Access pre-update records UpdateView

I am trying to pass two dates to a javascript datepicker so that the picker can display the current dates held in the record that is about to be updated using UpdateView.

I understand that simply passing the variables via a template tag of, say: {{ form.check_in.value }} is vulnerable to XSS, so I want to do this in a secure way.

The best way seems to be via def get_context_data() where I have the following code:

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context['guest'] = GuestLead.objects.get(
        context['dates'] = json.dumps({'check_in': '2022-09-01', 'check_out': '2022-09-10'})

and then the template tag would look like:
{{ dates|json_script:“check_in” }}
Which renders as this:

<script id="check_in" type="application/json">"{\"check_in\": \"2022-09-01\", \"check_out\": \"2022-09-10\"}"</script>

What I need to know is how I can access the date records so that I can make the get_context_data, context[‘dates’] = json.dumps({‘check_in’: ‘2022-09-01’, ‘check_out’: ‘2022-09-10’}) reflect the database record values before they are updated.

I would rather not make another wasteful query as the data must be available in the self.object.

Maybe I’m on the wrong track?

I don’t understand the issue here.

If the data is available in self.object, what’s the problem?

Thanks Ken.

Yes, it works now.
I could have sworn that I tried self.object.check_in, even now PyCharm is not giving .check_in as an available option to self.object.

Thanks again.