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The unAPI HTTP service interface defines three methods:

1. listFormats (e.g.: http://www.example.org/unapi/fedora)
2. listFormats for a given identifier (e.g. http://www.example.org/unapi/fedora?identifier=info:fedora/demo:1)
3. getObject for a given identifier and format (e.g. http://www.example.org/unapi/fedora?identifer=info:fedora/demo:1&format=oai_dc)

The response format for 1 & 2 is an XML document that includes the name of the format, its mime-type, and an optional description of the format. For example:

<formats id="info:fedora/demo:1">
  <format name="oai_dc" type="text/xml" docs="http://www.openarchives.org/OAI/2.0/oai_dc.xsd" />
  <format name="mods" type="applicationtext/xml" docs="http://www.loc.gov/standards/mods/v3/mods-3-2.xsd" />
</formats>

Fedora Implementation

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For the moment, I've just modified the viewObjectProfile.xslt (located in $FEDORA_HOME/server/access/) to include these two elements. As a result, the rendering of say, http://www.example.org:8080/fedora/get/demo:1http://example.org/fedora/get/demo:1, would now include those elements.

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What's called for is a programmatic means of indicating which representations of an object should be considered formats, at least as far as unAPI is concerned. A content model savvy approach might enable a dissemination that returned the unAPI formats appropriate for a given content model instance. Wiki Markup\[ diagram here\]

In my prototype, I've added an XML datastream, UNAPI-FORMATS, to a content model object. This datastream describes the disseminations that should be considered an unAPI format. Originally, I intended to describe the formats in RDF, but at least for purposes of the prototype, I'm using JSON (wrapped with <json> tags so that I could have an inline XML datastream). For example:

<json>
  [["info:fedora/*/DC","oai_dc","text/xml","http://www.openarchives.org/OAI/2.0/oai_dc.xsd"],
  ["info:fedora/*/sdef:md/get?format=mods","mods","applicationtext/xml","http://www.loc.gov/standards/mods/v3/mods-3-2.xsd"]]
</json>  

This is an array of arrays. Those familiar with the Resource Index circa Fedora 2.x might be familiar with the first (inner) array element, which we called a dissemination type. It is simply a dissemination URI where the PID of the object is replaced with a "*". The remaining elements correspond directly to the unAPI format elements. Again, this particular implementation was an expedient. A more Fedora-esque solution might employ an sDef & sDep to bind against a service that generated the JSON (or RDF) array.

The unAPI HTTP service is implemented as a separate web app. It's intended to be a general purpose service, not bound to Fedora. The Fedora-specific implementation discussed above is provided by an implementation of an ObjectResolver interface. As a proof of concept, I also implemented an OAI-PMH resolver, designed to provide unAPI services for any application that exposes OAI-PMH.

Zotero Integration

Enabling automatic citation capture in Zotero typically involves the creation of a site translator. However, translators depend on regular expression matching against a site's URL, which doesn't work for the general case of supporting any Fedora based repository. Another approach would be to embed Zotero-supported metadata in disseminations, e.g. embedding COinS in HTML renderings of Fedora objects.

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One noteworthy detail: Zotero doesn't appear to parse any other format than mods, at least when using unAPI. In my server access logs, after the request for the object (e.g. http://example.org:8080/fedora/get/demo:1), the next request is for the mods format (e.g., http://example.org:8080/unapi/fedora?id=info:fedora/demo:1&format=mods). I don't see any requests for the various formats that might be available for that resource (e.g. http://example.org:8080/unapi/fedora?id=info:fedora/demo:1). This is using Zotero 1.0.7, I haven't tried the 1.5 preview release.

Once I added mods a MODS datastream to my Fedora objects, browsing to an object's profile view yielded the little blue icon in my browser's location bar, indicating that Zotero could grok my Fedora object.

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