[Django]-Maximum recursion depth exceeded, save method, Django

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7👍

✅

self.qrcode.save means that the whole model object needs to be saved, so it leads to a call to save which calls generate_qrcode which calls self.qrcode.save… (by the way you should be able to see this in the traceback) so your problem has nothing to do with BytesIO. Insert a condition somewhere to break the recursive loop.

👤Alex Hall

2👍

okey here is my full solution for models.Model who works with slug field and also get_absolute_url and qr_code

class Posts(models.Model):
    slug = models.SlugField(unique=True)
    title = models.CharField(max_length=30)
    my_qrcode = models.ImageField(upload_to='qrCode', null=True, blank=True)

    def save(self, *args, **kwargs):
        # we override the save method other wise, slug will not be effect and get_absolute_url will not work
        if self.slug:
            pass # here prevents to create slug again when updating your posts
        else:
            self.generate_qrcode()
        super(Posts,self).save(*args, **kwargs)

    def get_absolute_url(self):
        return reverse('posts:detail', kwargs={'slug':self.slug})

    def generate_qrcode(self):
        # this part creates unique slugs
        slug = slugify(self.title)
        while self.__class__.objects.filter(slug=slug).order_by('-id').exists():
            qs = self.__class__.objects.filter(slug=slug).order_by('-id')
            new_slug = '%s-%s' % (slug, qs.first().id)
            slug = new_slug
        self.slug = slug

        qr = qrcode.QRCode(
            version=1,
            error_correction=qrcode.constants.ERROR_CORRECT_L,
            box_size=6,
            border=0,
        )
        qr.add_data(self.get_absolute_url())
        qr.make(fit=True)

        img = qr.make_image()

        buffer = StringIO.StringIO()
        img.save(buffer)
        filename = 'QrCode-%s.png' % (slug)
        filebuffer = InMemoryUploadedFile(buffer, None, filename, 'image/png', buffer.len, None)
        self.my_qrcode.save(filename, filebuffer, False) # we already have save method so just make False itself save behavior

just it, benefit of helping.

👤Ozan Honamlioglu

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