I wanted to briefly post a Content Model for the repository. This is the “Common Metadata” Content Model, and it has been adapted from the Hydra Project. A digital object can be associated with a content model before, during or after ingestion. The content model in turn can point to a Service Definition object, which defines certain services for the digital object. Those service are in turn specifically defined in a Service Deployment object. The SDep object defines these services with the Web Services Description Language (WSDL). WSDL is an XML format for specifically detailing a web service. Documentation for Fedora 3 states that “Notably, Fedora currently only supports performing disseminations via HTTP GET.” This should be fine for our purposes, and it should make our .wsdl file pretty straightforward.
This is certainly a lot of layers involved in making Fedora really do something, but the modularity is key when you need to make changes on your server. If the port designations for your server have changed, you only need to change a few .wsdl files. If you need to assign new services to a new type of digital object, just add those service definitions to your content model. At least, I hope it’s that simple.
<?xml version="1.0" encoding="UTF-8"?> <foxml:digitalObject VERSION="1.1" PID="gcm-cModel:commonMetadata" xmlns:foxml="info:fedora/fedora-system:def/foxml#" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="info:fedora/fedora-system:def/foxml# http://www.fedora.info/definitions/1/0/foxml1-1.xsd"> <foxml:objectProperties> <foxml:property NAME="info:fedora/fedora-system:def/model#state" VALUE="Active"/> <foxml:property NAME="info:fedora/fedora-system:def/model#label" VALUE="Common metadata model"/> <foxml:property NAME="info:fedora/fedora-system:def/model#ownerId" VALUE="fedoraAdmin"/> </foxml:objectProperties> <foxml:datastream ID="RELS-EXT" STATE="A" CONTROL_GROUP="X" VERSIONABLE="true"> <foxml:datastreamVersion ID="RELS-EXT.0" LABEL="External relations" MIMETYPE="text/xml" SIZE="448"> <foxml:xmlContent> <rdf:RDF xmlns:fedora-model="info:fedora/fedora-system:def/model#" xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"> <rdf:Description rdf:about="info:fedora/gcm-cModel:commonMetadata"> <fedora-model:hasModel rdf:resource="info:fedora/fedora-system:ContentModel-3.0"></fedora-model:hasModel> <!-- A key line here. This says that objects associated with this Content Model will have this service. In this case, since this is a "Common Metadata" Content Model, the service it points to is "gcm-sDef:commonMetadata." --> <fedora-model:hasService rdf:resource="info:fedora/gcm-sDef:commonMetadata"></fedora-model:hasService> </rdf:Description> </rdf:RDF> </foxml:xmlContent> </foxml:datastreamVersion> </foxml:datastream> <foxml:datastream ID="DS-COMPOSITE-MODEL" STATE="A" CONTROL_GROUP="X" VERSIONABLE="true"> <foxml:datastreamVersion ID="DS-COMPOSITE-MODEL.0" LABEL="DS composite model" MIMETYPE="text/xml" SIZE="780"> <foxml:xmlContent> <dsCompositeModel xmlns="info:fedora/fedora-system:def/dsCompositeModel#"> <dsTypeModel ID="DC"> <form MIME="text/xml"></form> </dsTypeModel> <dsTypeModel ID="RELS-EXT"> <form MIME="text/xml"></form> </dsTypeModel> <dsTypeModel ID="descMetadata"> <form MIME="text/xml"></form> </dsTypeModel> </dsCompositeModel> </foxml:xmlContent> </foxml:datastreamVersion> </foxml:datastream> </foxml:digitalObject>
This content model points to one service call (info:fedora/gcm-sDef:commonMetadata). This service definition object will (through a SDep) deliver metadata common to all the objects in the repository: title, type (from the DCMI vocabulary), type (from our own categories), creation date and general description.
Finally, this content model is missing two compulsory datastreams, a basic Dublin Core datastream and an auditing one. These are added by Fedora automatically when the object is ingested.