Method _fetch_objects

mongoengine/dereference.py:164–207

Fetch all references and convert to their document objects

(self, doc_type=None)

        return reference_map

    def _fetch_objects(self, doc_type=None):
        """Fetch all references and convert to their document objects"""
        object_map = {}
        for collection, dbrefs in self.reference_map.items():
            # we use getattr instead of hasattr because hasattr swallows any exception under python2
            # so it could hide nasty things without raising exceptions (cfr bug #1688))
            ref_document_cls_exists = getattr(collection, "objects", None) is not None

            if ref_document_cls_exists:
                col_name = collection._get_collection_name()
                refs = [
                    dbref for dbref in dbrefs if (col_name, dbref) not in object_map
                ]
                references = collection.objects.in_bulk(refs)
                for key, doc in references.items():
                    object_map[(col_name, key)] = doc
            else:  # Generic reference: use the refs data to convert to document
                if isinstance(doc_type, (ListField, DictField, MapField)):
                    continue

                refs = [
                    dbref for dbref in dbrefs if (collection, dbref) not in object_map
                ]

                if doc_type:
                    references = doc_type._get_db()[collection].find(
                        {"_id": {"$in": refs}}
                    )
                    for ref in references:
                        doc = doc_type._from_son(ref)
                        object_map[(collection, doc.id)] = doc
                else:
                    references = get_db()[collection].find({"_id": {"$in": refs}})
                    for ref in references:
                        if "_cls" in ref:
                            doc = get_document(ref["_cls"])._from_son(ref)
                        elif doc_type is None:
                            doc = get_document(
                                "".join(x.capitalize() for x in collection.split("_"))
                            )._from_son(ref)
                        else:
                            doc = doc_type._from_son(ref)
                        object_map[(collection, doc.id)] = doc
        return object_map

    def _attach_objects(self, items, depth=0, instance=None, name=None):
        """