Modifying NHibernate Connection String Value from MSBUILD file.

I am a big proponent of using Team City and MSBuild to create automated deployments in to Development, Testing and Staging environments.

I recently came across a problem with modifying a standard NHibernate connection string value using MSBuild and MSBuild Extension Pack, the MSBuild Extension Pack provides a collection of over 480 MSBuild Tasks, MSBuild Loggers and MSBuild Task Factories.

A typical NHibernate configuration setting looks like the following:


The section we want to change is

<property name="connection.connection_string">Data Source=FirstSample.sdf</property>

My first attempt was to use the XPath query of

/configuration/hibernate-configuration/session-factory/property[@name='connection.connection_string']

This was not matching the app.config XML which perplexed me at first until it dawned on me to use the namespace value of "urn:nhibernate-configuration-2.2".

The XMLFile class contains a namespace node


By setting the Namespaces value in the ItemGroup and then referencing it using @(Namespaces) in the Namespaces attribute of the XMLFile class I was able to get the desired result.