Content Selector with page preview

ExtendedContentReferenceSelctorAttribute.cs

public class ExtendedContentReferenceSelctorAttribute : Attribute, IMetadataAware
{
    public void OnMetadataCreated(ModelMetadata metadata)
    {
        ((ExtendedMetadata)metadata).ClientEditingClass = "alloy.editors.extendedContentSelector";
    }
}

extendedContentSelector.js

define([
        "dojo/_base/declare",
        "dojo/_base/lang",
        "dojo/on",
        "epi-cms/widget/ContentSelector",

        // resources
        "epi/i18n!epi/cms/nls/episerver.shared.header"
    ],
    function(
        declare,
        lang,
        on,
        ContentSelector,
        headingResources
    ) {
        return declare("alloy.editors.extendedContentSelector", [ContentSelector], {
            contentId: null,
            contentUri: null,
            contentTypeName: null,

            _updateDisplayNode: function (content) {
                this.contentUri = content.uri;
                this.contentId = content.contentLink;
                this.contentTypeName = content.contentTypeName;

                this.inherited(arguments);
            },

            _updateDisplayNodeTitle: function () {
                this.inherited(arguments);
                this.resourceName.title = this.resourceName.title + ", " + headingResources.id + ": " + this.contentId + " (" + headingResources.type + ": " + this.contentTypeName + ")";
            },

            buildRendering: function () {
                this.inherited(arguments);
                on(this.resourceName, "dblclick", lang.hitch(this, function () {
                    var contextParameters = { uri: this.contentUri };
                    dojo.publish("/epi/shell/context/request", [contextParameters]);
                }));
            }
        });
    });

SitePageData.cs

public abstract class SitePageData : EPiServer.Core.PageData
{
    [Display(GroupName = SystemTabNames.Content)]
    [UIHint(UIHint.Image)]
    [ExtendedContentReferenceSelctor]
    public virtual ContentReference PageImage { get; set; }
}