add missing packages

src/pretix/storefrontapi/serializers.py

@@ -0,0 +1,30 @@
+from i18nfield.fields import I18nCharField, I18nTextField
+from rest_framework.fields import Field
+from rest_framework.serializers import ModelSerializer
+
+
+class I18nFlattenedField(Field):
+    def __init__(self, **kwargs):
+        self.allow_blank = kwargs.pop("allow_blank", False)
+        self.trim_whitespace = kwargs.pop("trim_whitespace", True)
+        self.max_length = kwargs.pop("max_length", None)
+        self.min_length = kwargs.pop("min_length", None)
+        super().__init__(**kwargs)
+
+    def to_representation(self, value):
+        return str(value)
+
+    def to_internal_value(self, data):
+        raise TypeError("Input not supported.")
+
+
+class I18nFlattenedModelSerializer(ModelSerializer):
+    pass
+
+
+I18nFlattenedModelSerializer.serializer_field_mapping[I18nCharField] = (
+    I18nFlattenedField
+)
+I18nFlattenedModelSerializer.serializer_field_mapping[I18nTextField] = (
+    I18nFlattenedField
+)