As background: the TransformXml MSBuild task is typically invoked in a custom build step to mark up a web.config file with per-environment configuration; its flexible directives offer highly granular control over the insertion, removal, substitution and transformation of existing configuration hierarchies. For those using the TransformXML task (typically in a Web Deployment Project) I raised an issue against Visual Studio 2010, in which the file handle on the input file was not released, meaning that following transformation the source file remained locked. As a result, the best way to transform a file was first to rename it, transform it, and then copy it back, leaving the "locked" file to be freed up later.I just heard today that this has now been resolved in Visual Studio 2012 RTM. That's good news, because Web Config Transformations offer a lot. An intelligent, automated build process will swap in the relevant transform(s), making it much easier to synthesise the Developer and Build server builds. This makes for a simpler and more exemplary build process, and with the tighter coupling comes a correspondingly quicker response to Developmental change.Oh, and don't forget -- it isn't just web.configs you can transform. You can transform app.configs, or indeed any XML file that honours the task's schema and hierarchical rules.
