Just-in-Time Itemization
By Sandra Schloen, March 2019
This strategy supports the use of existing feature tables in a compatible geodatabase format or the use of the attribute table of a shapefile to supplement OCHRE data as reference material. OCHRE will itemize the unique values of a chosen table field on demand, making those items’ geometries (points, lines or polygons) available to be used in conjunction with other project data in the Map Viewer. For example, the paleo-environment component of the CRANE project uses data files provided by the Soil and Water Assessment Tool (SWAT) for the purpose of visualization, complementing the data collected by the project.
When using this strategy, the source geodatabase or shapefiles are added to the project as Resource items in the usual way then linked to a Set or a Hierarchy to enable the exposure of their contained items for use in illustrated Views as needed. One of the fields of a selected table in the geodatabase, or a field of the shapefile’s attribute table, must be specified as the table column within which OCHRE can expect to find a discrete list of values. On demand, OCHRE can fetch the items and shapes from the specified field and display their shapes as needed.
Items created and fetched on-the-fly for a View using this approach are transient, not leaving a trace once the View has been closed. This strategy is generally used for illustrative purposes. Shown below is a shapefile identifying vegetation zones in central Turkey. The user has access to the list of items in the attribute table of the shapefile and can toggle the items on/off, here showing only the cedars of Lebanon and juniper trees.
