Make country optional and show most common countries

With country mandatory we see people picking something from the top of
the list, probably just because it's easy or because they don't want to
share their country.

To deal with the first, modify the country selection so that it first
shows the most common countries used for this conference, and only later
the full list of countries. The initial list of countries under "common
countries" can be specified at the conference configuration, and will then
gradually be replaced with the actual countries of the attendees.

To deal with the second, make the country field optional.

1 files changed, 22 insertions, 0 deletions

diff --git a/postgresqleu/util/backendlookups.py b/postgresqleu/util/backendlookups.py
index 4392b3c8..136cbbfa 100644
--- a/postgresqleu/util/backendlookups.py
+++ b/postgresqleu/util/backendlookups.py
@@ -59,3 +59,25 @@ class GeneralAccountLookup(LookupBase):
                 Q(username__icontains=query) | Q(first_name__icontains=query) | Q(last_name__icontains=query)
             )[:30]
         ]
+
+
+class CountryLookup(LookupBase):
+    @property
+    def url(self):
+        return '/events/admin/lookups/country/'
+
+    @property
+    def label_from_instance(self):
+        return lambda x: x.printable_name
+
+    @classmethod
+    def get_values(self, query):
+        return [
+            {
+                'id': c.iso,
+                'value': c.printable_name,
+            }
+            for c in Country.objects.filter(
+                Q(printable_name__icontains=query) | Q(iso__icontains=query)
+            )[:30]
+        ]