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Custom Rule Engine in WPF - MVVM

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11 Sep 2010CPOL8 min read 75.4K   1.3K   95  
Custom Rule Engine approach which can evaluate complex combinations of business rules. A sample application is provided in WPF following the MVVM pattern.
using System.Collections.Generic;
using System.Windows.Input;
using CustomRulesMVVM.Models;

namespace CustomRulesMVVM.ViewModels
{
    class CountryViewModel:BaseViewModel
    {
        #region Members
        private const string COUNTRY = "COUNTRY";
        private Country _country = new Country();
        private RelayCommand _searchCountry;
        private string _searchCountryResult;
        Dictionary<string, object> collection = new Dictionary<string, object>();
        #endregion

        #region Properties
        /// <summary>
        /// Country name entered by user
        /// </summary>
        public string MyCountry 
        {
            get { return this._country.CountryName; }
            set
            {
                this._country.CountryName  = value;
                base.OnProperyChanged("MyCountry");                
            }
        }
        /// <summary>
        /// Search result
        /// </summary>
        public string SearchCountryResult
        {
            get { return this._searchCountryResult; }
            set
            {
                this._searchCountryResult = value;
                base.OnProperyChanged("SearchCountryResult");
            }
        }
        /// <summary>
        /// Command for button to search country
        /// </summary>
        public ICommand SearchCountry
        {
            get
            {
                if (null == this._searchCountry)
                {
                    this._searchCountry = new RelayCommand(param => this.SearchCountryDetails());
                }
                return this._searchCountry;
            }
        }
        #endregion

        #region Private Methods
        /// <summary>
        /// Searching country by firt populating the custom rules and evaluating rules by passing the Country object
        /// </summary>
        private void SearchCountryDetails()
        { 
            //Clear the result 
            this.SearchCountryResult = string.Empty;
            //Populate custom rules applicable for this screen by passing the ScreenID (here ScreenID =1)
            this.PopulateCustomRules(1);
            collection[COUNTRY] = _country;
            //Evaluate the rules for Country screen
            this.SearchCountryResult = this.EvaluateCustomRules(collection); 
        }               
        #endregion
    }
}

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This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


Written By
Software Developer (Senior) CA-CIB
Singapore Singapore
I am a .Net developer, currently working in Singapore worked wiith Societe Generale Global Solution Centre, Bangalore and was previously with Cognizant.I have more than 8 years of .Net experience in BFSI domain. I am an experienced developer in C#, VB.Net, Silverlight, WPF, WCF, LINQ, Entity Framework, SSIS, NHibernate, ASP.Net and SQL Server.

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