Copying, Templating, and Updating Resources

Resources have a “template type” and “template version” accessed with templateType and templateVersion. This allows resources that provide user- or developer-specified schemas to indicate the name and version number of a schema; that information can be used to

• update resources when new versions of the schema are released;

• inform users and applications that the resource conforms to a standard structure; and

• provide information to applications on how a resource is intended to be used.

This template information allows resources to model prototypal inheritance (where one document’s structure serves as the “theme” or “style” for other documents – similar to the way most presentation software allows users to create and edit slide styles). Thus, resources may be

• cloned (which produces a new “blank” resource that has its own UUID but with ancillary data matching the source’s ancillary data); or

• copied (which produces a new resource that has a different UUID and different component UUIDs but whose content matches the source document); or

• updated (which produces a new resource whose UUIDs match the source but whose template version has been updated).

See the clone, copyInitialize, and copyFinalize methods for details on how to carry these tasks out. Note that, as with supports for template type and version information, the ability to clone and copy resources must be implemented by subclasses of the base resource class. Some facilties are provided for you to copy information such as property data, link data, unit systems, etc.