} didnt have anything new setting change_detected=False")
changed_detected = False
else:
logger.debug(f"check_unique_lines: UUID {watch.get('uuid')} had unique content")
# Always record the new checksum
update_obj["previous_md5"] = fetched_md5
# On the first run of a site, watch['previous_md5'] will be None, set it the current one.
if not watch.get('previous_md5'):
watch['previous_md5'] = fetched_md5
return changed_detected, update_obj, text_content_before_ignored_filter, stripped_text_from_html