Best Practices - Updating XML Application

[scnetworks]

Am working with a developer who has created an XML based stand alone Java application. End users will input much data in to this application for their personal use.

The application will be upgraded, and development continued over time.

We are at a point in trying to find the best way to push updates, which very well will (they will) have schema changes. We need to preserve all of the data the end user has inputted in to their current session and have the update be as "transparent" to the end user, if not completely as possible.

As owner of the application, I'm both trying to learn and help provide the developer find the best way to do this.

I would like to ask the community for their suggestions and recommendations.

Thank you in advance.

[Tolls]

Versioned schemas.
Transform the xml from one version to another.

Something along those lines.

Obviously I have no idea what your actual system looks like, so this maybe rubbish.