Add in Umbraco.DropdownlistPublishingKeys migrator

uSync.Migrations.Migrators/Core/DropdownlistPublishingKeysMigrator.cs

@@ -0,0 +1,57 @@
+using Newtonsoft.Json;
+using Umbraco.Cms.Core.Models;
+using Umbraco.Cms.Core.PropertyEditors;
+
+namespace uSync.Migrations.Migrators.Core;
+
+[SyncMigrator("Umbraco.DropdownlistPublishingKeys")]
+public class DropdownlistPublishingKeysMigrator : SyncPropertyMigratorBase
+{
+    public override string GetDatabaseType(SyncMigrationDataTypeProperty dataTypeProperty, SyncMigrationContext context)
+        => nameof(ValueStorageType.Nvarchar).ToLower();
+
+    public override string GetEditorAlias(SyncMigrationDataTypeProperty dataTypeProperty, SyncMigrationContext context)
+        => UmbConstants.PropertyEditors.Aliases.DropDownListFlexible;
+
+    public override object? GetConfigValues(SyncMigrationDataTypeProperty dataTypeProperty,
+        SyncMigrationContext context)
+    {
+        var config = new DropDownFlexibleConfiguration();
+
+        if (dataTypeProperty.PreValues is null)
+            return config;
+
+        int index = 0;
+
+        foreach (var preValue in dataTypeProperty.PreValues)
+        {
+            config.Items.Add(new ValueListConfiguration.ValueListItem
+            {
+                Id = index++,
+                Value = preValue.Value,
+            });
+        }
+
+        context.Migrators.AddCustomValues(
+            $"dataType_{dataTypeProperty.DataTypeAlias}_items",
+            config.Items.ToDictionary(x => x.Id.ToString(), x => (object)x.Value!));
+
+        return config;
+    }
+
+    public override string? GetContentValue(SyncMigrationContentProperty contentProperty, SyncMigrationContext context)
+    {
+        if (string.IsNullOrEmpty(contentProperty.Value)) 
+            return "[]";
+
+        var dataTypeAlias = context.ContentTypes
+            .GetDataTypeAlias(contentProperty.ContentTypeAlias, contentProperty.PropertyAlias);
+
+        var items = context.Migrators.GetCustomValues($"dataType_{dataTypeAlias}_items");
+
+        if (items.TryGetValue(contentProperty.Value, out var value) && value is string stringValue)
+            return JsonConvert.SerializeObject(new[] { stringValue });
+
+        return "[]";
+    }
+}