Umbraco - Fix Drop Down Pre Value Display In List Views Handler

MyUmbracoApplication.cs

#region

using System;
using System.Linq;
using System.Net.Http;
using System.Threading;
using System.Threading.Tasks;
using System.Web.Http;
using Umbraco.Core;
using Umbraco.Core.Models;
using Umbraco.Web;
using Umbraco.Web.Models.ContentEditing;

#endregion

public class MyUmbracoApplication : UmbracoApplication
{
    protected override void OnApplicationStarted(object sender, EventArgs e)
    {
        base.OnApplicationStarted(sender, e);

        GlobalConfiguration.Configuration.MessageHandlers.Add(new FixDropDownPreValueDisplayInListViewsHandler());
    }
}

public class FixDropDownPreValueDisplayInListViewsHandler : DelegatingHandler
{
    protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
    {
        // wait for the request to be processed
        var response = await base.SendAsync(request, cancellationToken);

        // ensure we're only processing requests to getchildren - hopefully only listviews
        if (request?.RequestUri?.AbsolutePath.Equals("/umbraco/backoffice/UmbracoApi/Content/GetChildren") == true)
        {
            // get the response value and cast to type returned by ContentController.GetChildren
            var content = (ObjectContent)response.Content;
            var data = content?.Value as PagedResult<ContentItemBasic<ContentPropertyBasic, IContent>>;

            foreach (var item in data?.Items)
                foreach (var prop in item?.Properties.Where(p => p?.Editor == "Umbraco.DropDown"))
                {
                    // swap the prevalue id to the string using the datatype service
                    var propStr = prop.Value?.ToString();
                    if (!propStr.IsNullOrWhiteSpace())
                        prop.Value = ApplicationContext.Current.Services.DataTypeService.GetPreValueAsString(Convert.ToInt32(prop.Value));
                }
        }

        return response;
    }
}

Thanks for the really handy code. I discovered something you might find useful: you need to wrap the outer foreach loop with a check for null. Otherwise it throws an exception when viewing the recycle bin.

if (data?.Items != null)
{
    foreach (var item in data?.Items)
    ...

I followed this suggestion and it works fine.
But I found out it will not work for member lists so I added a switch in the code.
I switch on type detected on content?.Value because for members the result is PagedResult<MemberBasic> instead of PagedResult<ContentItemBasic<ContentPropertyBasic, IContent>>

Code is triggered fine and conversion is performed. I can verify that prop.Value now has the desired display text.
BUT the strange part is that for members this does NOT affect the presented value!!!!
For members I still get the number instead of the text that I know I have replaced it with.

What happens here? Is there some changed event loop which means the member list in fact doesn't care of the value I have specified?
Any suggestions?

Hi,

Does this still work, or am I doing something wrong?

I tried to implement this to be able to see drop down prevalues in listview, but the dropdown ID's still shows. Am I missing something?

What I did was to create a ListViewPreValuesExtension.cs file in my Extensions folder and then build the solution. Do I have to do anything else to make it work?

Thanks in advance!

This still works in Umbraco 7.14 but with a few amendments.

Line 41: foreach (var prop in item?.Properties.Where(p => p?.Editor == "Umbraco.DropDown.Flexible"))

Line 46: prop.Value = ApplicationContext.Current.Services.DataTypeService.GetPreValueAsString(Convert.ToInt32(((string[])prop.Value)?[0]));