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MetadataWebService Task

DSpace metadata (typically item metadata ) can contain any number of identifiers or other field values that participate in networked information systems. For example, an item may include a DOI which is a controlled identifier in the DOI registry. Many web services exist to leverage these values, by using them as 'keys' to retrieve other useful data. In the DOI case for example, CrossRef provides many services that given a DOI will return author lists, citations, etc. The MetadataWebService task enables the use of such services, and allows you to obtain and (optionally) add to DSpace metadata the results of any web service call to any service provider. You simply need to describe what service you want to call, and what to do with the results. Using the task code, you can create as many distinct tasks as you have services you want to call. Each description lives in a configuration file in 'config/modules', and is a simple properties file, like all other DSpace configuration files. The name of the configuration file is the task name you assign to it in config/modules/curate.cfg. There are a few required properties you must configure for any service, and for certain services, a few additional ones. An example will illustrate best.

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Suppose items (holding journal articles) include 'dc.identifier.issn' when available. We might also want to catalog the publisher name (in 'dc.publisher'). The cataloger could look up the name given the ISSN in various sources, but this 'research' is tedious, costly and error-prone. There are many good quality, free web services that can furnish this information. So we will configure a MetadataWebService task to call a service, and then automatically assign the publisher name to the item metadata. As noted above, all that is needed is a description of the service, and what to do with the results. Create a new file in 'config/modules' called 'issn2pubname.cfg' (or whatever is mnemonically useful to you). The first property in this file describes the service as a 'template'. The template is just the URL to call the web service, with parameters to substitute values in. Here we will use the 'Sherpa/Romeo' service:

template=http://www.sherpa.ac.uk/romeo/api29.php?issn={dc.identifier.issn}

When the task runs, it will replace '{dc.idnetifieridentifier.issn}' with the value of that field in the item, If the field has multiple values, the first one will be used. As a web service, the call to the above URL will return an XML document containing information (including the publisher name) about that ISSN. We need to describe what to do with this response document, i.e. what elements we want to extract, and what to do with the extracted content. This description is encoded in a property called the 'datamap'. Using the example service above we might have:

datamap=//publisher/name=>dc.publisher,//romeocolor

Each separate instruction is separated by a comma, so there are 2 instructions in this map. The first instruction essentially says: find the XML element 'publisher name' and assign the value or values of this element to the 'dc.publisher' field of the item. The second instruction says: find the XML element 'romeocolor', but do not add it to the DSpace item metadata - simply add it to the task result string (so that it can be seen by the person running the task).

NoOp Curation Task

This task does absolutely nothing. It is intended as a starting point for developers and administrators wishing to learn more about the curation system.

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