apps/compress/utils.py

   1 import os
   2 import re
   3 import tempfile
   4
   5 from django.conf import settings as django_settings
   6 from django.utils.http import urlquote
   7 from django.dispatch import dispatcher
   8
   9 from compress.conf import settings
  10 from compress.signals import css_filtered, js_filtered
  11
  12 def get_filter(compressor_class):
  13     """
  14     Convert a string version of a function name to the callable object.
  15     """
  16
  17     if not hasattr(compressor_class, '__bases__'):
  18
  19         try:
  20             compressor_class = compressor_class.encode('ascii')
  21             mod_name, class_name = get_mod_func(compressor_class)
  22             if class_name != '':
  23                 compressor_class = getattr(__import__(mod_name, {}, {}, ['']), class_name)
  24         except (ImportError, AttributeError):
  25             raise Exception('Failed to import filter %s' % compressor_class)
  26
  27     return compressor_class
  28
  29 def get_mod_func(callback):
  30     """
  31     Converts 'django.views.news.stories.story_detail' to
  32     ('django.views.news.stories', 'story_detail')
  33     """
  34
  35     try:
  36         dot = callback.rindex('.')
  37     except ValueError:
  38         return callback, ''
  39     return callback[:dot], callback[dot+1:]
  40
  41 def needs_update(output_file, source_files):
  42     """
  43     Scan the source files for changes and returns True if the output_file needs to be updated.
  44     """
  45
  46     mtime = max_mtime(source_files)
  47     version = get_version(mtime)
  48
  49     compressed_file_full = media_root(get_output_filename(output_file, version))
  50
  51     if not os.path.exists(compressed_file_full):
  52         return True, version
  53
  54     # Check if the output file is outdated
  55     return (os.stat(compressed_file_full).st_mtime < mtime), mtime
  56
  57 def media_root(filename):
  58     """
  59     Return the full path to ``filename``. ``filename`` is a relative path name in MEDIA_ROOT
  60     """
  61     return os.path.join(django_settings.STATIC_ROOT, filename)
  62
  63 def media_url(url):
  64     return django_settings.STATIC_URL + urlquote(url)
  65
  66 def concat(filenames, separator=''):
  67     """
  68     Concatenate the files from the list of the ``filenames``, ouput separated with ``separator``.
  69     """
  70     r = ''
  71
  72     for filename in filenames:
  73         fd = open(media_root(filename), 'rb')
  74         r += fd.read()
  75         r += separator
  76         fd.close()
  77
  78     return r
  79
  80 def max_mtime(files):
  81     return int(max([os.stat(media_root(f)).st_mtime for f in files]))
  82
  83 def save_file(filename, contents):
  84     fd = open(media_root(filename), 'wb+')
  85     fd.write(contents)
  86     fd.close()
  87
  88 def get_output_filename(filename, version):
  89     if settings.COMPRESS_VERSION and version is not None:
  90         return filename.replace(settings.COMPRESS_VERSION_PLACEHOLDER, get_version(version))
  91     else:
  92         return filename.replace(settings.COMPRESS_VERSION_PLACEHOLDER, settings.COMPRESS_VERSION_DEFAULT)
  93
  94 def get_version(version):
  95     try:
  96         return str(int(version))
  97     except ValueError:
  98         return str(version)
  99
 100 def remove_files(path, filename, verbosity=0):
 101     regex = re.compile(r'^%s$' % (os.path.basename(get_output_filename(settings.COMPRESS_VERSION_PLACEHOLDER.join([re.escape(part) for part in filename.split(settings.COMPRESS_VERSION_PLACEHOLDER)]), r'\d+'))))
 102
 103     for f in os.listdir(path):
 104         if regex.match(f):
 105             if verbosity >= 1:
 106                 print "Removing outdated file %s" % f
 107
 108             os.unlink(os.path.join(path, f))
 109
 110 def filter_common(obj, verbosity, filters, attr, separator, signal):
 111     output = concat(obj['source_filenames'], separator)
 112     filename = get_output_filename(obj['output_filename'], get_version(max_mtime(obj['source_filenames'])))
 113
 114     if settings.COMPRESS_VERSION:
 115         remove_files(os.path.dirname(media_root(filename)), obj['output_filename'], verbosity)
 116
 117     if verbosity >= 1:
 118         print "Saving %s" % filename
 119
 120     for f in filters:
 121         output = getattr(get_filter(f)(verbose=(verbosity >= 2)), attr)(output)
 122
 123     save_file(filename, output)
 124     signal.send(None)
 125
 126 def filter_css(css, verbosity=0):
 127     return filter_common(css, verbosity, filters=settings.COMPRESS_CSS_FILTERS, attr='filter_css', separator='', signal=css_filtered)
 128
 129 def filter_js(js, verbosity=0):
 130     return filter_common(js, verbosity, filters=settings.COMPRESS_JS_FILTERS, attr='filter_js', separator=';', signal=js_filtered)