This Django app adds a new field type, ValidatedFileField, that add the capability of checking the document size and types the user may send.
NOTE: there is a fork of this utility, at https://github.com/mbourqui/django-constrainedfilefield, that is more maintained and updated, and adds some nice features like a javascript validator. We recommend using ConstrainedFileField instead of ValidatedFile.
- Download and install package with python setup.py install.
- Note that this package depends on python-magic (to check field types).
- For windows, you must download the dll files and .magic file at https://github.com/pidydx/libmagicwin64 (32-bit version: http://gnuwin32.sourceforge.net/packages/file.htm)), add them to C:\Windows\System32 (or to a folder in your PATH), and set MAGIC_FILE_PATH="..." to the path of your .magic file in your settings.py. For more information about the files to download, go to: https://github.com/ahupp/python-magic/blob/43df08c5ed63d7aad839695f311ca1be2eeb1ecb/README.md#dependencies
- Add 'validatedfile' to your INSTALLED_APPS in settings.py.
Create a model and add a field of type ValidatedFileField. You can add a maximum size in bytes and a list of valid mime types that will be allowed. The list of all mime types is available here: http://www.iana.org/assignments/media-types/index.html:
from django.db import models
from validatedfile.fields import ValidatedFileField
class TestModel(models.Model):
the_file = ValidatedFileField(
null = True,
blank = True,
upload_to = 'testfile',
max_upload_size = 10240,
content_types = ['image/png'])
The model can be used in forms or model forms like a normal FileField. If a user tries to upload a file with too much size or without a valid type, a form validation error will occur.
This example also checks the total size of all files uploaded by one user:
(in models.py)
from django.contrib.auth.models import User
from django.db import models
from validatedfile.fields import ValidatedFileField
class TestModel(models.Model):
user = models.ForeignKey(
User,
null = False,
blank = False,
related_name = 'test_models')
the_file = ValidatedFileField(
null = True,
blank = True,
upload_to = 'testfile',
max_upload_size = 10240,
content_types = ['image/png'])
(in forms.py)
from django import forms
from validatedfile.fields import QuotaValidator
from models.py import TestModel
class TestModelForm(models.ModelForm):
the_file = forms.FileField(
required = True,
validators = [QuotaValidator(max_usage = 102400)])
class Meta:
model = TestModel
fields = ['the_file']
def __init__(self, user, *args, **kwargs):
super(TestModelForm, self).__init__(*args, **kwargs)
self.user = user
self.fields['the_file'].validators[0].update_quota(
items = self.user.test_models.all(),
attr_name = 'the_file',
)
def exceeds_quota(self):
return self.fields['the_file'].validators[0].quota.exceeds()
def save(self, *args, **kwargs):
model = super(TestModelForm, self).save(commit = False)
model.user = self.user
model.save()
Important note: the check of the file size is made by Django once the whole file has been uploaded to the server and stored in a temp directory (or in memory if the file is small). Thus, this is useful to guarantee the quota of the users, for example, but will not stop an attacking user that wants to block the server by sending huge files (e. g. of several Gb).
To avoid this, you need to configure your front end to limit the size of uploaded files. How to do it depends on the software you are using. For example, if you use apache, you should use LimitRequestBody directive (http://httpd.apache.org/docs/2.2/mod/core.html#limitrequestbody).
This is a complementary measure, because you'll usually want normal users that exceed the size by a reasonable amount to get a friendly form validation message, while attacking users will see how their connection is abruptly cut before the file finishes uploading. So the recommended setting is to give max_upload_size a small value (e.g. 5Mb) and LimitRequestBody a higher one (e.g. 100Mb).