UCommerce Datatypes Category picker with stores

Category.aspx

<%@ Control Language="C#" AutoEventWireup="true" Inherits="This.Web.usercontrols.Administrative.UCommerceDataTypesCategory" %>
<asp:UpdateProgress ID="UpdateProgress1"
    runat="server"
	AssociatedUpdatePanelID="CategoryPanel">
	<ProgressTemplate>
		<img src="/umbraco/images/throbber.gif" alt="Loading"/>
	</ProgressTemplate>	
</asp:UpdateProgress>
<asp:UpdatePanel runat="server" UpdateMode="Always" ID="CategoryPanel">
    <ContentTemplate>
        <table cellspacing="20">
	        <tr>
		        <td style="vertical-align: top; width: 30px">
		            <asp:Image ID="selectedCategoryIcon" runat="server" />
                </td>
                <td style="vertical-align: top; width: auto; padding-top: 7px">
		            <asp:Label ID="selectedCategoryLabel" runat="server" ForeColor="Black" />
                </td>
                <td style="vertical-align: top; padding-top: 6px; width: 20px">
                    <asp:ImageButton runat="server" ID="clearSelection" OnClick="clearSelection_Clicked" />
		        </td>
	        </tr>
	        <tr>
		        <td colspan="3">
			        <asp:TreeView id="treeCategory" runat="server" 
				        OnSelectedNodeChanged="treeCategory_SelectedNodeChanged"
				        OnTreeNodeExpanded="treeCategory_NodeExpanded"
				        RootNodeStyle-ForeColor="DarkGray"
                        RootNodeStyle-Font-Bold="True"
				        NodeStyle-ForeColor="Black"
				        NodeStyle-HorizontalPadding="5"
				        SelectedNodeStyle-ForeColor="Black"
				        SelectedNodeStyle-BorderStyle="Solid"
				        SelectedNodeStyle-BorderWidth="1"
				        SelectedNodeStyle-BorderColor="LightSkyBlue"
				        SelectedNodeStyle-BackColor="LightCyan"
				        ExpandDepth="0"
				        AutoPostBack="True">
				        <LevelStyles>
					        <asp:TreeNodeStyle ForeColor="DarkGray" Font-Bold="True"/>
					        <asp:TreeNodeStyle ForeColor="DarkGray" Font-Bold="True"/>
				        </LevelStyles>
				        <Nodes>
				        </Nodes>
			        </asp:TreeView>
		        </td>
	        </tr>
        </table>
    </ContentTemplate>
</asp:UpdatePanel>

UCommerceDataTypesCategory.cs

using System;
using System.Linq;
using System.Web.UI;
using System.Web.UI.WebControls;
using UCommerce.EntitiesV2;
using umbraco.editorControls.userControlGrapper;

namespace This.Web.usercontrols.Administrative
{
    public class UCommerceDataTypesCategory : UserControl, IUsercontrolDataEditor
	{
		protected UpdateProgress UpdateProgress1;
		protected UpdatePanel CategoryPanel;
		protected Image selectedCategoryIcon;
		protected Label selectedCategoryLabel;
		protected ImageButton clearSelection;
		protected TreeView treeCategory;
		private string _umbracoValue;
		private string selectedItemKey;

		public object value
		{
			get
			{
				if (treeCategory.SelectedNode != null)
					return treeCategory.SelectedNode.Value;
				return _umbracoValue;
			}
			set
			{
				if (value != null)
					_umbracoValue = value.ToString();
				else
					_umbracoValue = "";
			}
		}

		protected void Page_Load(object sender, EventArgs e)
		{
			selectedItemKey = "ucommerce_category_control_" + UniqueID;
			if (!IsPostBack)
			{
				clearSelection.ImageUrl = "/umbraco/images/close.png";

				foreach (var store in ProductCatalogGroup.All())
				{
					var child = new TreeNode(store.Name, "S" + Convert.ToString(store.ProductCatalogGroupId));
					child.ImageUrl = "/umbraco/images/umbraco/ucommerce-icon.png";
					if (store.ProductCatalogs.Any())
						child.ChildNodes.Add(new TreeNode("", "NULL_NODE"));
					treeCategory.Nodes.Add(child);
				}
				Session[selectedItemKey] = _umbracoValue;
			}
			else
				_umbracoValue = (string)Session[selectedItemKey];
			if (string.IsNullOrEmpty(_umbracoValue))
			{
				selectedCategoryIcon.ImageUrl = "/umbraco/images/speechBubble/error.png";
				selectedCategoryLabel.Text = "";
				clearSelection.Visible = false;
			}
			else if (treeCategory.SelectedNode != null)
			{
				selectedCategoryIcon.ImageUrl = "/umbraco/images/speechBubble/success.png";
				selectedCategoryLabel.Text = treeCategory.SelectedNode.Text;
				clearSelection.Visible = true;
			}
			else
			{
				var categoryId = int.Parse(this._umbracoValue);
				var category = Category.Find(c => c.CategoryId == categoryId).SingleOrDefault();
				if (category != null)
				{
					selectedCategoryIcon.ImageUrl = "/umbraco/images/speechBubble/success.png";
					selectedCategoryLabel.Text = category.Name;
					clearSelection.Visible = true;

					ExpandToCategory(category);
				}
				else
				{
					selectedCategoryIcon.ImageUrl = "/umbraco/images/speechBubble/error.png";
					selectedCategoryLabel.Text = "";
					clearSelection.Visible = false;
				}
			}
		}

		private void ExpandToCategory(Category category)
		{
			var storeNode = treeCategory.Nodes.Cast<TreeNode>().SingleOrDefault(n => n.Value == "S" + Convert.ToString(category.ProductCatalog.ProductCatalogGroup.ProductCatalogGroupId));
			if (storeNode == null)
				return;
			storeNode.Expand();
			var catalogNode = storeNode.ChildNodes.Cast<TreeNode>().SingleOrDefault(n => n.Value == "G" + Convert.ToString(category.ProductCatalog.ProductCatalogId));
			if (catalogNode == null)
				return;
			catalogNode.Expand();
			ExpandParents(category, catalogNode);
		}

		private TreeNode ExpandParents(Category category, TreeNode catalogNode)
		{
			TreeNode parent = catalogNode;
			if (category.ParentCategory != null)
				parent = ExpandParents(category.ParentCategory, catalogNode);
			var categoryNode = parent.ChildNodes.Cast<TreeNode>().SingleOrDefault(n => n.Value == Convert.ToString(category.CategoryId));
			if (categoryNode != null)
				categoryNode.Expand();
			return categoryNode;
		}

		protected void treeCategory_SelectedNodeChanged(object sender, EventArgs e)
		{
			if (treeCategory.SelectedNode.Depth > 1)
			{
				_umbracoValue = treeCategory.SelectedNode.Value;
				Session[selectedItemKey] = _umbracoValue;
				selectedCategoryIcon.ImageUrl = "/umbraco/images/speechBubble/success.png";
				selectedCategoryLabel.Text = this.treeCategory.SelectedNode.Text;
				clearSelection.Visible = true;
			}
			else if (Session[selectedItemKey] != null)
			{
				_umbracoValue = Session[selectedItemKey].ToString();
				foreach (TreeNode treeNode in treeCategory.Nodes)
				{
					if (treeNode.Value == _umbracoValue)
					{
						treeNode.Select();
						break;
					}
					if (treeNode.ChildNodes.Count > 0)
						CheckSubNodesForSelection(treeNode, _umbracoValue);
				}
				selectedCategoryIcon.ImageUrl = "/umbraco/images/speechBubble/success.png";
				selectedCategoryLabel.Text = treeCategory.SelectedNode.Text;
				clearSelection.Visible = true;
			}
			else
			{
				_umbracoValue = "";
				selectedCategoryIcon.ImageUrl = "/umbraco/images/speechBubble/error.png";
				selectedCategoryLabel.Text = "";
				clearSelection.Visible = false;
			}
		}

		protected void treeCategory_NodeExpanded(object sender, TreeNodeEventArgs e)
		{
			if (e.Node.ChildNodes.Count <= 0 || !(e.Node.ChildNodes[0].Value == "NULL_NODE"))
				return;
			e.Node.ChildNodes.RemoveAt(0);
			if (e.Node.Depth == 0)
			{
				var storeId = int.Parse(e.Node.Value.Substring(1));
				var store = ProductCatalogGroup.Get(storeId);
				foreach (var catalog in store.ProductCatalogs)
				{
					var child = new TreeNode(catalog.Name, "G" + Convert.ToString(catalog.ProductCatalogId));
					child.ImageUrl = "/umbraco/images/umbraco/folder.gif";
					e.Node.ChildNodes.Add(child);
					if (catalog.Categories.Any())
						child.ChildNodes.Add(new TreeNode("", "NULL_NODE"));
				}
			}
			else if (e.Node.Depth == 1)
			{
				var catalogId = int.Parse(e.Node.Value.Substring(1));
				var productCatalog = ProductCatalog.Get(catalogId);
				if (productCatalog != null)
				{
					foreach (var category in productCatalog.Categories.Where(cat => cat.ParentCategory == null))
					{
						TreeNode child = new TreeNode(category.Name, Convert.ToString(category.CategoryId.ToString()));
						child.ImageUrl = "/umbraco/images/umbraco/folder.gif";
						e.Node.ChildNodes.Add(child);
						if (category.Categories.Count > 0)
							child.ChildNodes.Add(new TreeNode("", "NULL_NODE"));
						if (child.Value == _umbracoValue)
							child.Select();
					}
				}
			}
			if (e.Node.Depth > 1)
			{
				var categoryId = int.Parse(e.Node.Value);
				var category = Category.Get(categoryId);
				if (category != null)
				{
					foreach (var subCategory in category.Categories)
					{
						TreeNode child = new TreeNode(subCategory.Name, subCategory.CategoryId.ToString());
						child.ImageUrl = "/umbraco/images/umbraco/folder.gif";
						e.Node.ChildNodes.Add(child);
						if (subCategory.Categories.Count > 0)
							child.ChildNodes.Add(new TreeNode("", "NULL_NODE"));
						if (child.Value == _umbracoValue)
							child.Select();
					}
				}
			}
		}

		private void CheckSubNodesForSelection(TreeNode treeNode, string valueToSelect)
		{
			foreach (TreeNode childNode in treeNode.ChildNodes)
			{
				if (childNode.Value == valueToSelect)
				{
					childNode.Select();
					break;
				}
				if (childNode.ChildNodes.Count > 0)
					CheckSubNodesForSelection(childNode, valueToSelect);
			}
		}

		protected void clearSelection_Clicked(object sender, EventArgs e)
		{
			_umbracoValue = "";
			Session[selectedItemKey] = (object)null;
			treeCategory.CollapseAll();
			selectedCategoryIcon.ImageUrl = "/umbraco/images/speechBubble/error.png";
			selectedCategoryLabel.Text = "";
			clearSelection.Visible = false;
		}
	}
}