Add support for localized query look ups

localized_fields/__init__.py

@@ -0,0 +1 @@
+default_app_config = 'localized_fields.apps.LocalizedFieldsConfig'

localized_fields/apps.py

@@ -1,5 +1,21 @@
+import inspect
+
 from django.apps import AppConfig
+from django.conf import settings
+
+from . import lookups
+from .fields import LocalizedField
+from .lookups import LocalizedLookupMixin
 
 
 class LocalizedFieldsConfig(AppConfig):
     name = 'localized_fields'
+
+    def ready(self):
+        if getattr(settings, 'LOCALIZED_FIELDS_EXPERIMENTAL', False):
+            for _, clazz in inspect.getmembers(lookups):
+                if not inspect.isclass(clazz) or clazz is LocalizedLookupMixin:
+                    continue
+
+                if issubclass(clazz, LocalizedLookupMixin):
+                    LocalizedField.register_lookup(clazz)

localized_fields/lookups.py

@@ -0,0 +1,80 @@
+from django.conf import settings
+from django.contrib.postgres.fields.hstore import KeyTransform
+from django.contrib.postgres.lookups import (SearchLookup, TrigramSimilar,
+                                             Unaccent)
+from django.db.models.expressions import Col
+from django.db.models.lookups import (Contains, EndsWith, Exact, IContains,
+                                      IEndsWith, IExact, In, IRegex, IsNull,
+                                      IStartsWith, Regex, StartsWith)
+from django.utils import translation
+
+
+class LocalizedLookupMixin():
+    def process_lhs(self, qn, connection):
+        if isinstance(self.lhs, Col):
+            language = translation.get_language() or settings.LANGUAGE_CODE
+            self.lhs = KeyTransform(language, self.lhs)
+        return super().process_lhs(qn, connection)
+
+    def get_prep_lookup(self):
+        return str(self.rhs)
+
+
+class LocalizedSearchLookup(LocalizedLookupMixin, SearchLookup):
+    pass
+
+
+class LocalizedUnaccent(LocalizedLookupMixin, Unaccent):
+    pass
+
+
+class LocalizedTrigramSimilair(LocalizedLookupMixin, TrigramSimilar):
+    pass
+
+
+class LocalizedExact(LocalizedLookupMixin, Exact):
+    pass
+
+
+class LocalizedIExact(LocalizedLookupMixin, IExact):
+    pass
+
+
+class LocalizedIn(LocalizedLookupMixin, In):
+    pass
+
+
+class LocalizedContains(LocalizedLookupMixin, Contains):
+    pass
+
+
+class LocalizedIContains(LocalizedLookupMixin, IContains):
+    pass
+
+
+class LocalizedStartsWith(LocalizedLookupMixin, StartsWith):
+    pass
+
+
+class LocalizedIStartsWith(LocalizedLookupMixin, IStartsWith):
+    pass
+
+
+class LocalizedEndsWith(LocalizedLookupMixin, EndsWith):
+    pass
+
+
+class LocalizedIEndsWith(LocalizedLookupMixin, IEndsWith):
+    pass
+
+
+class LocalizedIsNullWith(LocalizedLookupMixin, IsNull):
+    pass
+
+
+class LocalizedRegexWith(LocalizedLookupMixin, Regex):
+    pass
+
+
+class LocalizedIRegexWith(LocalizedLookupMixin, IRegex):
+    pass