Limbo.Umbraco.MultiNodeTreePicker adds a special multinode treepicker to the Umbraco backoffice in which developers can select a custom item converter.

The purpose of an item converter is to control the C# type returned by the .Value() method or the corresponding property in a ModelsBuilder generated model. This is particular useful in a SPA/Headless Umbraco implementation, where the ModelsBuilder model can then be returned directly via a WebAPI endpoint.

The package targets Umbraco 10 and is only available via NuGet. To install the package, you can use either .NET CLI

dotnet add package Limbo.Umbraco.MultiNodeTreePicker --version 1.0.6

or the NuGet Package Manager:

Install-Package Limbo.Umbraco.MultiNodeTreePicker -Version 1.0.6

Note
This package replaces our older Skybrud.Umbraco.MultiNodeTreePicker package. See this package for older versions of Umbraco.

At @limbo-works we typically use Umbraco as a headless CMS, and being able to control the generated models therefore makes a lot of sense. If a given page has some related content, it doesn't make sense for us to return the full model of a related model, so we instead have an item class with the needed properties - this class could be called TestItem.

Normally the property with the related content would return the full model for each page, but with the special multinode treepicker from this package, we can implement a custom item converter.

We can do this by implementing the IMntpItemConverter interface, but to get going a bit quicker, the package also contains the abstract MntpGenericItemConverter class we can use instead:

public class TestMntpItemConverter : MntpGenericItemConverter<TestItem> {

    public TestMntpItemConverter() : base("Default item converter", x => new TestItem(x)) { }

}

public class TestItem {
        
        public Guid Key { get; }

        public string Name { get; }

        public string Url { get; }
        
        public TestItem(IPublishedContent content) {
            Key = content.Key;
            Name = content.Name;
            Url = content.Url;
        }

    }

The MntpGenericItemConverter class requires us to specify a name for the converter, and then a callback function that will be used for converting each IPublishedContent to the desired type.

When the data type is configured to use our item converter (see screenshot above), properties of this type will now return List<TestItem> instead of List<IPublishedContent>.

With this special multinode treepicker, it's the datatype of the individual property, that determines the returned value. Another property could for instance be for selecting contact persons where we'd need a bit more information than what's available from the TestItem class, so we can create another item converter:

  public class TestMntpPersonItemConverter : MntpGenericItemConverter<TestPersonItem> {

      public TestMntpPersonItemConverter() : base("Person item converter", x => new TestPersonItem(x)) { }

  }

  public class TestPersonItem : TestItem {

      public string Phone { get; }

      public string Email { get; }

      public TestPersonItem(IPublishedContent content) : base(content) {
          Phone = content.Value<string>("phone");
          Email = content.Value<string>("email");
      }

  }

• See more at packages.limbo.works

The item converters in this package was inspired by a similar concept in the Contentment package. Thanks for creating and sharing this with us @leekelleher 👍