Tools for previewing configuration file transformations

Question

Are there any tools or Visual Studio 2010 extensions which allow me to view the output of a configuration file transformation short of having to publish the entire project? Is the process which performs the transformation directly invokable?

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Edit

After a little more Googling I came across this:

Step 4: Generating a new transformed web.config file for “Staging” environment from command line

Open Visual Studio Command prompt by going to Start --> Program Files –> Visual Studio v10.0 –> Visual Studio tools –> Visual Studio 10.0 Command Prompt

Type “MSBuild “Path to Application project file (.csproj/.vbproj) ” /t:TransformWebConfig /p:Configuration=Staging" and hit enter as shown below:

Once the transformation is successful the web.config for the “Staging” configuration will be stored under obj -->Staging folder under your project root (In solution explorer you can access this folder by first un-hiding the hidden files) :

• In the solution explorer click the button to show hidden files
• Open the Obj folder
• Navigate to your Active configuration (in our current case it is “Staging”)
• You can find the transformed web.config there

You can now verify that the new staging web.config file generated has the changed connection string section.

Source: Web Deployment: Web.Config Transformation

This isn't really a perfect solution for me as it still requires building the entire project- at least with the command he posted. If anyone knows of way to skip the build step with the MSBuild command that would be helpful (although that sounds somewhat unlikely).

Edit 2

I also found this Config Transformation Tool on CodePlex, which offers some nice functionality to extend the transformation process. This is tool is the closest thing I've seen for the functionality I'm seeking and would be a great starting point for developing an extension which creates previews. It uses the Microsoft.Web.Publishing.Tasks library to perform the transformation and does not depend on building an actual project.

Answer 1

The SlowCheetah VS add-in on the visualstudiogallery allows you to preview the transform results

Answer 2

You can transform a config file by using the same objects the MSBuild task uses, bypassing MSBuild altogether. Web config transform logic is contained in the Microsoft.Web.Publishing.Tasks library.

The following code snippet comes from a simple class library, referencing the Microsoft.Web.Publishing.Tasks library (which is installed on my machine at C:\Program Files (x86)\MSBuild\Microsoft\VisualStudio\v10.0\Web).

The sample loads a source document and transform, applies the transform, and writes the results to a new file.

using System;
using Microsoft.Web.Publishing.Tasks;

// ...

var xmlTarget = new XmlTransformableDocument();
xmlTarget.PreserveWhitespace = true;
xmlTarget.Load("Web.config");

var xmlTransform = new XmlTransformation("Web.Release.config");

if (xmlTransform.Apply(xmlTarget))
    xmlTarget.Save("Web.Transformed.config");
else
    Console.WriteLine("Unable to apply transform.");

With a little creativity, this simple solution could be integrated into a Visual Studio plugin, perhaps as a context menu item on the web.config file. At the very least, you can make a console utility or script out of it to generate previews.

Good luck!