Allow custom submit buttons to return a HttpResponse

And if they do, return this immediately instead of continuing to process
the submit.

1 files changed, 6 insertions, 1 deletions

diff --git a/postgresqleu/util/backendviews.py b/postgresqleu/util/backendviews.py
index aa9ec34b..e1eb614b 100644
--- a/postgresqleu/util/backendviews.py
+++ b/postgresqleu/util/backendviews.py
@@ -152,7 +152,12 @@ def backend_process_form(request, urlname, formclass, id, cancel_url='../', save
                 # We do!
                 f = form.fields[k[10:]]
                 if f.callback:
-                    f.callback(request)
+                    r = f.callback(request)
+                    # If the callback returns a HttpResponse
+                    # (typically a redirect), return that immediately
+                    # (without saving the form).
+                    if isinstance(r, HttpResponse):
+                        return r
                 return HttpResponseRedirect(".")
 
         if form.is_valid():