Move SyncedDataMixin from extras to core

netbox/core/forms/mixins.py

@@ -0,0 +1,25 @@
+from django import forms
+from django.utils.translation import gettext as _
+
+from core.models import DataFile, DataSource
+from utilities.forms.fields import DynamicModelChoiceField
+
+__all__ = (
+    'SyncedDataMixin',
+)
+
+
+class SyncedDataMixin(forms.Form):
+    data_source = DynamicModelChoiceField(
+        queryset=DataSource.objects.all(),
+        required=False,
+        label=_('Data source')
+    )
+    data_file = DynamicModelChoiceField(
+        queryset=DataFile.objects.all(),
+        required=False,
+        label=_('File'),
+        query_params={
+            'source_id': '$data_source',
+        }
+    )