Reference field

Work with references.

class RDoc(Document):
    i = fields.IntegerField()

class Doc(Document):
    rdoc = fields.ReferenceField(RDoc)

rdoc = RDoc()
rdoc.i = 13
db.insert(rdoc)

doc = Doc()
doc.rdoc = rdoc
db.insert(doc)

doc = db.get_queryset(Doc).find_one(doc.id)  # reload doc
assert doc.rdoc.id == rdoc.id
assert doc.rdoc.i == 13

Or with asyncio:

rdoc = await doc.rdoc
assert rdoc.id == rdoc.id
assert rdoc.i == 13
assert doc.rdoc == rdoc.id
exception yadm.fields.reference.BrokenReference

Raise if referrenced document is not found.

exception yadm.fields.reference.NotBindingToDatabase

Raise if set ObjectId insted referenced document to new document, who not binded to database.

class yadm.fields.reference.Reference(_id: bson.objectid.ObjectId, parent: yadm.documents.DocumentItemMixin, field: yadm.fields.reference.ReferenceField)

Reference object.

This is awaitable:

doc = await doc.reference
class yadm.fields.reference.ReferenceField(reference_document_class, **kwargs)

Field for work with references.

Parameters:reference_document_class – class for refered documents
copy()

Return copy of field.

from_mongo(document, value)

Convert mongo value to python value.

Parameters:
  • document (BaseDocument) – document
  • value – mongo value
Returns:

python value
get_default(document)

Return default value.

get_fake(document, faker, depth)

Try create referenced document.

prepare_value(document, value)

The method is called when value is assigned for the attribute.

Parameters:
Returns:

prepared value

It must be accept value argument and return processed (e.g. casted) analog. Also it is called once for the default value.

to_mongo(document, value)

Convert python value to mongo value.

Parameters:
  • document (BaseDocument) – document
  • value – python value
Returns:

mongo value