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Ralf Claussnitzer edited this page Feb 13, 2015 · 13 revisions

What is the Qucosa SWORD File Handler?

The Qucosa SWORD File Handler provides a new media type application/vnd.qucosa.mets+xml and a set of SWORD collections and entries to control Fedora 3 object properties. It extends the ingesting mechanism of the Fedora 3 SWORD implementation provided by SLUB.

What is SWORD?

SWORD is a lightweight protocol for depositing content from one location to another. It stands for Simple Web-service Offering Repository Deposit and is a profile of the Atom Publishing Protocol (known as APP or ATOMPUB).

The SWORD protocol provides extended AtomPub semantics for ingesting resources into repositories, such as Package Support and Nested Service Description. What media and media formats are supported is determined by mime-type and Packaging Header. The argument goes that the media type alone is not sufficient for the service to determine how to handle a particular submission. That's why SWORD defines the packaging handling mechanism, which in turn lead to re-inventing the Content Negotiation mechanism that is defined in HTTP already, using just media types.

This is not called "format negotiation" because the alternate representations may be of the same media type, but use different capabilities of that type, be in different languages, etc.

The SWORD protocol defines the an HTTP protocol implementation to post content for deposit in repositories. A SWORD service document defines collections and acceptable media types for this collections. Given a client posts content of an accepted media type the receiving repository service should know how to handle that content. The SWORD service implementation - an actual fork of http://sourceforge.net/projects/sword-app/ - supports an extensible set of file handlers to handle particular media types (and package formats).

Why a custom media type?

The Qucosa Repository Project uses a Fedora Repository and several auxiliary services. However, Fedora's data model is not restricting the form of digital assets, how they are created and updated. That's totally application specific. The application/vnd.qucosa.mets+xml media type defines a vendor specific data format and protocol for the Qucosa Repository that is understood by the Qucosa SWORD File Handler.