Creating temperory files for a web application

[Diez B. Roggisch]

koranthala wrote:

> Hi,
>    I am doing web development using Django. I need to create an image
> (chart) and show it to the users - based on some data which user
> selects.
>    My question is - how do I create a temporary image for the user? I
> thought of tempfile, but I think it will be deleted once the process
> is done - which would happen by the time user starts seeing the image.

What makes you think that? You are the one creating it, you are responsible
for deleting it.

> I can think of no other option other than to have another script which
> will delete all images based on time of creation.
>    Since python is extensively used for web development, I guess this
> should be an usual scenario for many people here. How do you usually
> handle this?

There are various solutions - tempfiles, files based on a criteria (e.g.
username and image-properties) so that they don't pollute the harddrive.

For both approaches cleaning up as you suggest might be needed.

Alternatively, if you use sessions, you can use memory-cached images.

Or you can use the database.

But the cleaning-up might get necessary here as well.

The cleanest solution would be if the image would be rendered on the fly,
based on GET-parameters (or REST-ful urls) so that you can render it into
memory as string, but then forget immediately about it.

Diez