| #!/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 |
| |
| 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) |
| |
| def MinifyScript(script): |
| """Remove C-style comments and line breaks from script. |
| Note: statements must be ';' terminated, and not depending on newline""" |
| # Regex adapted from http://ostermiller.org/findcomment.html. |
| MULTILINE_COMMENT_RE = re.compile(r'/\*.*?\*/', re.DOTALL | re.MULTILINE) |
| SINGLELINE_COMMENT_RE = re.compile(r'//.*', re.MULTILINE) |
| # Remove C-style comments from JS. |
| script = re.sub(MULTILINE_COMMENT_RE, '', script) |
| script = re.sub(SINGLELINE_COMMENT_RE, '', script) |
| # Remove line breaks. |
| script = script.translate(None, '\r\n') |
| return script |
| |
| return MinifyScript(''.join(lines)) |
| |
| |
| def InjectScript(content, content_type, script_to_inject): |
| """Inject |script_to_inject| into |content| if |content_type| is 'text/html'. |
| |
| Inject |script_to_inject| into |content| immediately after <head>, <html> or |
| <!doctype html>, if one of them is found. Otherwise, inject at the beginning. |
| |
| Returns: |
| content, already_injected |
| |content| is the new content if script is injected, otherwise the original. |
| |already_injected| indicates if |script_to_inject| is already in |content|. |
| """ |
| already_injected = False |
| if content_type and content_type == 'text/html': |
| already_injected = not content or script_to_inject in content |
| if not already_injected: |
| def InsertScriptAfter(matchobj): |
| return '%s<script>%s</script>' % (matchobj.group(0), script_to_inject) |
| |
| content, is_injected = HEAD_RE.subn(InsertScriptAfter, content, 1) |
| if not is_injected: |
| content, is_injected = HTML_RE.subn(InsertScriptAfter, content, 1) |
| if not is_injected: |
| content, is_injected = DOCTYPE_RE.subn(InsertScriptAfter, content, 1) |
| if not is_injected: |
| content = '<script>%s</script>%s' % (script_to_inject, content) |
| logging.warning('Inject at the very beginning, because no tag of ' |
| '<head>, <html> or <!doctype html> is found.') |
| return content, already_injected |
