Document versioning overview

A document version is created when a document is checked in to an object store. Each version of the document represents the document as it existed when it was checked in, and is individually saved and maintained. A version is a document object that is an instance of the document class or one of its subclasses. All versions of a document are referred to as the version series.

You can access content and metadata of a specific version and, if necessary, track the changes that have been applied from one version to the next. However, not every change is reflected in the version. For instance:

• If you change the value of a particular property more than once on a particular version, only the last applied property value is preserved. A new version is not required for each change.
• While you are editing a checked out version, you can save the document content many times before checking in the finished document. The version does not maintain a history of these interim saves. The version preserves only the content as it existed when checked in.
• The check-out list operates only on reservation objects.

Document versioning is enabled and disabled at the document class, not on individual documents. Document versioning is enabled for the class by default. If you create a document that uses a class with versioning disabled, that document is permanently non-versionable, it can never be checked out, and it cannot be converted into a document with versioning enabled. There is always only one document version in its version series.

When versioning is disabled, you can still change any modifiable custom properties that were assigned to the document class. An example might be a description field; you can change the value of this description field, but this change does not create a version of the document. The effect of such a change, of course, is that no record of the change is maintained anywhere in the document properties or version history.

If a document with versioning disabled is a minor version, you can promote it to a major version. Conversely, if it is a major version, you can demote it to a minor version.

Changing the versioning-enabled setting for a class (in either direction) does not affect existing document instances. In other words, the versionability of a document series is set at the time the initial version is created and never changes.