ObjectDocument

ObjectDocument is a conceptual data representation used in software engineering to encode the state of an object and its metadata into a document-like structure. It typically serves as an interchange format between in-memory objects and storage or messaging systems, especially in environments that favor document-oriented approaches and schema flexibility.

A typical ObjectDocument includes: an identifier, a type or class discriminator, a set of properties corresponding to the object's attributes, and optional metadata such as creation and modification timestamps, version numbers, and access controls. Complex properties may be represented as embedded documents or as references to other documents, allowing the preservation of object graphs to varying degrees of depth. The document may also include lifecycle information, such as whether the object is new, dirty, or deleted.

In practice, ObjectDocuments are used for persistence in document stores, serialization for network transmission, and event-sourced or CQRS architectures where object state is captured as a sequence of documents. They are usually schema-flexible, permitting fields to be added or removed without breaking existing data. Serialization formats commonly include JSON, BSON, XML, or YAML. Access to the encoded object is typically provided by a mapping layer that translates between in-memory objects and the document representation, with attention to identity management, reference resolution, and data security.

Limitations include potential ambiguity in schemas, data drift in schema-less stores, and challenges in maintaining referential integrity across documents. See also: document database, object-relational mapping, serialization.