check if internal url is reachable (200 status code)

Using Django Forms & APIs
1

Hi all,

I have a class based view to display some (filtered) objects. In this page I can select checkboxes to delete some records. The delete view gets the source url with parameters from the template and I use this url to redirect to the “source” page after the deletion. In the parameters of the source url there is also the number of the page:

https://mysite.test/path/?firstparameter=1&secondparameter=2&page=2

actually it’s passed without the scheme and the domain, like so:

/path/?firstparameter=1&secondparameter=2&page=2

After the deletion it can happen that the link with the page is not working (http status code 404). It is normal but how can I test in the view before the redirect if the link is working and reachable (http status code 200)?

Thanks in advance,

supermario18b

2

Depending upon exactly how you’ve constructed your view (function-based or class-based), you can check the URL that would be used as the “success url”.

We’d have to see the view in order to provide more specific advice.

3

Hi,
thank you for the answer. Here is the code that deletes the records and that has to redirect to the url to check:

class RecordDeleteView(PermissionRequiredMixin, generic.View):
    permission_required = ( "app.modify_rights", )

    def post(self, request, *args, **kwargs):
        ids_to_del = self.request.POST.getlist('id-to-del')
        current_path = self.request.POST.get('current-path')
        #current_path is something like /path/?firstparameter=1&secondparameter=2&page=2
        if ids_to_del:
            Record.objects.filter(id__in=ids_to_del).delete()
        #Here it would be perfect to check if the link is still working   
        return HttpResponseRedirect(current_path)
4

Using that structure (data in query variables and not in the path) as your path means that the path itself is valid - it’s the variables that need to be checked.

You would need to verify that all of firstparameter, secondparameter, and page are going to be valid at that point.

1 Like
5

To check if the page is valid after the deletion, I ended up subclassing “Paginator” and overriding the “validate_number” method. If the page is not found, the last page will be displayed.

class SafePaginator(Paginator):
    def validate_number(self, number):
        try:
            return super().validate_number(number)
        except EmptyPage:
            if number > 1:
                return self.num_pages
            else:
                raise

sources:
https://stackoverflow.com/questions/40835222/display-last-page-of-paginated-results-instead-of-404-using-listview/40835335
https://github.com/encode/django-vanilla-views/issues/49