#!/usr/bin/env python
# Copyright 2013 Google Inc. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""Inject javascript into html page source code."""
import logging
import os
import re
import util
import third_party.jsmin as jsmin
DOCTYPE_RE = re.compile(r'^.{,256}?(<!--.*-->)?.{,256}?<!doctype html>',
re.IGNORECASE | re.DOTALL)
HTML_RE = re.compile(r'^.{,256}?(<!--.*-->)?.{,256}?<html.*?>',
re.IGNORECASE | re.DOTALL)
HEAD_RE = re.compile(r'^.{,256}?(<!--.*-->)?.{,256}?<head.*?>',
re.IGNORECASE | re.DOTALL)
def GetInjectScript(scripts):
"""Loads |scripts| from disk and returns a string of their content."""
lines = []
if scripts:
if not isinstance(scripts, list):
scripts = scripts.split(',')
for script in scripts:
if os.path.exists(script):
with open(script) as f:
lines.extend(f.read())
elif util.resource_exists(script):
lines.extend(util.resource_string(script))
else:
raise Exception('Script does not exist: %s', script)
return jsmin.jsmin(''.join(lines), quote_chars="'\"`")
def _IsHtmlContent(content):
content = content.strip()
return content.startswith('<') and content.endswith('>')
def InjectScript(text_chunks, content_type, script_to_inject):
"""Inject |script_to_inject| into |content| if |content_type| is 'text/html'.
Inject |script_to_inject| into |text_chunks| immediately after <head>,
<html> or <!doctype html>, if one of them is found. Otherwise, inject at
the beginning.
Returns:
text_chunks, already_injected
|text_chunks| is the new content if script is injected, otherwise
the original. If the script was injected, exactly one chunk in
|text_chunks| will have changed.
|just_injected| indicates if |script_to_inject| was just injected in
the content.
"""
if not content_type or content_type != 'text/html':
return text_chunks, False
content = "".join(text_chunks)
if not content or not _IsHtmlContent(content) or script_to_inject in content:
return text_chunks, False
for regexp in (HEAD_RE, HTML_RE, DOCTYPE_RE):
matchobj = regexp.search(content)
if matchobj:
pos = matchobj.end(0)
for i, chunk in enumerate(text_chunks):
if pos <= len(chunk):
result = text_chunks[:]
result[i] = '%s<script>%s</script>%s' % (chunk[0:pos],
script_to_inject,
chunk[pos:])
return result, True
pos -= len(chunk)
result = text_chunks[:]
result[0] = '<script>%s</script>%s' % (script_to_inject,
text_chunks[0])
logging.warning('Inject at the very beginning, because no tag of '
'<head>, <html> or <!doctype html> is found.')
return result, True