Describing and Verifying Integrity Constraints in XML Using OCL

Today, information systems rely largely on web services and XML as their payloads. Every information system also depends on checking and preserving integrity constraints. In the world of conceptual modeling, they can be expressed using Object Constraint Language (OCL) expressions over class diagrams. However, the expressions defined in the conceptual model of the system must be rewritten to the form of XML schemas to be used for XML and web services. This is an error-prone task for a system designer who, in addition, must be skilled both in OCL and XPath and other XML languages. In this work, we show how OCL integrity constraints can be translated to Schematron schemas automatically and verified in XML documents thus reducing the effort of the initial translation and maintenance.