OAI-PMH Provider

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[Available for v1.4]

CollectiveAccess features an implementation of the OAI Protocol for Metadata Harvesting that serves database records using virtually arbitrary XML-based formats. It supports all requests defined in the protocol and is made possible through the Data_Exporter framework.

In order to make your data available via OAI-PMH you first have to create at least one XML mapping for the data exporter. Data providers are required to provide at least Dublin Core so we suggest you start with that. You can, however, provide any number of formats so long as you create the corresponding export mappings in CollectiveAccess.

For now we assume that you created a mapping with the code 'oai_dc' that describes how your data is mapped to Dublin Core XML.

oai_provider.conf Configuration

This is the core configuration file for this feature. If you want to provide only one the Dublin Core mapping you just created, you're pretty much good to go with the stock configuration. Just fill in the mapping code. The interesting part of the configuration is under the 'providers' key. Here you can define an arbitrary number of endpoints where harvesters can go and gather your data. You could, for instance, define 1 endpoint for your object/item records and one for your collections. Each of those is a full-fledged standalone OAI-PMH provider accessible via the following URL pattern:

http://www.mydomain.org/service.php/OAI/<provider_key>

In the default config there's only one provider with the code 'dc'. It can be accessed like so:

http://www.mydomain.org/service.php/OAI/dc

Within each provider configuration you have a number of available settings. They are described in the table below.

Setting Description Example value
name Used as repositoryName for the response to the Identify verb. By default it is imported from your setup.php. My repository
admin_email Used as adminEmail for the response to the Identify verb. By default it is imported from your setup.php me@mydomain.org
setFacet A browse.conf facet code used to divide the data set you're providing into so called 'sets' (OAI terminology, not necessarily equivalent to CollectiveAccess sets) and build the response to the ListSets verb. By default associated collections are used. collection_facet
query Search query that allows you to impose arbitrary restrictions on the record set that is being provided. By default all records ('*') are served. ca_objects.idno:0001*
formats List of the metadata formats that are available for this provider. Further information on the format definition is below. see below
default_format Code of the format to use if the metadataPrefix argument is omitted, i.e. if the harvester doesn't specify which format he wants. You should almost always serve basic Dublin Core in those cases. oai_dc
identiferNamespace Namespace to use to build globally unique identifiers from your local CollectiveAccess record ids. The identifiers look like this: oai:<namespace>:<localID> whirl-i-gig.com
dont_enforce_access_settings if set, no access checks are performed 0
public_access_settings list of values for 'access' field in objects, entities, places, etc. that allow public (unrestricted) viewing [1]
privileged_access_settings list of values for 'access' field in objects, entities, places, etc. that allow privileged viewing (ie. user in on a privileged network as defined below) [1,2]
privileged_networks List of IP address to consider "privileged" (can see items where access = 1 or 2) It is ok to use wildcards ("*") for portions of the address to create class C or B addresses, e.g. 192.168.1.5, 192.168.1.* and 192.168.*.* are all valid and increasingly broad [192.168.6.*]
dont_cache Determines if search or browse results used to built responses are cached or not 1
show_deleted Determines if deleted records are included in list responses 0

Format Definition

The definition of a single format used by a provider configures the exporter mapping that should be used for this format as well as some metadata about the format itself. The type of records served (objects, entities, ...) is defined by the exporter mapping. We strongly recommend not to mix mappings for different types in one provider. If you want to provide, say, your objects and your collections, you should configure 2 separate providers to do this, otherwise harvesters could get inconsistent results for the same identifiers.

The key of the format definition is the so called metadataPrefix. It is used to address these formats in OAI-PMH requests (and also for the 'default_format' setting).

Setting Description Example value
mapping Code of the exporter mapping to use for this provided format oai_dc
schema Used only to describe this format for the ListMetadataFormats verb. If you want schema definitions to appear in the protocol responses, they should be part of your export mapping. http://www.openarchives.org/OAI/2.0/oai_dc.xsd
metadataNamespace Used only to describe this format for the ListMetadataFormats verb. If you want namespace definitions to appear in the responses, they should be part of your export mapping. http://www.openarchives.org/OAI/2.0/oai_dc/

An example configuration with only one format (metadataPrefix: oai_dc) served by the provider could look like this:

formats = {
	oai_dc = {
		mapping = ca_objects_oai_dc,
		schema = http://www.openarchives.org/OAI/2.0/oai_dc.xsd,
		metadataNamespace = http://www.openarchives.org/OAI/2.0/oai_dc/,
	}
},

Testing your setup

To explore your collection using the OAI-PMH provider you just set up, you can for instance use the OAI Repository Explorer maintained by the University of Cape Town. This tool obviously only works if your provider is accessible online.

DPLA

Partner hubs of the Digital Public Library of America can provide metadata to the DPLA by setting up an OAI-PMH provider servicing data in either DublinCore, MARC, or MODS. Consult with the DPLA for other supported formats, or refer to the DPLA metadata specification crosswalk here.

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