DataRuleEvaluator.cs :  » Content-Management-Systems-CMS » Kooboo » Everest » CmsServices » DataRule » 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.Linq;
using System.Text;
using System.Data;
using System.Web.Mvc;
using System.Linq.Expressions;
using System.Collections.Generic;
using System.Collections.Specialized;

using Everest.Library.Data.Entity;
using Everest.Library.ExtensionMethod;
using Everest.CmsServices.Models;
using Everest.Library.Providers.Caching;

namespace Everest.CmsServices.DataRule{
    /// <summary>
    /// data rule eveluator
    /// </summary>
    public class DataRuleEvaluator
    {
        static IDictionary<DataRuleValueType, IDataRuleValueEvaluator> dataRuleValueExpressions = new Dictionary<DataRuleValueType, IDataRuleValueEvaluator>();
        static DataRuleEvaluator()
        {
            IDataRuleValueEvaluator expression = new ConstValueEvaluator();
            dataRuleValueExpressions.Add(expression.RuleType, expression);

            expression = new ListValueEvaluator();
            dataRuleValueExpressions.Add(expression.RuleType, expression);

            expression = new ObjectValueEvaluator();
            dataRuleValueExpressions.Add(expression.RuleType, expression);

            expression = new CountValueEvaluator();
            dataRuleValueExpressions.Add(expression.RuleType, expression);

            var referencingListEvaluator = new ReferencingListEvaluator();
            dataRuleValueExpressions.Add(referencingListEvaluator.RuleType, referencingListEvaluator);

            var referencingCountEvaluator = new ReferencingCountEvaluator();
            dataRuleValueExpressions.Add(referencingCountEvaluator.RuleType, referencingCountEvaluator);

            var referencedListEvaluator = new ReferencedListEvaluator();
            dataRuleValueExpressions.Add(referencedListEvaluator.RuleType, referencedListEvaluator);

            var referencedCountEvaluator = new ReferencedCountEvaluator();
            dataRuleValueExpressions.Add(referencedCountEvaluator.RuleType, referencedCountEvaluator);
        }


        /// <summary>
        /// Evaluates the specified data rule context.
        /// the data rule like as: Type=const:1&News=list: News:Name = {Name }&New=object:News:id={id};
        /// </summary>
        /// <param name="dataRuleContext">The data rule context.</param>
        /// <param name="dataRules">The data rules.</param>
        public static void Evaluate(DataRuleContext dataRuleContext, IEnumerable<Cms_DataRule> dataRules)
        {
            var oldQueryString = dataRuleContext.QueryString;
            var userControl = dataRuleContext.UserControl;
            foreach (var item in dataRules)
            {
                dataRuleContext.QueryString = new NameValueCollection(oldQueryString);
                if (userControl != null)
                {
                    //get the control property value for the queryStatement...
                    ContentQueryStatementInterpreter.CombinePropertyValues(userControl, dataRuleContext.QueryString, item.ValueRule);
                }
                var expression = dataRuleValueExpressions[(DataRuleValueType)item.ValueType];
                if (expression != null)
                {
                    object value = null;
                    TimeSpan? cacheTime = null;
                    if (!StringExtensions.IsNullOrEmptyTrim(item.Caching))
                    {
                        cacheTime = TimeSpan.Parse(item.Caching);
                    }
                    value = expression.Evaluate(dataRuleContext, item, cacheTime);
                    if (!dataRuleContext.ViewData.ContainsKey(item.DataName))
                    {
                        dataRuleContext.ViewData.Add(item.DataName, value);
                    }
                    else
                    {
                        dataRuleContext.ViewData[item.DataName] = value;
                    }
                }

            }
            //reset the usercontrol
            dataRuleContext.QueryString = oldQueryString;

        }
    }
}