Hi Markus,

You'll need to de-register the existing (core) property-value converter, like this...

namespace Our.Umbraco.Web
{
    public class Bootstrapper : ApplicationEventHandler
    {
        protected override void ApplicationStarting(UmbracoApplicationBase umbracoApplication, ApplicationContext applicationContext)
        {
            PropertyValueConvertersResolver.Current.RemoveType<Umbraco.Web.PropertyEditors.ValueConverters.MultiNodeTreePickerPropertyConverter>();
        }
    }
}

Then your custom converter will be picked up by Umbraco core's startup code.

Cheers,
- Lee

Hi Markus,

Ah ok, then yes - currently only one property value converter can be registered to a property-editor.

The .GetPropertyValue<T> method doesn't add any influence to the value-converter at all. The <T> bit is ultimately used by the TryConvertTo<T> extension method, of which a .NET TypeConverter could be registered and used to convert from one object-type to another.

It requires a bit more code, but it's possible.

Let me know if that doesn't make sense, I'll try to provide code snippets.

Cheers,
- Lee

Hi!

So if I understand you correct, since there is only one property value converter per property editor - I need to go with my custom converter, that returns a udi, and then hook into the TryConvertTo-extention and handle when there is a IPublishContent-type parameter to this method?

If you have any hints on how to do the last part that would be very much appreciated.

Thanks again Lee!

Hi Lee!

What a hero you are, thanks for explaining this in a very clear way!

I'll try to get this working and get back when I have something running.

Thanks man!

// m

Thanks Lee!

I got it to work!

public class MyUdiConverterType : TypeConverter
{
    public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType)
    {
        if (destinationType == typeof(IPublishedContent) || 
            destinationType == typeof(IEnumerable<IPublishedContent>) || 
            destinationType == typeof(List<IPublishedContent>) || 
            destinationType == typeof(IList<IPublishedContent>))
            return true;

        return base.CanConvertTo(context, destinationType);
    }

    public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType)
    {
        var helper = new UmbracoHelper(UmbracoContext.Current);

        // deal with single items
        if (destinationType == typeof(IPublishedContent))
        {
            if (value is GuidUdi guidUdi)
                return helper.TypedContent(guidUdi.Guid);
        }

        // deal with multiple items
        if (destinationType == typeof(IEnumerable<IPublishedContent>))
        {
            if (value is IEnumerable<GuidUdi> guidUdis)
            {
                var list = new List<IPublishedContent>();
                foreach (var item in guidUdis)
                {
                    list.Add(helper.TypedContent(item.Guid));
                }

                return list;
            }

        }

        return base.ConvertTo(context, culture, value, destinationType);
    }
}

My custom property value converter

[PropertyValueType(typeof(IEnumerable<GuidUdi>))]
[PropertyValueCache(PropertyCacheValue.Object, PropertyCacheLevel.ContentCache)]
[PropertyValueCache(PropertyCacheValue.Source, PropertyCacheLevel.Content)]
[PropertyValueCache(PropertyCacheValue.XPath, PropertyCacheLevel.Content)]
public class MultiNodeTreePickerPropertyConverter : PropertyValueConverterBase
{
    public override bool IsConverter(PublishedPropertyType propertyType)
    {
        if (propertyType.PropertyEditorAlias.Equals(Constants.PropertyEditors.MultiNodeTreePicker2Alias))
            return true;

        return false;
    }

    public override object ConvertDataToSource(PublishedPropertyType propertyType, object source, bool preview)
    {

        if (propertyType.PropertyEditorAlias.Equals(Constants.PropertyEditors.MultiNodeTreePicker2Alias))
        {
            var nodeIds = source.ToString()
                .Split(new[] {","}, StringSplitOptions.RemoveEmptyEntries)
                .Select(GuidUdi.Parse).ToList();

            return nodeIds;
        }
        return null;
    }

    public override object ConvertSourceToObject(PublishedPropertyType propertyType, object source, bool preview)
    {
        if (source == null)
        {
            return null;
        }

        return (IEnumerable<GuidUdi>) source;

    }

}

And then the registration during startup:

public class Startup : ApplicationEventHandler
{
    protected override void ApplicationStarting(UmbracoApplicationBase umbracoApplication, ApplicationContext applicationContext)
    {
        PropertyValueConvertersResolver.Current.RemoveType<Umbraco.Web.PropertyEditors.ValueConverters.MultiNodeTreePickerPropertyConverter>();

        TypeDescriptor.AddAttributes(typeof(GuidUdi), new TypeConverterAttribute(typeof(MyUdiConverterType)));
        TypeDescriptor.AddAttributes(typeof(IEnumerable<GuidUdi>), new TypeConverterAttribute(typeof(MyUdiConverterType)));
    }

}

Then my view will return a List of GuidUdi's when not providing the type parameter, but when I provide the type parameter I get IPublishedContent back.

  <p>
        @Umbraco.Field("relatedContent")
  </p>    
   <p>
   Val:
   @{
        var test = Model.Content.GetPropertyValue<IEnumerable<IPublishedContent>>("relatedContent");
     }

   @if (test != null)
   {
      <text>Count:</text> @test.Count()
  }

Thanks a lot for taking the time to help me on this one! #h5yr!

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