AbstractDocumentMetadata

Interface for application metadata for a Document.

Objects returned in Document.metadata must implement this interface.

The way application-level metadata works changed in a significant way in the release 0.97.0. If you first started to use this interface before release, please read the following information carefully.

Starting in 0.97.0 the data stored in this object is purely for application use, Multipaz library itself only maintains this object, but does not use it. Fields that existed in 0.96.0 and earlier except for other, have been moved to the Document object itself; the other field now corresponds to this object.

If the data table that used for persistent storage DocumentStore (Document.defaultTableSpec by default) contains data compatible with 0.96.0, it must be migrated going to 0.97.0+. Multipaz provides some migration support in two important cases but only if DocumentStore uses the default table. You you use a custom table, you'll need to do migration yourself.

Here are the supported migration paths:

• If you used DocumentMetadata object directly or through delegation in 0.96.0 or before, Multipaz will update the table data automatically. The data in other field in DocumentMetadata will be passed to the factory function that you set in DocumentStore.Builder.setDocumentMetadataFactory, if other was not null, this function must be provided.

• If you had your own serialization for AbstractDocumentMetadata, and that serialization is not CBOR map with provisioned field, that serialization will be passed to the factory function. It is your application's responsibility to update fields in the Document object after the migration (since Multipaz migration code cannot parse your custom serialization).

• In all other cases, you have to create fully custom migration implementation. You must set Document.customSchema0_97_0_MigrationFn before creating the DocumentStore. This migration function will be invoked for each document only when the migration is needed; old serialized data will be passed in, this function must return new serialized data structured as serialized CBOR map with the fields as defined in org.multipaz.document.DocumentData as it is defined in the release 0.97.0 (this object may change in the future releases, but migration to from 0.97.0 to the future release will be handled by Multipaz).

In all cases, make sure to test your migration well.