Managing Versions of a Resource

Enabling Auto Versioning of Resources

Resources can be automatically versioned when they are added or updated. But this feature is disabled by default. It can be enabled by adding following to CARBON_HOME/repository/conf/registry.xml

    <versionResourcesOnChange>true</versionResourcesOnChange>

But collections are not versioned automatically due to performance considerations.

Creating Versions of Resources

However, you can create versions of collections or resources using the API. It is recommended that collection versions are created only for making checkpoints of the sub-tree you are working on. When connecting to the server from the client side, it is possible to create versions.

Use the following command to create a version of your resource/collection:

registry.createVersion("/c1/c2");

Retrieving Versions of a Given Resource

You can list all of the versions of a given resource using the code given below. The result would be an array of String type, containing links to the different versions of the resource.

String [] versions = registry.getVersions("/c1/c2");

Restoring to an Old Version 

Since the Registry comes with versioning, we can restore a resource to any of its versions. This can be done using the registry as well. In the Retrieving Versions of a Given Resource section, we discussed how to retrieve versions for a give resource. The following line of code demonstrates we can restore back an old version of the registry instance. Please note that in the process of restoration, the content, properties, comments, tags, ratings, associations and dependencies will be restored but subscriptions and permissions related to resources won't be restored.

registry.restoreVersion ("/c1/c2;version:2");

See also Managing Metadata to learn how to check versions using the Management Console.