Ticket #24858: get_FIELD_display.patch

django/contrib/postgres/fields/array.py

@@ -1 +1 @@
 import json
+import collections
 
 from django.contrib.postgres import lookups
 from django.contrib.postgres.forms import SimpleArrayField
@@ -160 +161 @@
         defaults.update(kwargs)
         return super(ArrayField, self).formfield(**defaults)
 
+    def _get_flatchoices(self):
+        flat = []
+        for choice, value in self.choices:
+            if isinstance(value, (list, tuple)):
+                flat.extend(value)
+            elif isinstance(choice, collections.Hashable):
+                flat.append((choice, value))
+            elif isinstance(choice, list):
+                flat.append((tuple(choice), value))
+        return flat
+
+    def _get_hashable(self, value):
+        if isinstance(value, collections.Hashable):
+            return value
+        elif isinstance(value, list):
+            return tuple(value)
+        else:
+            raise ValueError('Unexpected unhashable type')
+
+    flatchoices = property(_get_flatchoices)
+
 
 @ArrayField.register_lookup
 class ArrayContains(lookups.DataContains):

django/db/models/base.py

@@ -3 +3 @@
 import copy
 import inspect
 import warnings
+import collections
 from itertools import chain
 
 from django.apps import apps
@@ -839 +840 @@
 
     def _get_FIELD_display(self, field):
         value = getattr(self, field.attname)
+        if not isinstance(value, collections.Hashable):
+            try:
+                value = field._get_hashable(value)
+            except:
+                raise ValueError('Value hashing failed')
         return force_text(dict(field.flatchoices).get(value, value), strings_only=True)
 
     def _get_next_or_previous_by_FIELD(self, field, is_next, **kwargs):