Another important feature demonstrated by the Quincy Funds repositories is the ability to serve SQL repository item properties as org.w3c.Document objects. (org.w3c.Documents are implementations of the Document Object Model standard for XML documents; for more information, refer to the Document Object Model Level 2 Core specification at http://www.w3.org/DOM/DOMTR.) Content stored in the repository as a String or File can be transformed into an org.w3c.Document by means of the property descriptor classes atg.xml.FileToDOMPropertyDescriptor and atg.xml.StringToDOMPropertyDescriptor (both are extensions of atg.repository.RepositoryPropertyDescriptor). The properties can then be used as input to the XMLTransform servlet bean, for instance. For more information on the XMLTransform servlet bean, refer to the ATG Page Developer's Guide. For more information on using property descriptors, refer to User-Defined Property Types in the ATG Repository Guide.
Caching capability is also provided for org.w3c.Documents created through property descriptors. org.w3c.Documents served from XML repositories are cached using a cache key that is based on either a file name or URL. The ability to create org.w3c.Documents through SQL property descriptors, as described above, requires a different cache key, because the property descriptors, in particular atg.xml.StringToDOMPropertyDescriptor, do not have file or URL information. The cache key used by the property descriptors for document caching is based on a concatenation of the repository item’s repository name, item descriptor name, repository id, and content property name.
