Hi Andy,

Which version of Umbraco are you using?

Just to note, I haven't personally used Ditto with the new Udi values yet... so you may well be treading on new ground - prepare yourself for some back & forth on this. :-)

Having a peek at the Umbraco core source, it looks like the issue is with the property-value-converter for the new MediaPicker2 - specifically these lines...

https://github.com/umbraco/Umbraco-CMS/blob/dev-v7/src/Umbraco.Web/PropertyEditors/ValueConverters/MediaPickerPropertyConverter.cs#L171-L201

What's happening is that if the converter can't find any media items, it will return an empty array of Udis. Which would then get passed back to Ditto... and Ditto has no idea what to do with it.

On a side note, I can't say that I'm happy that the core value-converter is returning wildly different object-types - makes it difficult to know what we should expect.

Though it looks like someone else raised an issue about it, #U4-10160 + comments on the PR, which got rejected.

If it returned null, then Ditto could handle that scenario.

So in order to fix this, either a custom Ditto processor or a generic .NET TypeConverter would need to be created... (or potentially a PR/update to Ditto's UmbracoPicker processor?)

How are your C# skills? :-)

Cheers,
- Lee

Hi Lee,

Sorry for the late reply I'm a bit swamped at work at the moment. After reading thorugh the resources you've linked to I have to agree that I think the return type should be the default of the requested type. If the property converter doesn't know how to convert it or it's empty then the default value should be returned. Otherwise my application is going to break!

I'm still getting to grips with Umbraco, this being my first project, so I wouldn't want to suggest a solution but for the time being creating the custom MediaPickerPropertyConverter has worked a treat.

Thanks for your time, I'll go with this solution and keep an eye on any changes in the source code.

Andy

Hey Lee,

I love the tech, I've been in the industry for 15 years! But I think it's a little early for me to speak with any authority about Umbraco. :)

I'm certainly enjoying Umbraco so far and will hopefully be able to contribute in the future.

Thanks again.

Andy

Hi Andy and Lee,

Could I maybe get some help with this same issue - my back end skills are not the best so I am having a bit of trouble understanding the solution Lee suggested.

I initially had a MultimediaPicker field set to the following property on my model:

[UmbracoPicker]
public IEnumerable<ImageModel> Images { get; set; }

The ImageModel

    [UmbracoPicker]
    public class ImageModel
    {
          [UmbracoProperty("umbracoWidth")]
              public virtual int Width { get; set; }

              [UmbracoProperty("umbracoHeight")]
          public virtual int Height { get; set; }

          public string Name { get; set; }

          public virtual int Id { get; set; }

          public virtual string Url { get; set; }

          [UmbracoProperty("umbracoBytes")]
          public virtual int Size { get; set; }

          [UmbracoProperty("umbracoExtension")]
          public virtual int Type { get; set; }

          [UmbracoProperty("type")]
          public string FileType { get; set; }
     }

On a previous version of umbraco ditto (0.10.0) this mapping would work fine and all media items would get converted into ImageModels, however, now I can only get it to work if on my main Model I change the IEnumerable to:

[UmbracoPicker]
public IEnumerable<IPublishedContent> Images { get; set; }

Any suggestions to fix this? Or maybe a few more steps to implement the solution proposed? (should I downgrade Umbraco Ditto?)

Thank you, Paciencia

chiming in a bit late on this one but i've just hit the exact same problem with a new site i'm working on...

i've created a datatype based on the 'Media Picker' property editor (MediaPicker2) but set it so it can only pick a single image (which according to https://our.umbraco.org/documentation/getting-started/backoffice/property-editors/built-in-property-editors/Media-Picker2 should return a single item of IPublishedContent.

i'm running my images through a processor as i'm setting the absolute url so my set up is slightly different but this was my 'hack' way round the problem:

public class ImagePickerAttribute : DittoProcessorAttribute
{
    private readonly HttpContextBase _httpContext;
    private readonly IModelConverter _modelConverter;

    public ImagePickerAttribute()
    {
        _httpContext = DependencyResolver.Current.GetService<HttpContextBase>();
        _modelConverter = DependencyResolver.Current.GetService<IModelConverter>();
    }

    public ImagePickerAttribute(HttpContextBase httpContext, IModelConverter modelConverter)
    {
        _httpContext = httpContext;
        _modelConverter = modelConverter;
    }

    public override object ProcessValue()
    {
        if (string.Equals(Value?.ToString(), "Umbraco.Core.Udi[]", StringComparison.CurrentCultureIgnoreCase))
        {
            return null;
        }

        var image = _modelConverter.ToModel<MediaImageModel>((IPublishedContent)Value);

        image.UrlAbsolute = _httpContext?.Request.Url == null ? image.Url : $"{_httpContext.Request.Url.GetLeftPart(UriPartial.Authority)}{image.Url}";

        return image;
    }
}

feels kinda stinky but it does work! what i can't figure out is why umbraco is changing it's return type i.e. if no image is selected you get 'Umbraco.Core.Udi[]' and if an image is selected you get a piece of IPublishedContent?

tricky...

is working on a reply...