A metadata editing and management system is being developed employing state of the art XML technologies. A modular and distributed design was chosen for scalability, flexibility, options for customizations, and the possibility to add more functionality at a later stage. The system consists of a desktop design tool or schema walker used to generate code for the actual online editor, a native XML database, and an online user access management application. The design tool is a Java Swing application that reads an XML schema and provides the designer with options to combine input fields into online forms and give the fields user friendly tags. Based on the design decisions the tool generates code for the online metadata editor. The code generated is an implementation of the XForms standard using the Orbeon Framework. The design tool fulfills two requirements: First, data entry forms based on one schema may be customized at design time and second data entry applications may be generated for any valid XML schema without relying on custom information in the schema. However, the customized information generated at design time is saved in a configuration file which may be re-used and changed again in the design tool. Future developments will add functionality to the design tool to integrate help text, tool tips, project specific keyword lists, and thesaurus services.
Additional styling of the finished editor is accomplished via cascading style sheets which may be further customized and different look-and-feels may be accumulated through the community process.
The customized editor produces XML files in compliance with the original schema, however, files are saved into a native XML database whenever the user moves to the next screen or pushes the save button independently of validity. Currently the system uses the open source XML database eXist for storage and management, which comes with third party online and desktop management tools. However, access to metadata files in the application introduced here is managed in a custom online module, using a MySQL backend accessed by a simple Java Server Faces front end. A flexible system with three grouping options, organization, group and single editing access are provided. Three levels were chosen to distribute administrative responsibilities and handle the common situation of an information manager entering the bulk of the metadata but leave specifics to the actual data provider.
The project is developed under the open source license and access to code and documentation is provided at http://intranet.lternet.edu/im/project/MetadataEditor .