ContentQueryable.cs :  » Content-Management-Systems-CMS » Kooboo » Everest » CmsServices » LINQ » C# / CSharp Open Source

/*
Kooboo is a content management system based on ASP.NET MVC framework. Copyright 2009 Yardi Technology Limited.

This program is free software: you can redistribute it and/or modify it under the terms of the
GNU General Public License version 3 as published by the Free Software Foundation.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program.
If not, see http://www.kooboo.com/gpl3/.
*/

using System;
using System.Web;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Linq.Expressions;
using System.Collections;

using Everest.CmsServices.MvcHelper;
namespace Everest.CmsServices.LINQ{
    public abstract class ContentQueryable<T> : IQueryable<T>, IOrderedQueryable<T>
    {
        Expression expression;
        public ContentQueryable()
        {
            this.expression = new StatementExpression(true, typeof(ContentQueryable<T>));
        }

        public ContentQueryable(Expression expression)
        {
            if (expression == null)
            {
                throw new ArgumentNullException("expression");
            }
            if (!typeof(IQueryable<T>).IsAssignableFrom(expression.Type))
            {
                throw new ArgumentOutOfRangeException("expression");
            }

            this.expression = expression;
        }
        #region IQueryable Members

        public Type ElementType
        {
            get { return typeof(ContentContainer); }
        }

        public System.Linq.Expressions.Expression Expression
        {
            get { return expression; }
        }

        public abstract IQueryProvider Provider { get; }

        public IEnumerator<T> GetEnumerator()
        {
            return ((IEnumerable<T>)this.Provider.Execute(this.expression)).GetEnumerator();
        }
        IEnumerator IEnumerable.GetEnumerator()
        {
            return ((IEnumerable)this.Provider.Execute(this.expression)).GetEnumerator();
        }
        #endregion       
    }
}