A .NET State Machine Toolkit - Part I

/*
 * Created by: Leslie Sanford
 * 
 * Contact: jabberdabber@hotmail.com
 * 
 * Last modified: 09/30/2005
 */

using System;
using System.CodeDom;
using System.Collections;

namespace Sanford.StateMachineToolkit
{
	/// <summary>
	/// Builds the method responsible for initializing states' history type.
	/// </summary>
    internal class HistoryInitializeBuilder
	{
        #region HistoryInitializeBuilder Members

        #region Fields

        // The state machine's states and their history types.
        private IDictionary stateHistoryTypes;

        // The built method.
        private CodeMemberMethod result = new CodeMemberMethod();

        #endregion

        #region Construction

        /// <summary>
        /// Initializes a new instance of the HistoryInitializeBuilder class.
        /// </summary>
        /// <param name="stateHistoryTypes">
        /// The states and their history types.
        /// </param>
		public HistoryInitializeBuilder(IDictionary stateHistoryTypes)
		{
            this.stateHistoryTypes = stateHistoryTypes;
		}

        #endregion

        #region Methods

        /// <summary>
        /// Builds the method.
        /// </summary>
        public void Build()
        {
            result = new CodeMemberMethod();
            result.Name = "InitializeHistoryTypes";
            result.Attributes = MemberAttributes.Private;

            CodeThisReferenceExpression thisReference = 
                new CodeThisReferenceExpression();
            CodeFieldReferenceExpression stateField;
            CodePropertyReferenceExpression historyTypeProperty;
            CodeTypeReferenceExpression historyType = new CodeTypeReferenceExpression(typeof(HistoryType));
            CodeFieldReferenceExpression historyTypeField;
            CodeAssignStatement historyTypeAssign;

            foreach(DictionaryEntry entry in stateHistoryTypes)
            {
                stateField = new CodeFieldReferenceExpression(
                    thisReference, "state" + entry.Key.ToString());

                historyTypeProperty = new CodePropertyReferenceExpression(
                    stateField, "HistoryType");

                if(entry.Value.ToString() == string.Empty ||
                    entry.Value.ToString() == null)
                {
                    historyTypeField = new CodeFieldReferenceExpression(
                        historyType, "None");
                }
                else
                {
                    historyTypeField = new CodeFieldReferenceExpression(
                        historyType, entry.Value.ToString());
                }               

                historyTypeAssign = new CodeAssignStatement(
                    historyTypeProperty, historyTypeField);

                result.Statements.Add(historyTypeAssign);
            }
        }

        #endregion

        #region Properties

        /// <summary>
        /// Gets the built method.
        /// </summary>
        public CodeMemberMethod Result
        {
            get
            {
                return result;
            }
        }

        #endregion

        #endregion
	}
}