Implementing Elmah in web api project

Question

I am trying to implement ELMAH in a webapi project,since I am new to this elmah technique,I am not able to implement the entire thing.I even tried to follow the sample codes in web but still I am not getting.

can someone please help me to achieve a proper working solution with elmah. I will be very thankful if a working solution is provided for demo purpose which will be really helpful for me to understand

There is already a question concerning this topic: https://stackoverflow.com/questions/10116593/how-to-set-up-elmah-with-asp-net-web-api — tschan, Dec 09 '19 at 09:08
Please check out the solution from [@ahmed-ahemd](https://stackoverflow.com/users/388788/ahmed-ahmed) here: https://stackoverflow.com/a/21856256/3974799 — tschan, Dec 09 '19 at 19:00

score 4 · Answer 1 · edited Sep 28 '17 at 03:19

Here are the steps to send error emails using Elmah

Install Elmah Nuget Package

Update config file to use proper SMTP settings. Here is the example of config file settings

< security allowRemoteAccess="false" />
< errorMail subject="Production Error - {1}: {0}" smtpServer="server address" from="me@you.com" to="you@me.com" />

Create ExceptionLogger class. Here is the example of it

public class ElmahExceptionLogger : ExceptionLogger
{
  private const string HttpContextBaseKey = "MS_HttpContext";

  public override void Log(ExceptionLoggerContext context)
  {
    // Retrieve the current HttpContext instance for this request.
    HttpContext httpContext = GetHttpContext(context.Request);

    // Wrap the exception in an HttpUnhandledException so that ELMAH can capture the original error page.
    Exception exceptionToRaise = new HttpUnhandledException(message: null, innerException: context.Exception);

    ErrorSignal signal;
    if (httpContext == null)
    {
       signal = ErrorSignal.FromCurrentContext();
       // Send the exception to ELMAH (for logging, mailing, filtering, etc.).
       signal.Raise(exceptionToRaise);
    }
    else
    {
        signal = ErrorSignal.FromContext(httpContext);
        signal.Raise(exceptionToRaise);
    }
}

private static HttpContext GetHttpContext(HttpRequestMessage request)
{
    HttpContextBase contextBase = GetHttpContextBase(request);

    if (contextBase == null)
    {
        return null;
    }

    return ToHttpContext(contextBase);
}

private static HttpContextBase GetHttpContextBase(HttpRequestMessage request)
{
    if (request == null)
    {
        return null;
    }

    object value;

    if (!request.Properties.TryGetValue(HttpContextBaseKey, out value))
    {
        return null;
    }

    return value as HttpContextBase;
}

private static HttpContext ToHttpContext(HttpContextBase contextBase){return contextBase.ApplicationInstance.Context; } }

Register ElmahExceptionLogger class with Web API in startup.cs

config.Services.Add(typeof(IExceptionLogger), new ElmahExceptionLogger());

score 3 · Answer 2 · answered Aug 10 '16 at 12:33

Even though the answer by @Paresh works, you should use the Elmah.Contrib.WebApi package, since that includes everything needed to use ELMAH with Web API.

I've written a guide to install ELMAH with Web API. Basically you will install the ELMAH and Elmah.Contrib.WebApi packages and then configure it like this:

public static class WebApiConfig
{
    public static void Register(HttpConfiguration config)
    {
        ...
        config.Services.Add(typeof(IExceptionLogger), new ElmahExceptionLogger());
        ...
    }
}

Regarding the mail configuration, you can validate your web.config using the ELMAH Configuration Validator.

Implementing Elmah in web api project

2 Answers2