Using ElmahCore

ELMAH for ASP.NET Core

Add nuget package elmahcore

Simple usage

Startup.cs

1)	services.AddElmah() in ConfigureServices 
2)	app.UseElmah(); in Configure

Default elmah path ~/elmah.

Change URL path

services.AddElmah(options => option.Path = "you_path_here")

Restrict access to the Elmah url

services.AddElmah(options =>
{
        options.CheckPermissionAction = context => context.User.Identity.IsAuthenticated;
});

Change Error Log type

You can create your own error log, which will store errors anywhere.

    class MyErrorLog: ErrorLog
    //implement ErrorLog

This ErrorLogs available in board:

• MemoryErrorLog – store errors in memory (by default)
• XmlFileErrorLog – store errors in XML files
• SqlErrorLog - store errors in MS SQL (add reference to ElmahCore.Sql)

services.AddElmah<XmlFileErrorLog>(options =>
{
    options.LogPath = "~/log"; // OR options.LogPath = "с:\errors";
});

services.AddElmah<SqlErrorLog>(options =>
{
    options.ConnectionString = "connection_string"; // DB structure see here: https://bitbucket.org/project-elmah/main/downloads/ELMAH-1.2-db-SQLServer.sql
});

Rise exception

public IActionResult Test()
{
    HttpContext.RiseError(new InvalidOperationException("Test"));
    ...
}

Using Notifiers

You can create your own notifiers by implement IErrorNotifier interface and add notifier to Elmah options:

services.AddElmah<XmlFileErrorLog>(options =>
{
    options.Path = @"errors";
    options.LogPath = "~/logs";
    options.Notifiers.Add(new ErrorMailNotifier("Email",emailOptions));
});

Each notifier must have unique name.

Using Filters

You can use Elmah XML filter configuration in separate file, create and add custom filters:

services.AddElmah<XmlFileErrorLog>(options =>
{
    options.FiltersConfig = "elmah.xml";
    options.Filters.Add(new MyFilter());
})

Custom filter must implement IErrorFilter. XML filter config example:

<?xml version="1.0" encoding="utf-8" ?>
<elmah>
	<errorFilter>
		<notifiers>
			<notifier name="Email"/>
		</notifiers>
		<test>
			<and>
				<greater binding="HttpStatusCode" value="399" type="Int32" />
				<lesser  binding="HttpStatusCode" value="500" type="Int32" />
			</and> 
		</test>
	</errorFilter>
</elmah>

see more here

JavaScript filters not yet impemented :(

Add notifiers to errorFilter node if you do not want to send notifications Filtered errors will be logged, but will not be sent.