def check_word_or_excel(self, fileobj, detected_type, extension):
"""
Returns proper mimetype in case of word or excel files
"""
word_strings = [
'Microsoft Word', 'Microsoft Office Word',
'Microsoft Macintosh Word'
]
excel_strings = [
'Microsoft Excel', 'Microsoft Office Excel',
'Microsoft Macintosh Excel'
]
office_strings = ['Microsoft OOXML']
file_type_details = magic.from_buffer(fileobj.read(READ_SIZE))
fileobj.seek(0)
if any(string in file_type_details for string in word_strings):
detected_type = 'application/msword'
elif any(string in file_type_details for string in excel_strings):
detected_type = 'application/vnd.ms-excel'
elif any(string in file_type_details for string in office_strings) or \
(detected_type == 'application/vnd.ms-office'):
if extension in ('.doc', '.docx'):
detected_type = 'application/msword'
if extension in ('.xls', '.xlsx'):
detected_type = 'application/vnd.ms-excel'
return detected_type
def __call__(self, fileobj):
detected_type = magic.from_buffer(fileobj.read(READ_SIZE), mime=True)
root, extension = os.path.splitext(fileobj.name.lower())
# seek back to start so a valid file could be read
# later without resetting the position
fileobj.seek(0)
# some versions of libmagic do not report proper mimes for Office subtypes
# use detection details to transform it to proper mime
if detected_type in ('application/octet-stream',
'application/vnd.ms-office'):
detected_type = self.check_word_or_excel(fileobj, detected_type,
extension)
if detected_type not in self.allowed_mimes:
# use more readable file type names for feedback message
allowed_types = map(lambda mime_type: mime_type.split('/')[1],
self.allowed_mimes)
raise ValidationError(message=self.type_message,
params={
'detected_type': detected_type,
'allowed_types': ', '.join(allowed_types)
},
code='invalid_type')
if self.allowed_exts and (extension not in self.allowed_exts):
raise ValidationError(message=self.extension_message,
params={
'extension':
extension,
'allowed_extensions':
', '.join(self.allowed_exts)
},
code='invalid_extension')