Sample 2 : Template Method Design Pattern

Sample2.TemplateMethod.cs

class Program
{
    static void Main(string[] args)
    {
        BaseProcessor reportProcessor = null;

        reportProcessor = new ImportReportProcessor();
        reportProcessor.ProcessorCompleted += reportProcessor_ProcessorCompleted;
        reportProcessor.ProcessorStarting += reportProcessor_ProcessorStarting;
        reportProcessor.ProcessorStarted += reportProcessor_ProcessorStarted;

        // to getting import report
        reportProcessor.Process();

        reportProcessor = new ExportReportProcessor();

        // to getting export report
        reportProcessor.Process();


        Console.ReadLine();
    }

    static void reportProcessor_ProcessorStarted(object sender, ProcessorEventArg e)
    {
        Console.WriteLine("Started");
    }

    static void reportProcessor_ProcessorStarting(object sender, ProcessorEventArg e)
    {
        Console.WriteLine("Starting");
    }

    static void reportProcessor_ProcessorCompleted(object sender, ProcessorEventArg e)
    {
        Console.WriteLine("Completed");
    }
}

public class ProcessorEventArg
    : EventArgs
{

}

public class ProcessorStatus
{
    public enum Current
    {
        Starting = 1,
        Started = 2,
        Completing = 3,
        Completed = 4,
        Error = 5
    }
}

public interface IProcessor
{
    void Process();
}

/// <summary>
/// Abstract Class
/// </summary>
public abstract class BaseProcessor
    : IProcessor
{
    public delegate void ProcessorStartingEventHandler(object sender, ProcessorEventArg e);
    public delegate void ProcessorStartedEventHandler(object sender, ProcessorEventArg e);
    public delegate void ProcessorCompletedEventHandler(object sender, ProcessorEventArg e);
    public delegate void ProcessorErrorEventHandler(object sender, ProcessorEventArg e);

    public event ProcessorStartingEventHandler ProcessorStarting = null;
    public event ProcessorStartedEventHandler ProcessorStarted = null;
    public event ProcessorCompletedEventHandler ProcessorCompleted = null;
    public event ProcessorErrorEventHandler ProcessorError = null;

    public ProcessorStatus.Current Status { get; private set; }

    protected virtual void OnProcessorStarting(ProcessorEventArg e)
    {
        if (ProcessorStarting != null)
            ProcessorStarting(this.GetType(), e);
    }

    protected virtual void OnProcessorStarted(ProcessorEventArg e)
    {
        if (ProcessorStarted != null)
            ProcessorStarted(this.GetType(), e);
    }

    protected virtual void OnProcessorCompleted(ProcessorEventArg e)
    {
        if (ProcessorCompleted != null)
            ProcessorCompleted(this.GetType(), e);
    }

    protected virtual void OnProcessorError(ProcessorEventArg e)
    {
        if (ProcessorError != null)
            ProcessorError(this.GetType(), e);
    }

    // Primitive Methods
    public abstract void GetReportDefinitions();
    public abstract void RunReportJob();
    public abstract void ValidateReport();
    public abstract void CreateReportFile();
    public abstract void ExtractReportFile();


    // Template Method
    public void Process()
    {
        ProcessorEventArg e = new ProcessorEventArg();

        // starting loging for real job's log table
        this.Status = ProcessorStatus.Current.Starting;
        OnProcessorStarting(e);

        SubProcess(e);
    }

    public void SubProcess(ProcessorEventArg e)
    {
        // started loging
        this.Status = ProcessorStatus.Current.Started;
        OnProcessorStarted(e);

        try
        {
            GetReportDefinitions();
            RunReportJob();
            ValidateReport();
            CreateReportFile();
            ExtractReportFile();

        }
        catch (Exception ex)
        {
            this.Status = ProcessorStatus.Current.Error;
            OnProcessorError(e);
            // error logging
        }

        // completing loging
        this.Status = ProcessorStatus.Current.Completing;
        OnProcessorCompleted(e);

        // completed loging
        this.Status = ProcessorStatus.Current.Completed;
    }

}

/// <summary>
/// Concrete Class
/// </summary>
public class ImportReportProcessor
    : BaseProcessor
{
    // primitive method 1
    public override void GetReportDefinitions()
    {
        Console.WriteLine("ImportReportProcessor.GetReportDefinitions");
    }

    // primitive method 2
    public override void RunReportJob()
    {
        Console.WriteLine("ImportReportProcessor.RunReportJob");
    }

    // primitive method 3
    public override void ValidateReport()
    {
        Console.WriteLine("ImportReportProcessor.ValidateReport");
    }

    // primitive method 4
    public override void CreateReportFile()
    {
        Console.WriteLine("ImportReportProcessor.CreateReportFile");
    }

    // primitive method 5
    public override void ExtractReportFile()
    {
        Console.WriteLine("ImportReportProcessor.ExtractReportFile");
    }
}

/// <summary>
/// Concrete Class
/// </summary>
public class ExportReportProcessor
    : BaseProcessor
{
    // primitive method 1
    public override void GetReportDefinitions()
    {
        Console.WriteLine("ExportReportProcessor.GetReportDefinitions");
    }

    // primitive method 2
    public override void RunReportJob()
    {
        Console.WriteLine("ExportReportProcessor.RunReportJob");
    }

    // primitive method 3
    public override void ValidateReport()
    {
        Console.WriteLine("ExportReportProcessor.ValidateReport");
    }

    // primitive method 4
    public override void CreateReportFile()
    {
        Console.WriteLine("ExportReportProcessor.CreateReportFile");
    }

    // primitive method 5
    public override void ExtractReportFile()
    {
        Console.WriteLine("ExportReportProcessor.ExtractReportFile");
    }
}