AutoRunCustomTool

[!WARNING]
This project is no longer maintained. The VS extension remains available as-is on the Visual Studio marketplace, but no new version will be published.

Some of the reasons for abandoning this project are:

• It doesn't fully work with SDK-style projects (i.e. non-legacy projects), which means it's becoming irrelevant
• I no longer use this extension myself
• I switched to Rider a few years ago, and I rarely, if ever, use Visual Studio
• The main use case for this extension, T4 templates, is becoming obsolete. .NET now offers better, built-in approaches for code generation.

Feel free to fork the project if you need to make some changes.

Download from Visual Studio Marketplace: VS 2015/2017/2019, VS 2022

[!CAUTION] Known issue: This extension doesn't fully work with SDK-style (.NET Core / .NET 5+) projects. It's usable, but without UI support; you'll need to manually set the RunCustomToolOn property in the project file. See #18 for details.

A Visual Studio extension that automatically runs the custom tool on another file when a file is modified

OK, I realize that this description is perhaps not very clear, so let's take an example. Let's assume (well, it's not really an assumption; it's actually the scenario that caused me to create this tool) that in your project, you can't (or don't want to) use the default custom tool for resx resource files. Instead, you use a T4 template to generate the code associated with the resx file. So you have 3 files :

• Strings.resx, that contains the actual string resources
• Strings.tt, a T4 templates that generates code to access the resources from Strings.resx
  • Strings.cs, a C# source file that is generated by Strings.tt based on the content of Strings.resx

The problem with this setup is that Visual Studio doesn't know that a change to Strings.resx should cause a regeneration of Strings.cs, so when you just added a resource to the resx file, it's not immediately available to your code, and doesn't appear in Intellisense. You have to right-click Strings.tt and select "Run custom tool" so that the template is run again. This is very annoying...

This VS extension solves the problem very simply: when it detects a change to the "trigger" file (Strings.resx), it reruns the custom tool for the "target" file (Strings.tt).

Note that this was just an example; the trigger file doesn't have to be a resx file, and the "target" file doesn't have to be a T4 template. Both can be anything you want, as long as the target has a custom tool defined.

How to use

After you install the extension, you should see a new Run custom tool on property on each project item. Just edit this property to add the name(s) of the target file(s). That's it!

Here's a screenshot that shows how it works:

Note to users of previous versions: in previous versions, you had to set the Custom Tool property for the trigger file to "AutoRunCustomTool", and set the Custom tool namespace to the name of the target file. This sometimes caused a warning in Visual Studio : "Cannot find custom tool 'AutoRunCustomTool' on this system.". I changed the way the extension works so that it doesn't use the Custom Tool property anymore. To ensure compatibility with existing projects, the Custom Tool approach is still supported, but not recommended.