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#!/usr/bin/python
# Copyright (c) 2011 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be found
# in the LICENSE file.
"""Extracts registration forms from the corresponding HTML files.
Used for extracting forms within HTML files. This script is used in
conjunction with the webforms_aggregator.py script, which aggregates web pages
with fillable forms (i.e registration forms).
The purpose of this script is to extract out all non-form elements that may be
causing parsing errors and timeout issues when running browser_tests.
This script extracts all forms from a HTML file.
If there are multiple forms per downloaded site, multiple files are created
for each form.
Used as a standalone script but assumes that it is run from the directory in
which it is checked into.
Usage: forms_extractor.py [options]
Options:
-l LOG_LEVEL, --log_level=LOG_LEVEL,
LOG_LEVEL: debug, info, warning or error [default: error]
-j, --js extracts javascript elements from web form.
-h, --help show this help message and exit
"""
import glob
import logging
from optparse import OptionParser
import os
import re
import sys
class FormsExtractor(object):
"""Extracts HTML files, leaving only registration forms from the HTML file."""
_HTML_FILES_PATTERN = r'*.html'
_HTML_FILE_PREFIX = r'grabber-'
_FORM_FILE_PREFIX = r'grabber-stripped-'
_REGISTRATION_PAGES_DIR = os.path.join(os.pardir, 'test', 'data', 'autofill',
'heuristics', 'input')
_EXTRACTED_FORMS_DIR = os.path.join(os.pardir, 'test', 'data', 'autofill',
'heuristics', 'input')
logger = logging.getLogger(__name__)
log_handlers = {'StreamHandler': None}
# This pattern is used for retrieving the form location comment located at the
# top of each downloaded HTML file indicating where the form originated from.
_RE_FORM_LOCATION_PATTERN = re.compile(
ur"""
<!--Form\s{1}Location: # Starting of form location comment.
.*? # Any characters (non-greedy).
--> # Ending of the form comment.
""", re.U | re.S | re.I | re.X)
# This pattern is used for removing all script code.
_RE_SCRIPT_PATTERN = re.compile(
ur"""
<script # A new opening '<script' tag.
\b # The end of the word 'script'.
.*? # Any characters (non-greedy).
> # Ending of the (opening) tag: '>'.
.*? # Any characters (non-greedy) between the tags.
</script\s*> # The '</script>' closing tag.
""", re.U | re.S | re.I | re.X)
# This pattern is used for removing all href js code.
_RE_HREF_JS_PATTERN = re.compile(
ur"""
\bhref # The word href and its beginning.
\s*=\s* # The '=' with all whitespace before and after it.
(?P<quote>[\'\"]) # A single or double quote which is captured.
\s*javascript\s*: # The word 'javascript:' with any whitespace possible.
.*? # Any characters (non-greedy) between the quotes.
\1 # The previously captured single or double quote.
""", re.U | re.S | re.I | re.X)
_RE_EVENT_EXPR = (
ur"""
\b # The beginning of a new word.
on\w+? # All words starting with 'on' (non-greedy)
# example: |onmouseover|.
\s*=\s* # The '=' with all whitespace before and after it.
(?P<quote>[\'\"]) # A captured single or double quote.
.*? # Any characters (non-greedy) between the quotes.
\1 # The previously captured single or double quote.
""")
# This pattern is used for removing code with js events, such as |onload|.
# By adding the leading |ur'<[^<>]*?'| and the trailing |'ur'[^<>]*?>'| the
# pattern matches to strings such as '<tr class="nav"
# onmouseover="mOvr1(this);" onmouseout="mOut1(this);">'
_RE_TAG_WITH_EVENTS_PATTERN = re.compile(
ur"""
< # Matches character '<'.
[^<>]*? # Matches any characters except '<' and '>' (non-greedy).""" +
_RE_EVENT_EXPR +
ur"""
[^<>]*? # Matches any characters except '<' and '>' (non-greedy).
> # Matches character '>'.
""", re.U | re.S | re.I | re.X)
# Adds whitespace chars at the end of the matched event. Also match trailing
# whitespaces for JS events. Do not match leading whitespace.
# For example: |< /form>| is invalid HTML and does not exist but |</form >| is
# considered valid HTML.
_RE_EVENT_PATTERN = re.compile(
_RE_EVENT_EXPR + ur'\s*', re.U | re.S | re.I | re.X)
# This pattern is used for finding form elements.
_RE_FORM_PATTERN = re.compile(
ur"""
<form # A new opening '<form' tag.
\b # The end of the word 'form'.
.*? # Any characters (non-greedy).
> # Ending of the (opening) tag: '>'.
.*? # Any characters (non-greedy) between the tags.
</form\s*> # The '</form>' closing tag.
""", re.U | re.S | re.I | re.X)
def __init__(self, input_dir=_REGISTRATION_PAGES_DIR,
output_dir=_EXTRACTED_FORMS_DIR, logging_level=None):
"""Creates a FormsExtractor object.
Args:
input_dir: the directory of HTML files.
output_dir: the directory where the registration form files will be
saved.
logging_level: verbosity level, default is None.
Raises:
IOError exception if input directory doesn't exist.
"""
if logging_level:
if not self.log_handlers['StreamHandler']:
console = logging.StreamHandler()
console.setLevel(logging.DEBUG)
self.log_handlers['StreamHandler'] = console
self.logger.addHandler(console)
self.logger.setLevel(logging_level)
else:
if self.log_handlers['StreamHandler']:
self.logger.removeHandler(self.log_handlers['StreamHandler'])
self.log_handlers['StreamHandler'] = None
self._input_dir = input_dir
self._output_dir = output_dir
if not os.path.isdir(self._input_dir):
error_msg = 'Directory "%s" doesn\'t exist.' % self._input_dir
self.logger.error('Error: %s', error_msg)
raise IOError(error_msg)
if not os.path.isdir(output_dir):
os.makedirs(output_dir)
self._form_location_comment = ''
def _SubstituteAllEvents(self, matchobj):
"""Remove all js events that are present as attributes within a tag.
Args:
matchobj: A regexp |re.MatchObject| containing text that has at least one
event. Example: |<tr class="nav" onmouseover="mOvr1(this);"
onmouseout="mOut1(this);">|.
Returns:
The text containing the tag with all the attributes except for the tags
with events. Example: |<tr class="nav">|.
"""
tag_with_all_attrs = matchobj.group(0)
return self._RE_EVENT_PATTERN.sub('', tag_with_all_attrs)
def Extract(self, strip_js_only):
"""Extracts and saves the extracted registration forms.
Iterates through all the HTML files.
Args:
strip_js_only: If True, only Javascript is stripped from the HTML content.
Otherwise, all non-form elements are stripped.
"""
pathname_pattern = os.path.join(self._input_dir, self._HTML_FILES_PATTERN)
html_files = [f for f in glob.glob(pathname_pattern) if os.path.isfile(f)]
for filename in html_files:
self.logger.info('Stripping file "%s" ...', filename)
with open(filename, 'U') as f:
html_content = self._RE_TAG_WITH_EVENTS_PATTERN.sub(
self._SubstituteAllEvents,
self._RE_HREF_JS_PATTERN.sub(
'', self._RE_SCRIPT_PATTERN.sub('', f.read())))
form_filename = os.path.split(filename)[1] # Path dropped.
form_filename = form_filename.replace(self._HTML_FILE_PREFIX, '', 1)
(form_filename, extension) = os.path.splitext(form_filename)
form_filename = (self._FORM_FILE_PREFIX + form_filename +
'%s' + extension)
form_filename = os.path.join(self._output_dir, form_filename)
if strip_js_only:
form_filename = form_filename % ''
try:
with open(form_filename, 'w') as f:
f.write(html_content)
except IOError as e:
self.logger.error('Error: %s', e)
continue
else: # Remove all non form elements.
match = self._RE_FORM_LOCATION_PATTERN.search(html_content)
if match:
form_location_comment = match.group() + os.linesep
else:
form_location_comment = ''
forms_iterator = self._RE_FORM_PATTERN.finditer(html_content)
for form_number, form_match in enumerate(forms_iterator, start=1):
form_content = form_match.group()
numbered_form_filename = form_filename % form_number
try:
with open(numbered_form_filename, 'w') as f:
f.write(form_location_comment)
f.write(form_content)
except IOError as e:
self.logger.error('Error: %s', e)
continue
self.logger.info('\tFile "%s" extracted SUCCESSFULLY!', filename)
def main():
# Command line options.
parser = OptionParser()
parser.add_option(
'-l', '--log_level', metavar='LOG_LEVEL', default='error',
help='LOG_LEVEL: debug, info, warning or error [default: %default]')
parser.add_option(
'-j', '--js', dest='js', action='store_true', default=False,
help='Removes all javascript elements [default: %default]')
(options, args) = parser.parse_args()
options.log_level = options.log_level.upper()
if options.log_level not in ['DEBUG', 'INFO', 'WARNING', 'ERROR']:
print 'Wrong log_level argument.'
parser.print_help()
sys.exit(1)
options.log_level = getattr(logging, options.log_level)
extractor = FormsExtractor(logging_level=options.log_level)
extractor.Extract(options.js)
if __name__ == '__main__':
main()