Add logic for custom resolvers.

Description:
This commit adds logic to use custom user resolvers instead of
using only default manager queryset.

Signed-off-by: Pavel Kirilin <[email protected]>

graphene_django_extras/fields.py

@@ -138,7 +138,7 @@ def list_resolver(manager, filterset_class, filtering_args, root, info, **kwargs
                 qs = None
 
         if qs is None:
-            qs = queryset_factory(manager, info.field_nodes, info.fragments, **kwargs)
+            qs = queryset_factory(manager, root, info, **kwargs)
             qs = filterset_class(
                 data=filter_kwargs, queryset=qs, request=info.context
             ).qs
@@ -228,14 +228,14 @@ def __init__(
     def model(self):
         return self.type.of_type._meta.node._meta.model
 
-    def get_queryset(self, manager, info, **kwargs):
-        return queryset_factory(manager, info.field_nodes, info.fragments, **kwargs)
+    def get_queryset(self, manager, root, info, **kwargs):
+        return queryset_factory(manager, root, info, **kwargs)
 
     def list_resolver(
         self, manager, filterset_class, filtering_args, root, info, **kwargs
     ):
         filter_kwargs = {k: v for k, v in kwargs.items() if k in filtering_args}
-        qs = self.get_queryset(manager, info, **kwargs)
+        qs = self.get_queryset(manager, root, info, **kwargs)
         qs = filterset_class(data=filter_kwargs, queryset=qs, request=info.context).qs
 
         if root and is_valid_django_model(root._meta.model):
@@ -308,7 +308,7 @@ def list_resolver(
         self, manager, filterset_class, filtering_args, root, info, **kwargs
     ):
 
-        qs = queryset_factory(manager, info.field_nodes, info.fragments, **kwargs)
+        qs = queryset_factory(manager, root, info, **kwargs)
 
         filter_kwargs = {k: v for k, v in kwargs.items() if k in filtering_args}
 

graphene_django_extras/types.py

@@ -336,7 +336,7 @@ def BaseType(cls):
 
 class DjangoSerializerType(ObjectType):
     """
-        DjangoSerializerType definition
+    DjangoSerializerType definition
     """
 
     ok = Boolean(description="Boolean field that return mutation result request.")
@@ -611,9 +611,7 @@ def retrieve(cls, manager, root, info, **kwargs):
     @classmethod
     def list(cls, manager, filterset_class, filtering_args, root, info, **kwargs):
 
-        qs = queryset_factory(
-            cls._meta.queryset or manager, info.field_nodes, info.fragments, **kwargs
-        )
+        qs = queryset_factory(cls._meta.queryset or manager, root, info, **kwargs)
 
         filter_kwargs = {k: v for k, v in kwargs.items() if k in filtering_args}
 

graphene_django_extras/utils.py

@@ -167,7 +167,7 @@ def create_obj(django_model, new_obj_key=None, *args, **kwargs):
 
 def clean_dict(d):
     """
-        Remove all empty fields in a nested dict
+    Remove all empty fields in a nested dict
     """
 
     if not isinstance(d, (dict, list)):
@@ -246,6 +246,19 @@ def _get_queryset(klass):
     return manager.all()
 
 
+def _get_custom_resolver(info):
+    """
+    Get custom user defined resolver for query.
+
+    This resolver must return QuerySet instance to be successfully resolved.
+    """
+    parent = info.parent_type
+    custom_resolver_name = f"resolve_{to_snake_case(info.field_name)}"
+    if hasattr(parent.graphene_type, custom_resolver_name):
+        return getattr(parent.graphene_type, custom_resolver_name)
+    return None
+
+
 def get_Object_or_None(klass, *args, **kwargs):
     """
     Uses get() to return an object, or None if the object does not exist.
@@ -348,7 +361,7 @@ def recursive_params(
     return select_related, prefetch_related
 
 
-def queryset_factory(manager, fields_asts=None, fragments=None, **kwargs):
+def queryset_factory(manager, root, info, **kwargs):
 
     select_related = set()
     prefetch_related = set()
@@ -365,15 +378,20 @@ def queryset_factory(manager, fields_asts=None, fragments=None, **kwargs):
     select_related = list(select_related)
     prefetch_related = list(prefetch_related)
 
+    fields_asts = info.field_nodes
     if fields_asts:
         select_related, prefetch_related = recursive_params(
             fields_asts[0].selection_set,
-            fragments,
+            info.fragments,
             available_related_fields,
             select_related,
             prefetch_related,
         )
 
+    custom_resolver = _get_custom_resolver(info)
+    if custom_resolver is not None:
+        manager = custom_resolver(root, info, **kwargs)
+
     if select_related and prefetch_related:
         return _get_queryset(
             manager.select_related(*select_related).prefetch_related(*prefetch_related)