Web Config Transforms: Insert If Not Exists

Question

I would like to apply a transformation if and only if a matched element does not exist in the target. Trying various xpath expressions using http://webconfigtransformationtester.apphb.com/ but no luck so far.

E.g. if the target web.config looks like this:

<configuration>   <system.web>     <compilation debug="true" />   </system.web> </configuration> 

then the output should look like this:

<configuration>   <connectionStrings>     <add name="MyCs" provider="System.Data.SqlClient" connectionString="" />     <add name="SomeOtherCs" provider="System.Data.SqlClient" connectionString="" />   </connectionStrings>   <system.web>     <compilation debug="true" />   </system.web> </configuration> 

But if the target looks like this:

<configuration>   <connectionStrings>     <add name="MyCs" provider="System.Data.IChangedIt" connectionString="my connection string here" />   </connectionStrings>   <system.web>     <compilation debug="true" />   </system.web> </configuration> 

then the result of the transformation should look like this:

<configuration>   <connectionStrings>     <add name="MyCs" provider="System.Data.IChangedIt" connectionString="my connection string here" />     <add name="SomeOtherCs" provider="System.Data.SqlClient" connectionString="" />      </connectionStrings>   <system.web>     <compilation debug="true" />   </system.web> </configuration> 

In other words, I just want to add the named connection string to configuration but let the administrator fill it in with his own values. I thought it would as simple as xdt:Transform="Insert" xdt:Locator="XPath(count(/configuration/connectionStrings)=0)" (to add a cs config section if none existed) but apparently not.

Answer 1

Use xdt:Transform="InsertIfMissing" with the XmlTransform task in VS2012. It doesn't look like Microsoft has updated their documentation to reflect this yet.

Answer 2

In my case xdt:Transform="InsertIfMissing" did not work without xdt:Locator="Match(name)"