Django: Validate file type of uploaded file
django, django-models, django-uploads
Solution
For posterity: the solution is to use the `read` method and pass that to `magic.from_buffer`.
class UploadedFileForm(ModelForm):
def clean_file(self):
file = self.cleaned_data.get("file", False)
filetype = magic.from_buffer(file.read())
if not "XML" in filetype:
raise ValidationError("File is not XML.")
return file
class Meta:
model = models.UploadedFile
exclude = ('project',)
Problem
I have an app that lets people upload files, represented as `UploadedFiles`. However, I want to make sure that users only upload xml files. I know I can do this using `magic`, but I don't know where to put this check - I can't put it in the `clean` function since the file is not yet uploaded when `clean` runs, as far as I can tell. Here's the `UploadedFile` model: ``` class UploadedFile(models.Model): """This represents a file that has been uploaded to the server.""" STATE_UPLOADED = 0 STATE_ANNOTATED = 1 STATE_PROCESSING = 2 STATE_PROCESSED = 4 STATES = ( (STATE_UPLOADED, "Uploaded"), (STATE_ANNOTATED, "Annotated"), (STATE_PROCESSING, "Processing"), (STATE_PROCESSED, "Processed"), ) status = models.SmallIntegerField(choices=STATES, default=0, blank=True, null=True) file = models.FileField(upload_to=settings.XML_ROOT) project = models.ForeignKey(Project) def __unicode__(self): return self.file.name def name(self): return os.path.basename(self.file.name) def save(self, *args, **kwargs): if not self.status: self.status = self.STATE_UPLOADED super(UploadedFile, self).save(*args, **kwargs) def delete(self, *args, **kwargs): os.remove(self.file.path) self.file.delete(False) super(UploadedFile, self).delete(*args, **kwargs) def get_absolute_url(self): return u'/upload/projects/%d' % self.id def clean(self): if not "XML" in magic.from_file(self.file.url): raise ValidationError(u'Not an xml file.') class UploadedFileForm(forms.ModelForm): class Meta: model = UploadedFile exclude = ('project',) ```