ASP.NET Web Component for editing SQL tables

/*
 * Code Copyright 2012 by Bill Frisbie
 * 
 * This code is licensed under COPL license.
 * Users are free to use this code, modify it and include it in other work, including works for resale.
 * Please include this notice in the code.
 * Author provides code 'as-is', and assumes no liability for any losses whatsoever arising from its use
 * Contact author at bfrisbie@optonline.net with any questions or suggestions.
 */
using System;
using System.Collections.Generic;
using System.Text;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace BFCS.Data.Common
{
    /// <summary>
    /// Interface that must be implemented by a table adapter
    /// </summary>
    /// <remarks>
    /// This project defines a set of standard TableAdapter descended objects that implement this interface
    /// The interface defines methods for generating System.Web.Control objects for insertion into
    /// an <see>EditTable</see> table cell. The <see>ColumnTableAdapter</see> method in DbValidator class
    /// returns an instance of a standard table adapter for columns of different types.
    /// 
    /// Web sites using <see>EditTable</see> can define their own classes of the <see>TableAdapter</see>
    /// descendent that implement this interface. In order for EditTable to discover and use these custom
    /// adapters, the class must be decorated with the <see>CustomTableAdapterAttribute</see> attribute.
    /// This attribute requires that a table name and column name be declared, identifying which column
    /// the custom adapter applies to. Optionally, a string Modifiers can be declared. The string's usage
    /// is up to the implementation of the custom adapter. Typical uses are to define min/max values,
    /// to declare a table or view to be used as the source of a dropdown list, or to define the list's values
    /// explicitly.
    /// </remarks>
    public interface ITableAdapter
    {
        /// <summary>
        /// Given a value retrieved from a data source, return a System.Web.Control to display it
        /// in a non-edit, non-append row
        /// </summary>
        /// <param name="value">retrieved value</param>
        /// <returns>Control to use</returns>
        Control DisplayValue(object value);
        /// <summary>
        /// Given a value retrieved from a data source, return a System.Web.Control to display it
        /// in an edit row
        /// </summary>
        /// <param name="value">retrieved value</param>
        /// <returns>Control to use</returns>
        Control EditValue(object value);
        /// <summary>
        /// Given a value retrieved from a data source, return a System.Web.Control to display it
        /// in an edit or append row
        /// </summary>
        /// <param name="value">retrieved value</param>
        /// <param name="Appending">flag: if true, append row; otherwise, edit row</param>
        /// <returns>Control to use</returns>
        Control EditValue(object value, bool Appending);
        /// <summary>
        /// Given a value entered as a string, check for validity, modify as necessary to use
        /// in an action SQL statement
        /// </summary>
        /// <param name="setting">entered setting</param>
        /// <param name="error">(out) string representing error, if any</param>
        /// <returns>(possibly modified) string (no delimiters)</returns>
        string SaveValue(string setting, out string error);
    }
}