Completes: U4-3261 Ensure label/readonly displays pre-values

src/Umbraco.Web.UI.Client/src/views/prevalueeditors/readonly.html

@@ -0,0 +1,7 @@
+<div ng-show="model.value.length > 0">
+    <ul>
+        <li ng-repeat="preVal in model.value">
+            <i>{{preVal.Key}}</i>&nbsp;:&nbsp;<strong>{{preVal.Value}}</strong>   
+        </li>
+    </ul>        
+</div>

src/Umbraco.Web/PropertyEditors/LabelPropertyEditor.cs

@@ -1,6 +1,9 @@
-using System.ComponentModel;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Linq;
 using System.Web.Mvc;
 using Umbraco.Core;
+using Umbraco.Core.Models;
 using Umbraco.Core.PropertyEditors;
 
 namespace Umbraco.Web.PropertyEditors
@@ -14,5 +17,39 @@ namespace Umbraco.Web.PropertyEditors
             return new LabelPropertyValueEditor(base.CreateValueEditor());
         }
 
+        protected override PreValueEditor CreatePreValueEditor()
+        {
+            return new LabelPreValueEditor();
+        }
+
+        internal class LabelPreValueEditor : PreValueEditor
+        {
+            public LabelPreValueEditor()
+            {
+                Fields.Add(new PreValueField()
+                {
+                    HideLabel = true,
+                    View = "readonly",
+                    Key = "values"
+                });
+            }
+
+            /// <summary>
+            /// Chuck all the values into one field so devs can see what is stored there - we want this in case we've converted a legacy proeprty editor over to a label
+            /// we should still show the pre-values stored for the data type.
+            /// </summary>
+            /// <param name="defaultPreVals"></param>
+            /// <param name="persistedPreVals"></param>
+            /// <returns></returns>
+            public override IDictionary<string, object> ConvertDbToEditor(IDictionary<string, object> defaultPreVals, PreValueCollection persistedPreVals)
+            {
+                var existing = base.ConvertDbToEditor(defaultPreVals, persistedPreVals);
+                //convert to a list, easier to enumerate on the editor
+                var asList = existing.Select(e => new KeyValuePair<string, object>(e.Key, e.Value)).ToList();
+                var result = new Dictionary<string, object> { { "values", asList } };
+                return result;
+            }
+        }
+
     }
 }