How to add config transformations for a custom config file in Visual Studio?

Question

The project I am working on involves reading a lot of service endpoints (url) from a config file. Since the list would be quite large I decided to keep them in a custom conf

Answer 1

Since the OP asked about Web.config transformations during the deployment lets assume a WPP is already in there. So I've hacked on the WPP.

I use the following snippet to transform Umbraco's own config files (but indeed any configs suit well):

  
    
      Config\umbracoSettings.config
    
  

  
    
      $(CollectWebConfigsToTransformDependsOn);
      CollectUmbracoConfigsToTransform
    
  

  
    
    
      
        false
        $([System.String]::new($(WebPublishPipelineProjectDirectory)\$([System.IO.Path]::GetDirectoryName($([System.String]::new(%(DestinationRelativePath)))))).TrimEnd('\'))\%(Filename).$(Configuration)%(Extension)
        $(TransformWebConfigIntermediateLocation)\original
        $(TransformWebConfigIntermediateLocation)\assist
        $(TransformWebConfigIntermediateLocation)\transformed\%(DestinationRelativePath)
        $([System.IO.Path]::GetFullPath($(WPPAllFilesInSingleFolder)\%(DestinationRelativePath)))
      
    
  

I name it Umbraco.wpp.targets and drop inside project's root. The the WPP automatically imports it.

All you have then to do is add a transform file (Config\umbracoSettings.Release.config is case of this sample).