Allow SVG files to be uploaded to ImageField via Django admin

Question

I'm switching to SVG images to represent categories on my e-commerce platform. I was using models.ImageField in the Category model to store the images before, but the forms.ImageField validation is not capable of handling a vector-based image (and therefore rejects it).

I don't require thorough validation against harmful files, since all uploads will be done via the Django Admin. It looks like I'll have to switch to a models.FileField in my model, but I do want warnings against uploading invalid images.

Nick Khlestov wrote a SVGAndImageFormField (find source within the article, I don't have enough reputation to post more links) over django-rest-framework's ImageField. How do I use this solution over Django's ImageField (and not the DRF one)?

Answer 1

I have never used SVGAndImageFormField so I cannot really comment on that. Personally I would have opted for a simple application of FileField, but that clearly depends on the project requirements. I will expand on that below:

As mentioned in the comment, the basic difference between an ImageField and a FileField is that the first checks if a file is an image using Pillow:

Inherits all attributes and methods from FileField, but also validates that the uploaded object is a valid image.

Reference: Django docs, Django source code

It also offers a couple of attributes possibly irrelevant to the SVG case (height, width).

Therefore, the model field could be:

    svg = models.FileField(upload_to=..., validators=[validate_svg])

You can use a function like is_svg as provided in the relevant question:

How can I say a file is SVG without using a magic number?

Then a function to validate SVG:

def validate_svg(file, valid):
    if not is_svg(file):
        raise ValidationError("File not svg")