'Canvas' object has no attribute '_committed'-CodePudding

I'm trying to save the canvas object to my django model field file but it says "'Canvas' object has no attribute '_committed'".

p.setTitle(f"{patient.first_name} {patient.last_name}'s Report")
p.showPage()
p.save()

pdf:bytes =buffer.getvalue()
buffer.close()
response.write(pdf)    

r = Result.objects.filter(score="12").update_or_create(file=p)

Can anyone help me out with this issue?

CodePudding user response：

"You must pass an instance of django's File object to FileField.save() to change the content of a file field. It works a bit differently from other types of model fields." Quoted from here

CodePudding user response：

You can not use an .update_or_create(…) [Django-doc] after a .filter(…) [Django-doc]. What you probably wanted is to use:

Result.objects.update_or_create(
    score='12',
    defaults={'file': p}
)

This will however not work with p: p is not a file, it is a Canvas object. You can use the file name, or work with a FieldFile object [Django-doc].

CodePudding user response：

Well instead of using

buffer =BytesIO()
buffer.close()

I used

buffer.seek(0)
r = Result.objects.get(pk=result_id)    
r.file.save(f"{d}.pdf", File(buffer))

and it worked.