Metadata Retriever Plugins: Difference between revisions

Revision as of 14:22, 17 June 2010

Contact	Contact::Nathan Yergler
Project	,\|project_name\|Project Driver::project_name}}
Status	Status::Complete

DEd sites may wish to include metadata about Resources from other sources, including web services (ie, Semantic Analysis), databases, etc. This describes a plugin system for adding sources of information at aggregation time.

Requirements

Metadata retriever plugins are Nutch plugins which implement the MetadataRetriever extension point. MetadataRetriever extensions must implement a single method, retrieve. retrieve takes a Resource as an argument, and may add additional metadata to it. retrieve is not responsible for persisting the Resource.

We will implement two demonstration plugins: a "dummy" plugin which logs the URLs being passed to it, and a functional demonstration which uses the Delicious API to retrieve suggested and popular tags for a page.

Implementation

Added support for storing arbitrary metadata on Resource objects
Added support to TripleStore for serialization an de-serialization
Implemented the org.creativecommons.learn.plugin.MetadataRetriever extension point and org.creativecommons.learn.plugin.MetadataRetrievers extension loader
Implemented test plugins

Deferred until later

Configuration parameters for plugins (the Delicious plugin reads from discovered.xml, but the plugin.xml manifest doesn't state that it needs parameters).
Allow sequencing of MetadataRetriever plugins, to determine which are authoritative

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-Operators may wish to include metadata about Resources from other sources, including web services (ie, Semantic Analysis), databases, etc.  This describes a plugin system for adding sources of information at aggregation time.
+DEd sites may wish to include metadata about Resources from other sources, including web services (ie, Semantic Analysis), databases, etc.  This describes a plugin system for adding sources of information at aggregation time.
 == Requirements ==
-Metadata retriever plugins are Nutch plugins which implement the  MetadataRetriever extension point.  MetadataRetriever extensions must implement a single method, <code>retrieve</code>.  <code>retrieve</code> takes a Resource as an argument, and may add additional metadata to it.  <code>retrieve</code> is not responsible for persisting the Resource.
+Metadata retriever plugins are [http://wiki.apache.org/nutch/PluginCentral Nutch plugins] which implement the <code>MetadataRetriever</code> extension point.  MetadataRetriever extensions must implement a single method, <code>retrieve</code>.  <code>retrieve</code> takes a Resource as an argument, and may add additional metadata to it.  <code>retrieve</code> is not responsible for persisting the Resource.
 We will implement two demonstration plugins: a "dummy" plugin which logs the URLs being passed to it, and a functional demonstration which uses the Delicious API to [http://delicious.com/help/api#posts_suggest retrieve suggested and popular tags] for a page.