Base64 rest file/image fields

# shared/models/utils.py
import base64
import mimetypes
import re
import six
import uuid

from django.core.files.base import ContentFile
from django.utils.functional import LazyObject


class Base64ImageConverter:

    @staticmethod
    def decode_file(data):
        if isinstance(data, six.string_types):
            _data = re.sub(r"^data\:.+base64\,(.+)$", r"\1", data)
            try:
                return base64.b64decode(_data)
            except Exception as exception:
                pass
        return

    def convert(self, data):
        file_name, delim, content = str(data).partition(';')
        decoded_data = self.decode_file(content)
        if not decoded_data:
            return
        return ContentFile(decoded_data, name=file_name)


class DefaultBase64ImageConverter(LazyObject):
    def _setup(self):
        self._wrapped = Base64ImageConverter()


default_base64_file_converter = DefaultBase64ImageConverter()


# shared/rest/fields.py
from django.utils.translation import ugettext_lazy as _

from rest_framework.serializers import FileField, ImageField

from ..models.utils import default_base64_file_converter


class Base64FileFieldMixin:
    message = None

    def __init__(self, message=None, **kwargs):
        super().__init__(**kwargs)
        if message:
            self.message = message

    def to_internal_value(self, data):
        try:
            data = default_base64_file_converter.convert(data)
        except Exception as ex:
            self.fail(self.message)
        return super().to_internal_value(data)


class Base64FileSerializerField(Base64FileFieldMixin, FileField):
    message = _("Invalid file was passed")


class Base64ImageSerializerField(Base64FileFieldMixin, ImageField):
    message = _("Invalid image was passed")