Merge pull request #38 from cloudblue/fix/LITE-21793

LITE-21793 Fixed DRF dependency

Author: maxipavlovic

dj_rql/filter_cls.py

@@ -27,7 +27,6 @@
     SUPPORTED_FIELD_TYPES,
     SearchOperators,
 )
-from dj_rql.drf.fields import SelectField
 from dj_rql.exceptions import RQLFilterLookupError, RQLFilterParsingError, RQLFilterValueError
 from dj_rql.openapi import RQLFilterClassSpecification
 from dj_rql.parser import RQLParser
@@ -40,6 +39,12 @@
 
 from lark.exceptions import LarkError
 
+try:
+    from dj_rql.drf.fields import SelectField
+except ImportError:
+    SelectField = None  # pragma: no cover
+
+
 iterable_types = (list, tuple)
 
 
@@ -281,7 +286,7 @@ def build_q_for_filter(self, data):
             filter_name, operator, str_value, available_lookups, null_values,
         )
         django_field = base_item.get('field')
-        if django_field and isinstance(django_field, SelectField):
+        if django_field and SelectField and isinstance(django_field, SelectField):
             raise RQLFilterLookupError(**self._get_error_details(
                 filter_name, filter_lookup, str_value,
             ))