C# Language Extension Methods Using Extension methods with Static methods and Callbacks
Example
Consider using Extension Methods as Functions which wrap other code, here's a great example that uses both a static method and and extension method to wrap the Try Catch construct. Make your code Bullet Proof...
using System;
using System.Diagnostics;
namespace Samples
{
/// <summary>
/// Wraps a try catch statement as a static helper which uses
/// Extension methods for the exception
/// </summary>
public static class Bullet
{
/// <summary>
/// Wrapper for Try Catch Statement
/// </summary>
/// <param name="code">Call back for code</param>
/// <param name="error">Already handled and logged exception</param>
public static void Proof(Action code, Action<Exception> error)
{
try
{
code();
}
catch (Exception iox)
{
//extension method used here
iox.Log("BP2200-ERR-Unexpected Error");
//callback, exception already handled and logged
error(iox);
}
}
/// <summary>
/// Example of a logging method helper, this is the extension method
/// </summary>
/// <param name="error">The Exception to log</param>
/// <param name="messageID">A unique error ID header</param>
public static void Log(this Exception error, string messageID)
{
Trace.WriteLine(messageID);
Trace.WriteLine(error.Message);
Trace.WriteLine(error.StackTrace);
Trace.WriteLine("");
}
}
/// <summary>
/// Shows how to use both the wrapper and extension methods.
/// </summary>
public class UseBulletProofing
{
public UseBulletProofing()
{
var ok = false;
var result = DoSomething();
if (!result.Contains("ERR"))
{
ok = true;
DoSomethingElse();
}
}
/// <summary>
/// How to use Bullet Proofing in your code.
/// </summary>
/// <returns>A string</returns>
public string DoSomething()
{
string result = string.Empty;
//Note that the Bullet.Proof method forces this construct.
Bullet.Proof(() =>
{
//this is the code callback
result = "DST5900-INF-No Exceptions in this code";
}, error =>
{
//error is the already logged and handled exception
//determine the base result
result = "DTS6200-ERR-An exception happened look at console log";
if (error.Message.Contains("SomeMarker"))
{
//filter the result for Something within the exception message
result = "DST6500-ERR-Some marker was found in the exception";
}
});
return result;
}
/// <summary>
/// Next step in workflow
/// </summary>
public void DoSomethingElse()
{
//Only called if no exception was thrown before
}
}
}
