Page History

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An overview of the version history, including links to older versions of an item, is available at the bottom of an Item View page. The repository administrator can decide whether the version history should be available to all users or restricted to administrators.

Architecture

Versioning model

For every new Version a separate DSpace Item will be created that replicates the metadata, bundle and bitstream records. The bitstream records will point to the same file on the disk.

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The Cleanup method has been modified to retain the file if another Bitstream record point to it, in other words the file will be deleted only if the Bitstream record processed is the only one to point to the file (count(INTERNAL_ID)=1).

Services to support Versioning and Alternative Identifiers.

DSpace Item Versioning will be encapsulated as an Extensible Service that may be reimplemented by the local repository maintainers to produce alternate versioning behaviors and Identifier Schemes. Versioning Services layer on top of IdentifierServices dedicated to Encoding, Resolution, Minting and Registration of Identifiers for specific DSpace Items and Bitstreams.  It is through this highly extensible layering of functionality where local developers can alter the versioning behavior and introduce their own local enhancements.  The DSpace Service Manager, based on the Spring Framework, provides the key leverage for this flexibility.

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Versioning Service

The Versioning Service will be responsible for the replication of one or more Items when a new version is requested.  The new version will not yet be preserved in the Repository, it will be preserved when the databases transactional window is completed, thus when errors arise in the versioning process, the database will be properly kept in its original state and the application will alert that an exception has occurred that is in need of correction.

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public interface VersioningService {

    Version createNewVersion(Context c, int itemId);

    Version createNewVersion(Context c, int itemId, String summary);

    void removeVersion(Context c, int versionID);

    void removeVersion(Context c, Item item);

    Version getVersion(Context c, int versionID);

    Version restoreVersion(Context c, int versionID);

    Version restoreVersion(Context c, int versionID, String summary);

    VersionHistory findVersionHistory(Context c, int itemId);

    Version updateVersion(Context c, int itemId, String summary);

    Version getVersion(Context c, Item item);
}

Identifier Service

The Identifier Service maintains an extensible set of IdentifierProvider services that are responsible for two important activities in Identifier management:

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