How to output namespace in T4 templates?

Question

I have a T4 template for a class set up with TextTemplatingFileGenerator Custom Tool in Visual Studio:

<#@ template language="C#v3.5" hostspecific="True" debug="True" #>
<#
  var className = System.IO.Path.GetFileNameWithoutExtension(Host.TemplateFile);
  var namespaceName = "MyNamespace";
#>

namespace <#= namespaceName #>
{
    public static class <#= className #>
    {
        // some generated code
    }
}

How can I get the value of the "Custom Tool Namespace" property in Visual Studio, so I don't have to hardcode the namespace?

I would even be happy with the default namespace for the C# project.

Miniver

Answer 1

If you're using Visual Studio 2010, you can retrieve the namespace by checking the CallContext's "NamespaceHint" property.

System.Runtime.Remoting.Messaging.CallContext.LogicalGetData("NamespaceHint");

Foursome

Unfortunately, this trick doesn't work when using the MSBuild-based transformation system (as illustrated here: olegsych.com/2010/04/understanding-t4-msbuild-integration). Bummer. :( – Concession

This function makes debugging fail – Majolica

@BradWilson The link seems to be broken. – Homerhomere

@venkat Not sure what you're asking of Brad from a seven year old comment. – Foursome

@GarethJ - The link (http://www.olegsych.com/2010/04/understanding-t4-msbuild-integration/) mentioned in @BradWilson comment seems to be not working and requesting for alternative links if any exists. – Homerhomere

@Venkat, At this point, I think as a community member, you are as capable of using a search engine and providing any more up to date information that's available as the rest of us. – Foursome

The article mentioned by Brad can be visualized here : web.archive.org/web/20130805044018/http://www.olegsych.com:80/… – Quadrireme

Answer 2

Here is what you can do with T4 Toolbox:

<#@ template language="C#v3.5" hostspecific="True" debug="True" #> 
<#@ include file="T4Toolbox.tt" #>
<# 
  var namespaceName = TransformationContext.DefaultNamespace; 
#> 

DefaultNamespace property of TransformationContext class returns a string with namespace based on the root namespace of your project and the location of your .tt file in it (i.e. it treats folders as namespaces). This way you don't have to specify Custom Tool Namespace property for every instance of your .tt file.

If you prefer to use the Custom Tool Namespace property, you can pass Host.TemplateFile to the GetCustomToolNamespace method posted by @sixlettervariables.

Edholm

I get the error: 'T4Toolbox.TransformationContext' does not contain a definition for 'DefaultNamespace' – Symons

Found a fix in this post of yours: olegsych.com/2012/12/t4-toolbox-for-visual-studio-2012 – Symons

That post is now gone, but the DefaultNamespace appears to now be in the T4Toolbox.ClrTemplate class. (Although the whole project needs updating for VS 2019) – Howlyn

Answer 3

Damien Guard includes some code in a blog posting which retrieves the Custom Tool Namespace for a given file:

public override String GetCustomToolNamespace(string fileName)
{
    return dte.Solution.FindProjectItem(fileName).Properties.Item("CustomToolNamespace").Value.ToString();
}

Chessman

Answer 4

How I've done this:

<#@ assembly name="EnvDTE" #>
<#@ import namespace="EnvDTE" #>

<# 
    // Get value of 'Custom Tool Namespace'
    var serviceProvider = (IServiceProvider)this.Host;
    var dte = (DTE)serviceProvider.GetService(typeof(DTE));    
    var Namespace = dte.Solution.FindProjectItem(this.Host.TemplateFile).Properties.Item("CustomToolNamespace").Value;
 #>

namespace <#= Namespace #> {

}

Considering

worked for me; replaced "CustomToolNamespace" with "DefaultNamespace" – Tradescantia

Answer 5

If you use Visual Studio 2012

EdmItemCollection ItemCollection = loader.CreateEdmItemCollection(inputFile);
string namespaceName = System.Runtime.Remoting.Messaging.CallContext.LogicalGetData("NamespaceHint").ToString();

EntityFrameworkTemplateFileManager fileManager = EntityFrameworkTemplateFileManager.Create(this);

Aldo Flores @alduar

Derby

Answer 6

The accepted answer doesn't work on Visual Basic Projects. I had to use the method from: http://lennybacon.com/post/2010/12/10/generatingcodefileswithcorrectnamespacesusingt4

var hostServiceProvider = (IServiceProvider)Host;
var dte = (EnvDTE.DTE)hostServiceProvider.GetService(typeof(EnvDTE.DTE));
var activeSolutionProjects = (Array)dte.ActiveSolutionProjects;
var dteProject = (EnvDTE.Project)activeSolutionProjects.GetValue(0);
var defaultNamespace = dteProject.Properties.Item("DefaultNamespace").Value;

Sybilla