feat: Add support for LazyReferenceField.

Author: zrlay

graphene_mongo/converter.py

@@ -114,3 +114,20 @@ def dynamic_type():
         return Field(_type, description=get_field_description(field, registry))
 
     return Dynamic(dynamic_type)
+
+
+@convert_mongoengine_field.register(mongoengine.LazyReferenceField)
+def convert_lazy_field_to_dynamic(field, registry=None):
+    model = field.document_type
+
+    def lazy_resolver(root, *args, **kwargs):
+        if getattr(root, field.name or field.db_name):
+            return getattr(root, field.name or field.db_name).fetch()
+
+    def dynamic_type():
+        _type = registry.get_type_for_model(model)
+        if not _type:
+            return None
+        return Field(_type, resolver=lazy_resolver, description=get_field_description(field, registry))
+
+    return Dynamic(dynamic_type)

graphene_mongo/tests/models.py

@@ -4,14 +4,20 @@
 )
 from mongoengine.fields import (
     DateTimeField, EmailField, EmbeddedDocumentField,
-    FloatField, EmbeddedDocumentListField, ListField,
+    FloatField, EmbeddedDocumentListField, ListField, LazyReferenceField,
     MapField, PointField, ReferenceField, StringField,
     MultiPolygonField
 )
 
 connect('graphene-mongo-test', host='mongomock://localhost', alias='default')
 
 
+class Publisher(Document):
+
+    meta = {'collection': 'test_publisher'}
+    name = StringField()
+
+
 class Editor(Document):
     """
     An Editor of a publication.
@@ -22,6 +28,7 @@ class Editor(Document):
     first_name = StringField(required=True, help_text="Editor's first name.", db_field='fname')
     last_name = StringField(required=True, help_text="Editor's last name.")
     metadata = MapField(field=StringField(), help_text="Arbitrary metadata.")
+    company = LazyReferenceField(Publisher)
 
 
 class Article(Document):

graphene_mongo/tests/test_converter.py

@@ -10,7 +10,7 @@
 from .models import (
     Article, Editor, EmbeddedArticle, Player, Reporter,
     ProfessorMetadata, ProfessorVector,
-)
+    Publisher)
 from .. import registry
 from ..converter import convert_mongoengine_field
 from ..fields import MongoengineConnectionField
@@ -117,6 +117,23 @@ class Meta:
     assert graphene_type.type == E
 
 
+def test_should_lazy_reference_convert_dynamic():
+
+    class P(MongoengineObjectType):
+
+        class Meta:
+            model = Publisher
+            interfaces = (Node,)
+
+    dynamic_field = convert_mongoengine_field(
+        Editor._fields['company'], P._meta.registry)
+
+    assert isinstance(dynamic_field, Dynamic)
+    graphene_type = dynamic_field.get_type()
+    assert isinstance(graphene_type, graphene.Field)
+    assert graphene_type.type == P
+
+
 def test_should_embedded_convert_dynamic():
 
     class PM(MongoengineObjectType):

graphene_mongo/tests/types.py

@@ -5,8 +5,14 @@
     Article, Editor, EmbeddedArticle, Player, Reporter,
     Parent, Child, ProfessorMetadata, ProfessorVector,
     ParentWithRelationship, ChildRegisteredBefore,
-    ChildRegisteredAfter, CellTower
-)
+    ChildRegisteredAfter, CellTower,
+    Publisher)
+
+
+class PublisherType(MongoengineObjectType):
+
+    class Meta:
+        model = Publisher
 
 
 class EditorType(MongoengineObjectType):
@@ -69,6 +75,13 @@ class Meta:
         model = ProfessorVector
 
 
+class PublisherNode(MongoengineObjectType):
+
+    class Meta:
+        model = Publisher
+        interfaces = (Node,)
+
+
 class ArticleNode(MongoengineObjectType):
 
     class Meta:

graphene_mongo/utils.py

@@ -22,7 +22,7 @@ def get_model_reference_fields(model, excluding=None):
     attributes = dict()
     for attr_name, attr in model._fields.items():
         if attr_name in excluding \
-                or not isinstance(attr, mongoengine.fields.ReferenceField):
+                or not isinstance(attr, (mongoengine.fields.ReferenceField, mongoengine.fields.LazyReferenceField)):
             continue
         attributes[attr_name] = attr
     return attributes