Question

I have some logging logic I want to call before and after several methods. Each method accepts different number/type of parameters. I’m trying to set it up so I don’t have to duplicate the logging logic when I call each method. I’ve been able to reduce the amount of duplication by creating some delegates. I’ve created a delegate for each number/type of parms used and I have a method that accepts each delegate and does the logging. However, I still have around 6 different delegates and so the logic is duplicated for those six.

I think there is away to modify this so regardless of the number of parms, I have one method that does the logging and calls the method. But I haven’t been able to figure it out.

Below is an example of one of the delegates and the logic I’m trying not to duplicate.

    public delegate void LineOfBusinessHandler(DateTime runDate, LineOfBusinessCode lineOfBusinessCode);

    public void Run(DateTime runDate, ProcessCode process, LineOfBusinessCode lineOfBusinessCode, LineOfBusinessHandler del)
    {
        this.ProcessManager.AddToBatchLog(process.ToString(), ProcessStatus.Started.ToString(), null, runDate);


        try
        {
            del(runDate, lineOfBusinessCode);
            this.ProcessManager.AddToBatchLog(process.ToString(), ProcessStatus.Finished.ToString(), null, runDate);
        }
        catch (Exception e)
        {
            int errorId = SystemManager.LogError(e, process.ToString());
            this.ProcessManager.AddToBatchLog(process.ToString(), ProcessStatus.Errored.ToString(), errorId, runDate);
        }
    }

Answer 1

It depends on what is common among the different versions, but assuming runDate and process are common you could do something like this:

public void Run(DateTime runDate, ProcessCode process, LineOfBusinessCode lineOfBusinessCode, LineOfBusinessHandler del)
{
    this.DoRun(runDate, process, (d, p) => del(d, p, lineOfBusinessCode));
}

public void DoRun(DateTime runDate, ProcessCode process, Action<DateTime, ProcessCode> action)
{
    this.ProcessManager.AddToBatchLog(process.ToString(), ProcessStatus.Started.ToString(), null, runDate);


    try
    {
        action(runDate, process);
        this.ProcessManager.AddToBatchLog(process.ToString(), ProcessStatus.Finished.ToString(), null, runDate);
    }
    catch (Exception e)
    {
        int errorId = SystemManager.LogError(e, process.ToString());
        this.ProcessManager.AddToBatchLog(process.ToString(), ProcessStatus.Errored.ToString(), errorId, runDate);
    }
}

You can even generalize so you don’t have do define custom delegates as this:

public void Run<T1>(DateTime runDate, ProcessCode process, T1 param1, Action<DateTime, ProcessCode, T1> del)
{
    this.DoRun(runDate, process, (d, p) => del(d, p, param1));
}

public void Run<T1, T2>(DateTime runDate, ProcessCode process, T1 param1, T2 param2, Action<DateTime, ProcessCode, T1, T2> del)
{
    this.DoRun(runDate, process, (d, p) => del(d, p, param1, param2));
}