Create a Menu Extension

Introduction

This how-to describes how you can create an extension that adds an item to Studio Pro menu from scratch.

You can download the example in this how-to in this GitHub repository.

Creating an Extension Project

1. Create a new project in Visual Studio based on C# Class Library template.

2. Choose a name for the project. Use a format similar to MyCompany.MyProject.MendixExtension, but it is not a hard requirement.

3. Choose .NET 8.0 Framework.

4. Add Mendix.StudioPro.ExtensionsAPI NuGet package to the project references. Pick the version that does not exceed the Studio Pro version you installed. To do so, perform the following steps:

   1. Include a reference to the Extensions API NuGet package:

   2. Add new file named manifest.json to your project. Put the following content into it:

      { "mx_extensions": [ "<name_of_your_project>.dll" ] }
      

   3. For the manifest.json file, right-click Solution Explorer > Properties and change the Copy to Output Directory property to Copy always.

Creating a Test Mendix App

It is handy to have an app where the extension is used for the testing purposes. Perhaps you even want to share this app with your team by committing its code next to the extension project.

1. Create a new Mendix app to use for testing the extension, based on a starter app of your choice. You can also use an existing app.
2. Go to App > Show App Directory in Explorer to open the app directory.
3. Create a new folder extensions inside the app directory.
4. Create a subfolder named after your extension, for example, MyCompany, inside the extensions folder.
5. Copy the full path of the subfolder by pressing Shift and right-clicking at the same time, and then selecting Copy as path.
6. Add the Post-build event script below to your extension project Build > Events configuration: xcopy /y /s /i "$(TargetDir)" "<path_to_folder>"

Now if you build your extension project (usually you can do this by pressing Ctrl + Shift + B) and click Synchronize App Directory in Studio Pro (or press F4), the latest version of your extension will be loaded.

Creating Your First Extension

To introduce a simple extension that adds a menu item to Studio Pro, add the following class:

using System.ComponentModel.Composition;
using Mendix.StudioPro.ExtensionsAPI.UI.Menu;
using Mendix.StudioPro.ExtensionsAPI.UI.Services;

namespace MyCompany.MyProject.MendixExtension;

[method: ImportingConstructor]
[Export(typeof(MenuExtension))]
public class MyMenuExtension(IMessageBoxService messageBoxService) : MenuExtension
{
    public override IEnumerable<MenuViewModel> GetMenus()
    {
        yield return new MenuViewModel("Say hello", () => messageBoxService.ShowInformation("Hello World!"));
    }
}

Build your extension and press F4 in Studio Pro. Extension menu items are placed under a corresponding menu with the extensions name. If your extension is named “My Extension”, then your menu items will be located under the Extensions > My Company submenu.

The Extensibility API provides you with several services you can use and they are injected into your extension classes by using the ImportingConstructor attribute.

It is also possible to get notified when your extension has been successfully loaded into Studio Pro and also just before it gets unloaded. It is as simple as subscribing to the ExtensionLoaded and ExtensionUnloading events.

using Mendix.StudioPro.ExtensionsAPI.UI.Events;

namespace MyCompany.MyProject.MendixExtension;

[method: ImportingConstructor]
[Export(typeof(MenuExtension))]
public class MyMenuExtension() : MenuExtension
{
    public MyMenuExtension()
    {
       Subscribe<ExtensionLoaded>(onEvent: () => { MyActionOnLoaded() });
       Subscribe<ExtensionUnloading>(onEvent: () => { MyActionOnUnloading() });
    }
}

Debugging Your Extension

1. Make sure that the current version of the extension code is loaded in Studio Pro.

2. Attach to Studio Pro process in Visual Studio debugger as follows:

   1. On the Debug menu, open the Attach to Process dialog box (or press Ctrl + Alt + P).
   2. Search for studiopro.exe among the processes.
   3. Select the only found process (or the one with correct title, if you have many) and select Attach.

3. Add a Breakpoint inside Action delegate in MyMenuExtension.GetMenus(). It will be hit when you click Extensions > MyCompany > Say hello menu item.

Adding a NuGet Dependency

You can freely use NuGet packages from extensions to access reusable .NET libraries. The following one-time additional setup is required:

1. Open your extension project .csproj file by right-clicking Solution Explorer > Edit Project File.

2. Add the following line into the first <PropertyGroup>:

       <CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>
   

Then you can add a NuGet dependency, for example, using the Manage NuGet Packages menu.