feat(generic): add DateTimeIntervalCharField

apis_core/generic/fields.py

@@ -0,0 +1,23 @@
+from django.db.models import DateTimeField, CharField
+
+
+class StringDateTimeField(CharField):
+    """ A simple CharField, that populates datetime fields with its own value """
+    def pre_save(self, model_instance, add):
+        name = self.attname.removesuffix('_string')
+        value = getattr(model_instance, self.attname)
+        if hasattr(model_instance, f'{name}_datetime'):
+            setattr(model_instance, f'{name}_datetime', value)
+        if hasattr(model_instance, f'{name}_datetime_from'):
+            setattr(model_instance, f'{name}_datetime_from', value)
+        if hasattr(model_instance, f'{name}_datetime_to'):
+            setattr(model_instance, f'{name}_datetime_to', value)
+        return super().pre_save(model_instance, add)
+
+
+class DateTimeIntervalCharField:
+    def contribute_to_class(self, cls, name):
+        StringDateTimeField(max_length=255, blank=True, null=True).contribute_to_class(cls, f'{name}_string')
+        DateTimeField(editable=False, blank=True, null=True).contribute_to_class(cls, f'{name}_datetime')
+        DateTimeField(editable=False, blank=True, null=True).contribute_to_class(cls, f'{name}_datetime_from')
+        DateTimeField(editable=False, blank=True, null=True).contribute_to_class(cls, f'{name}_datetime_to')