Access digital objects!
The Royal Library, Copenhagen, has been digitizing Cultural Heritage Objects in its collections since well over two decades. More recently, the last 8-10 years, we have tried to build our dissemination platforms using a REST based architecture.
This collection of documents describes the various APIs we are using ourselves to provide access to our data to library patrons, in the hope that the access points could be useful for a new category library patron whose research or studies would benefit from programmatic access to our digital collections.
Licences & Legalese
The documention here is provided as is, and mind you: Everything that's free comes with no guarantee. As a matter of fact the material in this git repository is licensed to you as GNU Free Documentation License
The material we provide access to using the APIs described are of two kinds:
Metadata: This comes to you as CC0 1.0 Universal. I.e., our metadata is basically public domain.
Content: The content in our digital collections are delivered with varous licenses, but the most common one is Attribution-NonCommercial-NoDerivs 2.0 Generic. I.e., our content is provided with a much more restrictive CC license.
The APIs described have been used successfully in projects (in some cases for many years). We, their users & developers, created each of them for getting a job done. They are usually well tested and works well, but they are neither polished, nor are there helpful error messages etc.
The formats we are delivering are to a large extent based on standards. That means that in many places we refer to external documentation whenever possible. We are not guaranteeing anything concerning the external information sources, nor that our data are strictly valid in relation to those documents.
Services by scope and purpose
Our services builds upon the ideas
as they are presented by Tim Berners-Lee. We don't promise that our links will persist for 2000 years, but we do our best to keep them and if we don't we promise to make redirects according to best practise.
As you will see, we are slightly better than three on Berners-Lee's five grade scale. We do not provide access to RDF and SPARQL but RSS and OpenSearch. Few provide access to RDF these days, so perhaps W3C should redesign the cop (see above).
Neither do we link to external sources.
A brief introduction to the characters in the story
- Digital Editions - COP, an acronym for which one possible interpretation could be Common Object Publishing platform. The word Common would refer to that it is a platform which is common between different collections and media types. However, when it was released we intentionally never gave the service a brand name.
- Aerial Photography collection - DSFL (Danmark Set Fra Luften)
- Rex - our Integrated Library System and Aleph - our Online public access catalog (OPAC)
- National Aggregator - A system run by us aggregating material from Danish libraries, museums and archives on behalf of Europeana
- Archive for Danish Literature, ADL
Dissemination of metadata
The purpose of our dissemination is to enable us to synchronize data between our own systems, but also to share our data with Cultural Heritage communities at large. The dissemination services are aimed as aggregator services of various kinds. Our dissemination API is OAI-PMH
Search and retrieval
The metadata and objects in COP are accessible from two front ends
Both services use the same web service, but DFSL has some geographical extensions in order to run its map based interface
Through COP we deliver metadata to various services, in different formats.
Virtually all content in COP is delivered as images; delivery is described in a separate document.
Text and literature
Currently the whole Archive for Danish Literature is available.
Andreas Borchsenius West contributed information about feeds and the JSON service used for maps, notably our Aerial photography collection Danmark Set Fra Luften (DSFL).