Problem statement

The solution

Joda seeks to provide a single model for all these technologies to work around, effectively next generation JavaBeans. The data in the model can be viewed and manipulated using a JavaBean style interfaces. But it can also be viewed and manipulated using a DOM style API. These two programming styles are effectively just two views on the same data and are continuously in sync. And there is no XML style restriction of a hierarchical view of the model.

This dual interface into the program enables many other technologies to be linked to a Joda model easily. For example:

• XML input/output - The entire model can be written to or from XML using a default XML style
• XPath querying - The object model can be queried using XPath, from Jaxen.org
• DOM view - The property model can be accessed using the raw DOM API
• Swing bindings - A property can be linked to a Swing GUI so changes to one update the other and vice versa
• Model views - The same object model could be viewed in a transformed structure, in sync, continuously updated
• Error handing - Errors messages can be attached to an individual property
• JDBC binding - A simple, or complex, binding to JDBC data could be developed
• XML database binding - A binding to and from an XML database, such as Apache Xindice, could be developed
• Compare two models - Two given object model trees can be examined for differences, such as to only save changes to a database
• Network traffic optimisation - By comparing two models, only data that has to be sent accross a network has to be sent

Each of the functions above will be developed as separate modules operating on the core Joda property model. Ideally, some will become separate open-source projects, for example the Swing and Database bindings.

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