ElmahCore 2.1.2

This project is licensed under the terms of the Apache license 2.0.

Using ElmahCore

ELMAH for Net.Standard and Net.Core (3.1, 5, 6)

Add nuget package elmahcore

Simple usage

Startup.cs

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

app.UseElmah() must be after initializing other exception handling middleware, such as (UseExceptionHandler, UseDeveloperExceptionPage, etc.)

Default elmah path ~/elmah.

Change URL path

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

Restrict access to the Elmah url

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

Note: app.UseElmah(); needs to be after

app.UseAuthentication();
app.UseAuthorization();
app.UseElmah();

or the user will be redirected to the sign in screen even if he is authenticated.

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)
• MysqlErrorLog - store errors in MySQL (add reference to ElmahCore.MySql)
• PgsqlErrorLog - store errors in PostgreSQL (add reference to ElmahCore.Postgresql)

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

services.AddElmah<SqlErrorLog>(options =>
{
 options.ConnectionString = "connection_string";
 options.SqlServerDatabaseSchemaName = "Errors"; //Defaults to dbo if not set
 options.SqlServerDatabaseTableName = "ElmahError"; //Defaults to ELMAH_Error if not set
});

Raise exception

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

Microsoft.Extensions.Logging support

Since version 2.0 ElmahCore support Microsoft.Extensions.Logging

Source Preview

Since version 2.0.1 ElmahCore support source preview. Just add paths to source files.

services.AddElmah(options =>
{
 options.SourcePaths = new []
 {
 @"D:\tmp\ElmahCore.DemoCore3",
 @"D:\tmp\ElmahCore.Mvc",
 @"D:\tmp\ElmahCore"
 };
});

Log the request body

Since version 2.0.5 ElmahCore can log the request body.

Logging SQL request body

Since version 2.0.6 ElmahCore can log the SQL request body.

Logging method parameters

Since version 2.0.6 ElmahCore can log method parameters.

using ElmahCore;
...

public void TestMethod(string p1, int p2)
{
 // Logging method parameters
 this.LogParams((nameof(p1), p1), (nameof(p2), p2));
 ...
}

Using UseElmahExceptionPage

You can replace UseDeveloperExceptionPage to UseElmahExceptionPage

if (env.IsDevelopment())
{
 //app.UseDeveloperExceptionPage();
 app.UseElmahExceptionPage();
}

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.