Django: Generating a file on page load and deleting it upon exit

Something I would like to do in my Django app is: every time a user views page A, grab information from my database, generate an image based off this and display it to the user. Since I am regenerating an image each time I view the page, I would like it to be unique to each user and deleted when they leave page A to go to any arbitrary page B (and ideally when they simply click x on the browser too, but if not that's okay).

So far I can generate the image file and save it just fine. I have tried a few things unsuccessfully and can't figure out how to go forward.

Things I have tried:

1. @receiver(request_finished)

@receiver(request_finished)
def handle_request_finished(sender, **kwargs):
    ... clean up files here ...

My issue with this one is that it happens too quickly and won't load the picture on page A because it will be deleted already.

2. Using a JavaScript function that activates when leaving the page paired with a function in my views.py

In template.html:

<script>
  $(window).on('beforeunload', function () {
    $.ajax({
      url: pageLeaveUrl,  // links to page_leave function in views.py
      type: 'GET',
      async: false  // Ensure the request completes before page unloads
    });
  });
</script>

In views.py:

def page_leave(request):
    referer = request.META.get('HTTP_REFERER')
    
    ... clean up files ...

    if referer:
        return redirect(referer)
    else:
        return redirect('home')

My issue with this one is that referer always redirects to page A first and then page B (where they are trying to go) which means I succesfully deleted the generated image, but then another is generated in its place.

3. I also toyed around with import django.http.FileResponse but couldn't get anything working.

Thanks in advance for any help.

EDIT:

I made progress doing the following.
By adding the following check in my views.py in addition to approach 2:

def get(self, request):
    ... initialize stuff ...

    if str(request.META.get('HTTP_REFERER')).__contains__("page_A"):
        ... clean up files ...
    else:
        ... normal actions upon viewing page A ...

this almost works because there is another request when leaving the page. This checks if the page that you are leaving is page A, and if it is then clean up happens. I also checked and this works for both refreshing and exiting the browser. However, it doesn't work if I click a button on my sidebar to take me to page A from page A. It detects that I'm leaving page A but because of the way I set it up, doesn't detect that I'm coming back.

This is not the direct answer to OP's question "how to store and delete files", but is a in my opinion even preferable alternative. Using a temporary buffer never "really" stores the file on disk. So after the view function ran, the buffer is simply dropped and gone.

Since OP said in the comments that he is using matplotlib this piece of matplotlib documentation will bring you on track.

Remember: You want to utilize fig.Figure. The use of matplotlib.pyplot results in memory leaks. Don't worry, there is almost no difference.

import base64
from io import BytesIO
from matplotlib.figure import Figure

def give_plot():
    # Generate the figure **without using pyplot**.
    fig = Figure()
    ax = fig.subplots()
    ax.plot([1, 2]) # <-- replace this line for your plotting logic
    # Save it to a temporary buffer.
    buf = BytesIO()
    fig.savefig(buf, format="png")
    # Embed the result in the html output.
    data = base64.b64encode(buf.getbuffer()).decode("ascii")
    return f"<img src='data:image/png;base64,{data}'/>"

# views.py
def yourview(request):
    # [...]
    context = {}
    context["plot_div"] = give_plot()  # here you could pass data to the fuction
    return render(request, 'app/my_template.html', context=context)

<!--my_template.html-->
{% autoescape off %}
  {{ plot_div }}
{% endautoescape %}