How to associate newly created file model-CodePudding

I have this code,

@receiver(post_save, sender=FileAnswer)
def save_category_signals(sender, instance, **kwargs):    
    file_types =  ["image", "image-multiple"]
    file_type = instance.question.form_input_type
    if file_type in file_types:
        image_path = instance.body.path
        image = Image.open(image_path)
        img = image.convert('RGB')
        new_path = image_path.rsplit('.', 1)
        pdf = img.save(f'{new_path[0]}_{instance.id}.pdf', format="PDF")
        # os.remove(image_path)
        
        instance.body = pdf
        instance.save()
    
    # os.remove(image_path) # remove old image

This code does not associate the file to the model instance. I have looked at django ContentFile and File. still can't really wrap my head around it as the examples aren't that helpful.

CodePudding user response：

try something like this you should use InMemoryUploadedFile:

@receiver(post_save, sender=FileAnswer)
def save_category_signals(sender, instance, **kwargs):    
    file_types =  ["image", "image-multiple"]
    file_type = instance.question.form_input_type
    if file_type in file_types:
        image_path = instance.body.path
        new_path = image_path.rsplit('.', 1)
        image = Image.open(image_path)
        image = image.convert('RGB')
        output = io.BytesIO()
        image.save(output, format='PDF')
        output.seek(0)
        pdf = InMemoryUploadedFile(output, 'FileField',
                                   f'{new_path[0]}_{instance.id}.pdf',
                                    'application/pdf',
                                    sys.getsizeof(output), None)
        # os.remove(image_path)
        
        instance.body = pdf
        instance.save()
    
    # os.remove(image_path) # remove old image