DataSHIELD Interface (DSI) implementation for Opal data warehouse, based on Opal R Client (opalr) package.

This is the reference implementation of the DataSHIELD Interface that can be used for implementing other data repository clients supporting DataSHIELD infrastructure.

See usage examples.

Articles about Opal and DataSHIELD: * DataSHIELD – New Directions and Dimensions * DataSHIELD: taking the analysis to the data, not the data to the analysis * Software Application Profile: Opal and Mica: open-source software solutions for epidemiological data management, harmonization and dissemination