validating file contents when uploading to Django form

Vote count:

0

I am trying to validate a CSV file uploaded into Django Admin - to make sure it's in the right format and so on.

It also relies on another value in the form so I am validating it inside the forms clean method:

def clean(self):
    cleaned_data = super(CSVInlineForm, self).clean()
    csv_file = cleaned_data.get('csv_file')
    contents = csv_file.read()
    # ...validate contents here...
    return cleaned_data

My model save method looks like this:

def save(self, *args, **kwargs):
    contents = self.csv_file.read()
    # ... do something with the contents here ...
    return super(CSVModel, self).save(*args, **kwargs)

The problem comes when I read the file contents inside the clean method, I can not read the csv_file inside the model save method (it returns an empty string). Inside the clean method I can read and parse the file.

The file is uploaded perfectly fine and intact.

If I comment out the csv_file.read() line in the clean method, the save method works fine and can read the file contents.

It's behaving as if the file can only be read once?

And if I re-save the model the file reading and parsing works normally.

This is all within django admin - the forms are being handled correctly as far as I can tell.

asked 1 min ago

Guy Bowden

952