Item Converters

The package introduces a concept called item converters, which essentially is about converting the default multinode treepicker return values into something else.

For instance, if you have a picker on a page for selecting related pages, you most likely don't need the IPublishedContent, but rather some limited information about each selected page (or item if you will).

When you have created a new MNTP data type, you can select an item converter. Currently the package only ships with a single item converter, but by implementing the IMntpItemConverter interface, you can create your own custom item converter.

You can select the item converter via the options on the multinode treepicker data type.

In the example below, the item converter converts the selected IPublishedContent into instances of MyContentItem. As also show in this example, your custom item converters can use dependency injection - e.g. for delegating the work of creating the item to an item factory.

When implementing the IMntpItemConverter interface, the Convert method is responsible for convert each IPublishedContent to the desired value, whereas the GetType is used for indication a common type for each item.

using System;
using MntpDemo.Factories;
using MntpDemo.Models.Common;
using Limbo.Umbraco.MultiNodeTreePicker.Converters;
using Umbraco.Cms.Core.Models.PublishedContent;

namespace MntpDemo.Converters;

public class MyContentItemConverter : IMntpItemConverter {

    private readonly MyItemFactory _itemFactory;

    #region Properties

    public string Name => "My Content Item Converter";

    public string Icon => "icon-box-open";

    #endregion

    #region Constructors

    public CitiContentItemConverter(MyItemFactory itemFactory) {
        _itemFactory = itemFactory;
    }

    #endregion

    #region Member methods

    public object? Convert(IPublishedPropertyType propertyType, IPublishedContent? source) {
        return source is null ? null : _itemFactory.CreateContentItem(source);
    }

    public Type GetType(IPublishedPropertyType propertyType) {
        return typeof(MyContentItem);
    }

    #endregion

}

Under the hood, the package will automatically detect whether the data type is configured as a multi picker or a single picker, which you don't have to worry about here.

However as illustrated in the exampel above, the IMntpItemConverter interface only lets you control how each item is converted, but doesn't let you control the overall return value - e.g. if you wish to return something else than IReadOnlyList<MyContentItem>.

The package also contains the IMntpTypeConverter interface, which gives you additional control of the conversion.