using File storage
Jiri Barton
models?
class Chart(models.Model):
xml = models.FileField(upload_to='charts')
...
I would like compute the image on the fly, using some data in the
database. How should I store the generated data? How should I use File
storage for this task?
I would like Django to take care of the file naming for me. I would
like to use a one-liner such as
Chart.objects.create(xml=default_storage.save('data.xml', data))
where data is a string, but that gives me
AttributeError: 'str' object has no attribute 'chunks'
The example from http://www.djangoproject.com/documentation/files/#storage-objects
does not work for me either:
>>> from django.core.files.storage import default_storage
>>> path = default_storage.save('/path/to/file', 'new content')
This will give me
<type 'exceptions.AttributeError'>: 'str' object has no attribute
'chunks'
Should I use the class File directly? How? For File.save() to work, I
would need an associated an object. Please advise.
Thank you
Tim Kersten
have a file like object from a string, and use that to make your
django File object (
http://www.djangoproject.com/documentation/files/#the-file-object ).
There's probably a better way than this though so you might want to
wait for other replies.
import StringIO
from django.core.files import File
f = StringIO.StringIO()
f.write(data)
myfile = File(f)
Chart.objects.create(xml=default_storage.save('data.xml', myfile))
Tim ^,^
Marty Alchin
> I would like Django to take care of the file naming for me. I would
> like to use a one-liner such as
>
> Chart.objects.create(xml=default_storage.save('data.xml', data))
You're nearly there for getting this to work, it's just the matter of
how you're passing in the data. Try importing ContentFile from
django.core.files.base, and using it like so:
Chart.objects.create(xml=default_storage.save('data.xml', ContentFile(data)))
> The example from http://www.djangoproject.com/documentation/files/#storage-objects
> does not work for me either:
>
>>>> from django.core.files.storage import default_storage
>
>>>> path = default_storage.save('/path/to/file', 'new content')
>
> This will give me
>
> <type 'exceptions.AttributeError'>: 'str' object has no attribute
> 'chunks'
Egad! Would you mind opening a ticket for this? That example is
definitely wrong, and will need to be updated.
-Gul
Tim Kersten
ha, I was almost certain that django wouldn't make it as hard as I had
explained it. :-D Glad to see it's this easy!
Tim ^,^
julianb
> There's probably a better way than this though so you might want to
> wait for other replies.
>
> import StringIO
> from django.core.files import File
> f = StringIO.StringIO()
> f.write(data)
> myfile = File(f)
> Chart.objects.create(xml=default_storage.save('data.xml', myfile))
no attribute 'name'...
Tim Kersten
write code without testing it yourself... something is often missed
:-)
This should fix the error you got:
import StringIO
from django.core.files import File
f = StringIO.StringIO()
f.name, f.mode = 'data.xml', 'r'
f.write(data)
myfile = File(f)
Chart.objects.create(xml=default_storage.save(f.name, myfile))
However, Marty's solution seems a lot nicer. Did that not work? I've
never done anything like what I've shown you - it was more or less a
straight guess as to how it might work. Marty's solution looks a lot
more correct and a lot cleaner too. Perhaps you should be trying to
make that work instead?
Tim ^,^
julianb
> This should fix the error you got:
>
> import StringIO
> from django.core.files import File
> f = StringIO.StringIO()
> f.name, f.mode = 'data.xml', 'r'
> f.write(data)
> myfile = File(f)
> Chart.objects.create(xml=default_storage.save(f.name, myfile))
>
> However, Marty's solution seems a lot nicer. Did that not work? I've
> never done anything like what I've shown you - it was more or less a
> straight guess as to how it might work. Marty's solution looks a lot
> more correct and a lot cleaner too. Perhaps you should be trying to
> make that work instead?
did not throw errors, but the file I got was 0 bytes. I will try again
and check if I made a mistake or so...
julianb
> I tried several things, I think Marty's solution was among them. It
> did not throw errors, but the file I got was 0 bytes. I will try again
> and check if I made a mistake or so...
big = StringIO.StringIO() # you have a StringIO
...
image.save(big, "JPEG", quality=70) # write something to the StringIO
...
# Photo is a model that has an image field
photo = Photo(user=creator)
# use getvalue because ContentFile just needs content
big_file = ContentFile(big.getvalue())
# use save method of image field, no other function!
photo.data.save("%s.jpg" % name, big_file)