A new DataCite Content Resolver
In September 2011 we announced the alpha version of DataCite's Content Resolver. Today, we are pleased to present a new version. This beta release is prepared in close collaboration with CrossRef. We think it is very important that the two largest DOI Registration Agencies work together in order to provide metadata services to DOI names. The service can be accessed at http://data.datacite.org.
The Content Resolver exposes the metadata stored in the DataCite Metadata Store (MDS) using multiple formats. It can also redirect to content hosted by DataCite participating data centres, thus it is possible to access data directly using a DOI.
The biggest changes in this release are:
- Extra user defined URLs per DOI,
- addition of citation formatting metadata based on Citation Style Language (http://citationstyles.org).
In general, there are two ways of using the Content Service: HTTP content negotiation or HTML links.
HTTP content negotiation
The HTTP content negotiation is documented in detail at http://crosscite.org/cn. CrossCite is a place where CrossRef and DataCite host their shared initiatives. The documentation explains HTTP content negotiation as implemented by both Registration Agencies and provides a list of supported MIME media types (which allow us to distinguish between supported types e.g. HTML vs. PDF).
An example application of HTTP content negotiation is a citation formatting service. You can try it at http://crosscite.org/citeproc. This service will accept DOIs from both CrossRef and DataCite. This is possible because CrossRef and DataCite support a shared, common metadata format. When you input a DOI into the formatting service, it doesn’t know where the DOI was registered. The service will make an HTTP content negotiation request to the global DOI resolver (http://dx.doi.org) specifying which format of the metadata should be returned in the HTTP
Accept header. The global DOI resolver will notice (
Accept header!) that this is not a regular DOI resolution request; it will turn to CrossRef or DataCite accordingly for the relevant metadata instead of redirecting to a landing page. The format of metadata is shared between both registration agencies so the formatting service can interpret it without knowledge of DOI origin.
The DataCite Content Resolver can be also used with special HTML links containing MIME media types and DOIs. They are useful when HTTP content negotiation is not practical, namely when you want to use DOIs as hyperlinks in web pages. It’s important to note that HTTP content negotiation works on a global DOI resolver level but HTML links are DataCite Content Resolver service specific.
An example of an HTML link will be presented based on one of our DOIs: 10.5284/1015681. This DOI links to grey literature and it has a PDF associated with it. If you use the link: http://data.datacite.org/text/html/10.5284/1015681 you will be presented with an HTML rendering of the DOI’s metadata (text/html is MIME type for HTML pages). Alternatively you could link directly to the PDF associated with this DOI: http://data.datacite.org/application/pdf/10.5284/1015681. When your browser requests this URL you will be redirected to the location of the PDF specified by the owner of this DOI - Archaeology Data Service, UK.
- HTTP content negotiation lets you process a DOI’s metadata without knowledge of its origin or specifics of the registration agency.
- Data centres can provide more URLs per DOI, an end user can choose such custom URL by specifying MIME media types.