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
  13 def get_class(class_string):
  14     """
  15     Convert a string version of a function name to the callable object.
  16     """
  17
  18     if not hasattr(class_string, '__bases__'):
  19
  20         try:
  21             class_string = class_string.encode('ascii')
  22             mod_name, class_name = get_mod_func(class_string)
  23             if class_name != '':
  24                 class_string = getattr(__import__(mod_name, {}, {}, ['']), class_name)
  25         except (ImportError, AttributeError):
  26             raise Exception('Failed to import filter %s' % class_string)
  27
  28     return class_string
  29
  30
  31 def get_mod_func(callback):
  32     """
  33     Converts 'django.views.news.stories.story_detail' to
  34     ('django.views.news.stories', 'story_detail')
  35     """
  36
  37     try:
  38         dot = callback.rindex('.')
  39     except ValueError:
  40         return callback, ''
  41     return callback[:dot], callback[dot + 1:]
  42
  43
  44 def needs_update(output_file, source_files, verbosity=0):
  45     """
  46     Scan the source files for changes and returns True if the output_file needs to be updated.
  47     """
  48
  49     version = get_version(source_files)
  50
  51     on = get_output_filename(output_file, version)
  52     compressed_file_full = media_root(on)
  53
  54     if not os.path.exists(compressed_file_full):
  55         return True, version
  56
  57     update_needed = getattr(get_class(settings.COMPRESS_VERSIONING)(), 'needs_update')(output_file, source_files, version)
  58     return update_needed
  59
  60
  61 def media_root(filename):
  62     """
  63     Return the full path to ``filename``. ``filename`` is a relative path name in MEDIA_ROOT
  64     """
  65     return os.path.join(django_settings.STATIC_ROOT, filename)
  66
  67
  68 def media_url(url, prefix=None):
  69     if prefix:
  70         return prefix + urlquote(url)
  71     return django_settings.STATIC_URL + urlquote(url)
  72
  73
  74 def concat(filenames, separator=''):
  75     """
  76     Concatenate the files from the list of the ``filenames``, ouput separated with ``separator``.
  77     """
  78     r = ''
  79     for filename in filenames:
  80         fd = open(media_root(filename), 'rb')
  81         r += fd.read()
  82         r += separator
  83         fd.close()
  84     return r
  85
  86
  87 def max_mtime(files):
  88     return int(max([os.stat(media_root(f)).st_mtime for f in files]))
  89
  90
  91 def save_file(filename, contents):
  92     dirname = os.path.dirname(media_root(filename))
  93     if not os.path.exists(dirname):
  94         os.makedirs(dirname)
  95     fd = open(media_root(filename), 'wb+')
  96     fd.write(contents)
  97     fd.close()
  98
  99
 100 def get_output_filename(filename, version):
 101     if settings.COMPRESS_VERSION and version is not None:
 102         return filename.replace(settings.COMPRESS_VERSION_PLACEHOLDER, version)
 103     else:
 104         return filename.replace(settings.COMPRESS_VERSION_PLACEHOLDER, settings.COMPRESS_VERSION_DEFAULT)
 105
 106
 107 def get_version(source_files, verbosity=0):
 108     version = getattr(get_class(settings.COMPRESS_VERSIONING)(), 'get_version')(source_files)
 109     return version
 110
 111
 112 def get_version_from_file(path, filename):
 113     regex = re.compile(r'^%s$' % (get_output_filename(settings.COMPRESS_VERSION_PLACEHOLDER.join([re.escape(part) for part in filename.split(settings.COMPRESS_VERSION_PLACEHOLDER)]), r'([A-Za-z0-9]+)')))
 114     for f in os.listdir(path):
 115         result = regex.match(f)
 116         if result and result.groups():
 117             return result.groups()[0]
 118
 119
 120 def remove_files(path, filename, verbosity=0):
 121     regex = re.compile(r'^%s$' % (os.path.basename(get_output_filename(settings.COMPRESS_VERSION_PLACEHOLDER.join([re.escape(part) for part in filename.split(settings.COMPRESS_VERSION_PLACEHOLDER)]), r'[A-Za-z0-9]+'))))
 122     if os.path.exists(path):
 123         for f in os.listdir(path):
 124             if regex.match(f):
 125                 if verbosity >= 1:
 126                     print "Removing outdated file %s" % f
 127
 128                 os.unlink(os.path.join(path, f))
 129
 130
 131 def filter_common(obj, verbosity, filters, attr, separator, signal):
 132     output = concat(obj['source_filenames'], separator)
 133
 134     filename = get_output_filename(obj['output_filename'], get_version(obj['source_filenames']))
 135
 136     if settings.COMPRESS_VERSION:
 137         remove_files(os.path.dirname(media_root(filename)), obj['output_filename'], verbosity)
 138
 139     if verbosity >= 1:
 140         print "Saving %s" % filename
 141
 142     for f in filters:
 143         output = getattr(get_class(f)(verbose=(verbosity >= 2)), attr)(output)
 144
 145     save_file(filename, output)
 146     signal.send(None)
 147
 148
 149 def filter_css(css, verbosity=0):
 150     return filter_common(css, verbosity, filters=settings.COMPRESS_CSS_FILTERS, attr='filter_css', separator='', signal=css_filtered)
 151
 152
 153 def filter_js(js, verbosity=0):
 154     return filter_common(js, verbosity, filters=settings.COMPRESS_JS_FILTERS, attr='filter_js', separator='', signal=js_filtered)