Initial source commit to grit-i18n project.

grit/format/html_inline.py

+#!/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.
+
+"""Flattens a HTML file by inlining its external resources.
+
+This is a small script that takes a HTML file, looks for src attributes
+and inlines the specified file, producing one HTML file with no external
+dependencies.
+
+This does not inline anything referenced from an inlined file.
+"""
+
+import os
+import re
+import sys
+import base64
+import mimetypes
+
+from grit.node import base
+
+DIST_DEFAULT = 'chromium'
+DIST_ENV_VAR = 'CHROMIUM_BUILD'
+DIST_SUBSTR = '%DISTRIBUTION%'
+
+# Matches beginning of an "if" block with trailing spaces.
+_BEGIN_IF_BLOCK = re.compile('<if [^>]*?expr="(?P<expression>[^"]*)"[^>]*?>\s*')
+
+# Matches ending of an "if" block with preceding spaces.
+_END_IF_BLOCK = re.compile('\s*</if>')
+
+def ReadFile(input_filename):
+  """Helper function that returns input_filename as a string.
+
+  Args:
+    input_filename: name of file to be read
+
+  Returns:
+    string
+  """
+  f = open(input_filename, 'rb')
+  file_contents = f.read()
+  f.close()
+  return file_contents
+
+def SrcInlineAsDataURL(
+    src_match, base_path, distribution, inlined_files, names_only=False):
+  """regex replace function.
+
+  Takes a regex match for src="filename", attempts to read the file
+  at 'filename' and returns the src attribute with the file inlined
+  as a data URI. If it finds DIST_SUBSTR string in file name, replaces
+  it with distribution.
+
+  Args:
+    src_match: regex match object with 'filename' named capturing group
+    base_path: path that to look for files in
+    distribution: string that should replace DIST_SUBSTR
+    inlined_files: The name of the opened file is appended to this list.
+    names_only: If true, the function will not read the file but just return "".
+                It will still add the filename to |inlined_files|.
+
+  Returns:
+    string
+  """
+  filename = src_match.group('filename')
+
+  if filename.find(':') != -1:
+    # filename is probably a URL, which we don't want to bother inlining
+    return src_match.group(0)
+
+  filename = filename.replace('%DISTRIBUTION%', distribution)
+  filepath = os.path.join(base_path, filename)
+  inlined_files.add(filepath)
+
+  if names_only:
+    return ""
+
+  mimetype = mimetypes.guess_type(filename)[0] or 'text/plain'
+  inline_data = base64.standard_b64encode(ReadFile(filepath))
+
+  prefix = src_match.string[src_match.start():src_match.start('filename')-1]
+  return "%s\"data:%s;base64,%s\"" % (prefix, mimetype, inline_data)
+
+
+class InlinedData:
+  """Helper class holding the results from DoInline().
+
+  Holds the inlined data and the set of filenames of all the inlined
+  files.
+  """
+  def __init__(self, inlined_data, inlined_files):
+    self.inlined_data = inlined_data
+    self.inlined_files = inlined_files
+
+def DoInline(
+    input_filename, grd_node, allow_external_script=False, names_only=False):
+  """Helper function that inlines the resources in a specified file.
+
+  Reads input_filename, finds all the src attributes and attempts to
+  inline the files they are referring to, then returns the result and
+  the set of inlined files.
+
+  Args:
+    input_filename: name of file to read in
+    grd_node: html node from the grd file for this include tag
+    names_only: |nil| will be returned for the inlined contents (faster).
+  Returns:
+    a tuple of the inlined data as a string and the set of filenames
+    of all the inlined files
+  """
+  input_filepath = os.path.dirname(input_filename)
+
+  distribution = DIST_DEFAULT
+  if DIST_ENV_VAR in os.environ.keys():
+    distribution = os.environ[DIST_ENV_VAR]
+    if len(distribution) > 1 and distribution[0] == '_':
+      distribution = distribution[1:].lower()
+
+  # Keep track of all the files we inline.
+  inlined_files = set()
+
+  def SrcReplace(src_match, filepath=input_filepath,
+                 inlined_files=inlined_files):
+    """Helper function to provide SrcInlineAsDataURL with the base file path"""
+    return SrcInlineAsDataURL(
+        src_match, filepath, distribution, inlined_files, names_only=names_only)
+
+  def GetFilepath(src_match):
+    filename = src_match.group('filename')
+
+    if filename.find(':') != -1:
+      # filename is probably a URL, which we don't want to bother inlining
+      return None
+
+    filename = filename.replace('%DISTRIBUTION%', distribution)
+    return os.path.join(input_filepath, filename)
+
+  def IsConditionSatisfied(src_match):
+    expression = src_match.group('expression')
+    return grd_node is None or grd_node.EvaluateCondition(expression)
+
+  def CheckConditionalElements(str):
+    """Helper function to conditionally inline inner elements"""
+    while True:
+      begin_if = _BEGIN_IF_BLOCK.search(str)
+      if begin_if is None:
+        return str
+
+      condition_satisfied = IsConditionSatisfied(begin_if)
+      leading = str[0:begin_if.start()]
+      content_start = begin_if.end()
+
+      # Find matching "if" block end.
+      count = 1
+      pos = begin_if.end()
+      while True:
+        end_if = _END_IF_BLOCK.search(str, pos)
+        if end_if is None:
+          raise Exception('Unmatched <if>')
+
+        next_if = _BEGIN_IF_BLOCK.search(str, pos)
+        if next_if is None or next_if.start() >= end_if.end():
+          count = count - 1
+          if count == 0:
+            break
+          pos = end_if.end()
+        else:
+          count = count + 1
+          pos = next_if.end()
+
+      content = str[content_start:end_if.start()]
+      trailing = str[end_if.end():]
+
+      if condition_satisfied:
+        str = leading + CheckConditionalElements(content) + trailing
+      else:
+        str = leading + trailing
+
+  def InlineFileContents(src_match, pattern, inlined_files=inlined_files):
+    """Helper function to inline external script and css files"""
+    filepath = GetFilepath(src_match)
+    if filepath is None:
+      return src_match.group(0)
+    inlined_files.add(filepath)
+
+    # Even if names_only is set, html files needs to be opened, because it
+    # can link to images that need to be added to the file set.
+    if names_only and not filepath.endswith('.html'):
+      return ""
+
+    return pattern % ReadFile(filepath)
+
+  def InlineIncludeFiles(src_match):
+    """Helper function to inline external script files"""
+    return InlineFileContents(src_match, '%s')
+
+  def InlineScript(src_match):
+    """Helper function to inline external script files"""
+    return InlineFileContents(src_match, '<script>%s</script>')
+
+  def InlineCSSText(text, css_filepath):
+    """Helper function that inlines external resources in CSS text"""
+    filepath = os.path.dirname(css_filepath)
+    return InlineCSSImages(text, filepath)
+
+  def InlineCSSFile(src_match, inlined_files=inlined_files):
+    """Helper function to inline external css files.
+
+    Args:
+      src_match: A regular expression match with a named group named "filename".
+
+    Returns:
+      The text that should replace the reference to the CSS file.
+    """
+    filepath = GetFilepath(src_match)
+    if filepath is None:
+      return src_match.group(0)
+
+    # Even if names_only is set, the CSS file needs to be opened, because it
+    # can link to images that need to be added to the file set.
+    inlined_files.add(filepath)
+    # When resolving CSS files we need to pass in the path so that relative URLs
+    # can be resolved.
+    return '<style>%s</style>' % InlineCSSText(ReadFile(filepath), filepath)
+
+  def InlineCSSImages(text, filepath=input_filepath):
+    """Helper function that inlines external images in CSS backgrounds."""
+    # Replace contents of url() for css attributes: content, background,
+    # or *-image.
+    return re.sub('(?:content|background|[\w-]*-image):[ ]*' +
+                  'url\((?:\'|\")(?P<filename>[^"\'\)\(]*)(?:\'|\")',
+                  lambda m: SrcReplace(m, filepath),
+                  text)
+
+  flat_text = ReadFile(input_filename)
+
+  if not allow_external_script:
+    # We need to inline css and js before we inline images so that image
+    # references gets inlined in the css and js
+    flat_text = re.sub('<script .*?src="(?P<filename>[^"\']*)".*?></script>',
+                       InlineScript,
+                       flat_text)
+
+  flat_text = re.sub(
+      '<link rel="stylesheet".+?href="(?P<filename>[^"]*)".*?>',
+      InlineCSSFile,
+      flat_text)
+
+  flat_text = re.sub(
+      '<include\s+src="(?P<filename>[^"\']*)".*>',
+      InlineIncludeFiles,
+      flat_text)
+
+  # Check conditional elements, remove unsatisfied ones from the file.
+  flat_text = CheckConditionalElements(flat_text)
+
+  flat_text = re.sub('<(?!script)[^>]+?src="(?P<filename>[^"\']*)"',
+                     SrcReplace,
+                     flat_text)
+
+  # TODO(arv): Only do this inside <style> tags.
+  flat_text = InlineCSSImages(flat_text)
+
+  flat_text = re.sub('<link rel="icon".+?href="(?P<filename>[^"\']*)"',
+                     SrcReplace,
+                     flat_text)
+
+  if names_only:
+    flat_text = None  # Will contains garbage if the flag is set anyway.
+  return InlinedData(flat_text, inlined_files)
+
+
+def InlineToString(input_filename, grd_node, allow_external_script=False):
+  """Inlines the resources in a specified file and returns it as a string.
+
+  Args:
+    input_filename: name of file to read in
+    grd_node: html node from the grd file for this include tag
+  Returns:
+    the inlined data as a string
+  """
+  try:
+    return DoInline(input_filename,
+                    grd_node,
+                    allow_external_script=allow_external_script).inlined_data
+  except IOError, e:
+    raise Exception("Failed to open %s while trying to flatten %s. (%s)" %
+                    (e.filename, input_filename, e.strerror))
+
+
+def InlineToFile(input_filename, output_filename, grd_node):
+  """Inlines the resources in a specified file and writes it.
+
+  Reads input_filename, finds all the src attributes and attempts to
+  inline the files they are referring to, then writes the result
+  to output_filename.
+
+  Args:
+    input_filename: name of file to read in
+    output_filename: name of file to be written to
+    grd_node: html node from the grd file for this include tag
+  Returns:
+    a set of filenames of all the inlined files
+  """
+  inlined_data = InlineToString(input_filename, grd_node)
+  out_file = open(output_filename, 'wb')
+  out_file.writelines(inlined_data)
+  out_file.close()
+
+
+def GetResourceFilenames(filename):
+  """For a grd file, returns a set of all the files that would be inline."""
+  try:
+    return DoInline(filename, None, names_only=True).inlined_files
+  except IOError, e:
+    raise Exception("Failed to open %s while trying to flatten %s. (%s)" %
+                    (e.filename, filename, e.strerror))
+
+
+def main():
+  if len(sys.argv) <= 2:
+    print "Flattens a HTML file by inlining its external resources.\n"
+    print "html_inline.py inputfile outputfile"
+  else:
+    InlineToFile(sys.argv[1], sys.argv[2], None)
+
+if __name__ == '__main__':
+  main()