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_class(class_string):
  13     """
  14     Convert a string version of a function name to the callable object.
  15     """
  16
  17     if not hasattr(class_string, '__bases__'):
  18
  19         try:
  20             class_string = class_string.encode('ascii')
  21             mod_name, class_name = get_mod_func(class_string)
  22             if class_name != '':
  23                 class_string = getattr(__import__(mod_name, {}, {}, ['']), class_name)
  24         except (ImportError, AttributeError):
  25             raise Exception('Failed to import filter %s' % class_string)
  26
  27     return class_string
  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, verbosity=0):
  42     """
  43     Scan the source files for changes and returns True if the output_file needs to be updated.
  44     """
  45
  46     version = get_version(source_files)
  47
  48     on = get_output_filename(output_file, version)
  49     compressed_file_full = media_root(on)
  50
  51     if not os.path.exists(compressed_file_full):
  52         return True, version
  53
  54     update_needed = getattr(get_class(settings.COMPRESS_VERSIONING)(), 'needs_update')(output_file, source_files, version)
  55     return update_needed
  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, prefix=None):
  64     if prefix:
  65         return prefix + urlquote(url)
  66     return django_settings.STATIC_URL + urlquote(url)
  67
  68 def concat(filenames, separator=''):
  69     """
  70     Concatenate the files from the list of the ``filenames``, ouput separated with ``separator``.
  71     """
  72     r = ''
  73     for filename in filenames:
  74         fd = open(media_root(filename), 'rb')
  75         r += fd.read()
  76         r += separator
  77         fd.close()
  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     dirname = os.path.dirname(media_root(filename))
  85     if not os.path.exists(dirname):
  86         os.makedirs(dirname)
  87     fd = open(media_root(filename), 'wb+')
  88     fd.write(contents)
  89     fd.close()
  90
  91 def get_output_filename(filename, version):
  92     if settings.COMPRESS_VERSION and version is not None:
  93         return filename.replace(settings.COMPRESS_VERSION_PLACEHOLDER, version)
  94     else:
  95         return filename.replace(settings.COMPRESS_VERSION_PLACEHOLDER, settings.COMPRESS_VERSION_DEFAULT)
  96
  97 def get_version(source_files, verbosity=0):
  98     version = getattr(get_class(settings.COMPRESS_VERSIONING)(), 'get_version')(source_files)
  99     return version
 100
 101 def get_version_from_file(path, filename):
 102     regex = re.compile(r'^%s$' % (get_output_filename(settings.COMPRESS_VERSION_PLACEHOLDER.join([re.escape(part) for part in filename.split(settings.COMPRESS_VERSION_PLACEHOLDER)]), r'([A-Za-z0-9]+)')))
 103     for f in os.listdir(path):
 104         result = regex.match(f)
 105         if result and result.groups():
 106             return result.groups()[0]
 107
 108 def remove_files(path, filename, verbosity=0):
 109     regex = re.compile(r'^%s$' % (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]+'))))
 110     if os.path.exists(path):
 111         for f in os.listdir(path):
 112             if regex.match(f):
 113                 if verbosity >= 1:
 114                     print "Removing outdated file %s" % f
 115
 116                 os.unlink(os.path.join(path, f))
 117
 118 def filter_common(obj, verbosity, filters, attr, separator, signal):
 119     output = concat(obj['source_filenames'], separator)
 120
 121     filename = get_output_filename(obj['output_filename'], get_version(obj['source_filenames']))
 122
 123     if settings.COMPRESS_VERSION:
 124         remove_files(os.path.dirname(media_root(filename)), obj['output_filename'], verbosity)
 125
 126     if verbosity >= 1:
 127         print "Saving %s" % filename
 128
 129     for f in filters:
 130         output = getattr(get_class(f)(verbose=(verbosity >= 2)), attr)(output)
 131
 132     save_file(filename, output)
 133     signal.send(None)
 134
 135 def filter_css(css, verbosity=0):
 136     return filter_common(css, verbosity, filters=settings.COMPRESS_CSS_FILTERS, attr='filter_css', separator='', signal=css_filtered)
 137
 138 def filter_js(js, verbosity=0):
 139     return filter_common(js, verbosity, filters=settings.COMPRESS_JS_FILTERS, attr='filter_js', separator='', signal=js_filtered)