Filtering LINQ Queries Using Business Rules Engine

using System.Linq;
using System.Web.Mvc;
using System.Reflection;
using System.Data.Objects;
using System.Data.Objects.DataClasses;
using System.Collections.Generic;
using CodeEffects.Rule.Common;


namespace CodeEffects.Rule.Demo.Filter.Mvc.Models
{
	// The utility service that is used to get static data for drop downs
	// and dynamic menu data sources (read more about them here:
	// http://rule.codeeffects.com/Doc/Business-Rules-Dynamic-Menu-Data-Sources)
	public class Utility
	{
		public static List<SelectListItem> GetEntities()
		{
			List<SelectListItem> entities = new List<SelectListItem>();
			entities.Add(new SelectListItem { Text = "Customers", Value = "Customers" });
			entities.Add(new SelectListItem { Text = "Products", Value = "Products" });
			entities.Add(new SelectListItem { Text = "Orders", Value = "Orders" });
			return entities;
		}
		public static List<SelectListItem> GetThemes()
		{
			List<SelectListItem> themes = new List<SelectListItem>();
			themes.Add(new SelectListItem { Text = ThemeType.Gray.ToString(), Value = ThemeType.Gray.ToString() });
			themes.Add(new SelectListItem { Text = ThemeType.Blue.ToString(), Value = ThemeType.Blue.ToString() });
			themes.Add(new SelectListItem { Text = ThemeType.Green.ToString(), Value = ThemeType.Green.ToString() });
			themes.Add(new SelectListItem { Text = ThemeType.Red.ToString(), Value = ThemeType.Red.ToString() });
			themes.Add(new SelectListItem { Text = ThemeType.White.ToString(), Value = ThemeType.White.ToString() });
			themes.Add(new SelectListItem { Text = ThemeType.Navy.ToString(), Value = ThemeType.Navy.ToString() });
			themes.Add(new SelectListItem { Text = ThemeType.Black.ToString(), Value = ThemeType.Black.ToString() });
			return themes;
		}

		public static List<DataSourceItem> GetCountries()
		{
			return GetLookupItems<Country>(new WebRuleLinqEntities().Countries, typeof(Country).GetProperty("Name"));
		}
		public static List<DataSourceItem> GetColors()
		{
			return GetLookupItems<Color>(new WebRuleLinqEntities().Colors, typeof(Color).GetProperty("Name"));
		}
		public static List<DataSourceItem> GetSizes()
		{
			return GetLookupItems<Size>(new WebRuleLinqEntities().Sizes, typeof(Size).GetProperty("Name"));
		}
		public static List<DataSourceItem> GetProductTypes()
		{
			return GetLookupItems<ProductType>(new WebRuleLinqEntities().ProductTypes, typeof(ProductType).GetProperty("Name"));
		}

		private static List<DataSourceItem> GetLookupItems<T> (ObjectSet<T> items, PropertyInfo pi) where T: EntityObject, new()
		{
			List<DataSourceItem> list = new List<DataSourceItem>();

			var q = from c in items.OrderBy("it.Name")
					select c;

			foreach(var item in q)
				list.Add(
					new DataSourceItem(
						(int)item.EntityKey.EntityKeyValues[0].Value,
						pi.GetValue(item, null).ToString()));

			return list;
		}
	}
}