[Feature Request]: Support 'Internal' Targets that cannot be invoked from outside the project

[jrdodds]

Summary

Writing modular encapsulated functionality in MSBuild is sometimes difficult. A given operation may require a chain of targets where the individual targets aren't standalone and are expected to be used in concert. But all targets available on a project can be invoked on the project.

If the targets on a project are thought of being like class methods, all the methods are public.

It would be useful to have support for being able to make a target 'Internal' to a project, i.e. not public.

(If this has been proposed before, I searched and failed to find the prior issue or feature request.)

Background and Motivation

A common pattern in MSBuild is a target that defines a chain of targets and has no body, e.g.

  <Target Name="DoSomething" DependsOnTargets="_DefineSomethingProps;_PrepareSomething;_DoSomething;_FinallySomething" />

Each of the targets in the chain can have error checking and BeforeTargets, AfterTargets, and/or DependsOnTargets attributes to ensure they all run and all run in the correct order, regardless of which target is invoked.

But it may also be desirable to prevent the _DefineSomethingProps, _PrepareSomething, _DoSomething, and _FinallySomething targets from being invoked from outside the project. The DoSomething target would be the exposed public 'command'.

Proposed Feature

Introduce a new optional attribute for the Target element. The attribute might be named Internal, expect a Boolean value, and default to false when the attribute is not present. Existing code would not be impacted.

  <Target Name="_DefineSomethingProps" Internal="true" ...

When Internal is true, MSBuild will prevent the target from being invoked from outside the project.

• Passing the name of an 'internal' target via the /t switch of the command line should be an error.
• Passing the name of an 'internal' target via the Targets attribute of the MSBuild task should be an error.

Alternative Designs

No response