ExcelQueryable.cs

using System.Collections.Generic;
using System.Linq;
using Remotion.Linq;
using System.Linq.Expressions;
using LinqToExcel.Attributes;
using System;

using LinqToExcel.Logging;

using Remotion.Linq.Parsing.Structure;

namespace LinqToExcel.Query
{
    public class ExcelQueryable<T> : QueryableBase<T>
    {
        private static IQueryExecutor CreateExecutor(ExcelQueryArgs args, ILogManagerFactory logManagerFactory)
        {
            return new ExcelQueryExecutor(args, logManagerFactory);
        }

        // This constructor is called by users, create a new IQueryExecutor.
        internal ExcelQueryable(ExcelQueryArgs args, ILogManagerFactory logManagerFactory)
            : base( QueryParser.CreateDefault(), CreateExecutor(args, logManagerFactory) )
        {
            foreach (var property in typeof(T).GetProperties())
            {
                ExcelColumnAttribute att = (ExcelColumnAttribute)Attribute.GetCustomAttribute(property, typeof(ExcelColumnAttribute));
                if (att != null && !args.ColumnMappings.ContainsKey(property.Name))
                {
                    var columnNames = ExcelUtilities.GetColumnNames(args);

                    args.ColumnMappings.Add(property.Name, !att.IsForced ? 
                        att.ColumnName : 
                        columnNames.ToList().Find(x => att.HasSimilarColumn(x))??att.ColumnName);
                }
            }
        }

        // This constructor is called indirectly by LINQ's query methods, just pass to base.
        public ExcelQueryable(IQueryProvider provider, Expression expression)
            : base(provider, expression)
        { }
    }
}