fix(compat): Use ForeignObjectRel.hidden field from django 5.1

Refs #719

modeltranslation/_compat.py

@@ -0,0 +1,18 @@
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+
+import django
+
+if TYPE_CHECKING:
+    from django.db.models.fields.reverse_related import ForeignObjectRel
+
+
+def is_hidden(field: ForeignObjectRel) -> bool:
+    return field.hidden
+
+
+if django.VERSION <= (5, 1):
+
+    def is_hidden(field: ForeignObjectRel) -> bool:
+        return field.is_hidden()

modeltranslation/fields.py

@@ -23,6 +23,7 @@
 from modeltranslation.widgets import ClearableWidgetWrapper
 
 from ._typing import Self
+from ._compat import is_hidden
 
 SUPPORTED_FIELDS = (
     fields.CharField,
@@ -187,7 +188,7 @@ def __init__(
                 or self.remote_field.model == self.model
             ):
                 self.remote_field.related_name = "%s_rel_+" % self.name
-            elif self.remote_field.is_hidden():
+            elif is_hidden(self.remote_field):
                 # Even if the backwards relation is disabled, django internally uses it, need to use a language scoped related_name
                 self.remote_field.related_name = "_%s_%s_+" % (
                     self.model.__name__.lower(),
@@ -218,7 +219,7 @@ def __init__(
             if hasattr(self.remote_field.model._meta, "_related_objects_cache"):
                 del self.remote_field.model._meta._related_objects_cache
 
-        elif self.remote_field and not self.remote_field.is_hidden():
+        elif self.remote_field and not is_hidden(self.remote_field):
             current = self.remote_field.get_accessor_name()
             # Since fields cannot share the same rel object:
             self.remote_field = copy.copy(self.remote_field)

modeltranslation/translator.py

@@ -40,6 +40,7 @@
 # Re-export the decorator for convenience
 from modeltranslation.decorators import register
 
+from ._compat import is_hidden
 from ._typing import _ListOrTuple
 
 __all__ = [
@@ -599,7 +600,7 @@ def _register_single_model(self, model: type[Model], opts: TranslationOptions) -
                 setattr(model, field.get_attname(), desc)
 
                 # Set related field names on other model
-                if not field.remote_field.is_hidden():
+                if not is_hidden(field.remote_field):
                     other_opts = self._get_options_for_model(field.remote_field.model)
                     other_opts.related = True
                     other_opts.related_fields.append(field.related_query_name())