VSX: ProjectFlavor-only item VSTemplates?

Question

In Visual Studio 2005, 2008, and 2010, is it possible to define an Item Template that only appears in the Add Item dialog for projects of a particular ProjectFlavor? I'd rather not clutter all of the other unrelated projects' Add Items dialog if I can help it.

Seems that the <ProjectType>CSharp</ProjectType> is a fixed enumeration and I can't find any place for a ProjectFlavor guid or otherwise.

I don't see any examples of other products showing such restraint, but I want to make sure.

=====

OK, Aaron's tip is very promising but my first attempt is unsuccessful.

In the .vstemplate:

<TemplateData>
    <Name>MyProject A File</Name>
    <Description>MyProject A File to do stuff</Description>
    <Icon>A.ico</Icon>
    <TemplateID>TemplateID_A</TemplateID>
    <TemplateGroupID>MyTemplateGroupID</TemplateGroupID>
    <ProjectType>CSharp</ProjectType>
    <RequiredFrameworkVersion>2.0</RequiredFrameworkVersion>
    <SortOrder>20</SortOrder>
    <NumberOfParentCategoriesToRollUp>1</NumberOfParentCategoriesToRollUp>
    <DefaultName>Template_A.cs</DefaultName>
    <ProvideDefaultName>true</ProvideDefaultName>
    <ShowByDefault>false</ShowByDefault>
</TemplateData>
<TemplateContent>
    <ProjectItem ReplaceParameters="true">Template_A.cs</ProjectItem>
</TemplateContent>

And on the package.cs:

// [ProvideProjectItem(typeof(MyProjectFactory), "MyTemplateGroupID", 
//    @"Templates\ProjectItems", 600)] // Took this out.

[ProvideProjectFactory(typeof(MyProjectFactory), 
    "My Project", "My Project Files (*.csproj);*.csproj", 
    null, null, @"Templates\Projects", 
    LanguageVsTemplate = "CSharp", 
    NewProjectRequireNewFolderVsTemplate = true, 
    TemplateGroupIDsVsTemplate="MyTemplateGroupID",
    TemplateIDsVsTemplate = "TemplateID_A,TemplateID_B")]
public sealed class MyPackage : Package { ... }

Answer 1

Yes this is possible and there are a few item templates "in the box" that do this. For example, you'll notice that the C# or VB item templates for WPF items (Page, Window, FlowDocument, etc...) only appear if you're working with a WPF-flavored project.

The trick is to specify the same TemplateGroupID in each vstemplate file, and then specify this same TemplateGroupID in the registration of your project flavor.