4   Implementation

Only a modest amount of development work was necessary to extend Greenstone to support the notion of generalized institutional repository given earlier. The three enabling technologies were macros, runtime actions, and incremental building, all of which exist in Greenstone.

Greenstone macros are the key to controlling the generalized workflow. Checking form content and manipulations of form layout (adding in previous values etc.) are spliced into macros through JavaScript and DOM manipulation. To enable document submission, an existing runtime 'action' called The Collector [5], which supports the creation and building of collections through a web browser, was further abstracted and generalized. This 'action' was already able to provide a progress bar and used a database to store previously entered values from one page to the next. The new extension was to add support for multipart form file-upload with the new action called “the depositor.” Incremental building using the Lucene indexer [6] is already a feature of Greenstone.