FGV.Lib.Log.ElmahCore 1.1.0

FGV.Lib.Log.ElmahCore

A comprehensive error logging library for .NET applications that wraps and extends ElmahCore functionality. This library provides a simplified interface for logging errors to a SQL Server database, along with useful extensions and filters.

Overview

FGV.Lib.Log.ElmahCore is designed to streamline error logging in .NET applications by providing:

• Simple integration with ASP.NET Core applications
• SQL Server error storage
• Customizable error filtering
• Easy-to-use logging interface
• Error enrichment capabilities

Installation

Add the FGV.Lib.Log.ElmahCore package to your project:

dotnet add package FGV.Lib.Log.ElmahCore

Setup

1. Register Services

In your Program.cs or Startup.cs file, add the following:

using FGV.Lib.Log.ElmahCore.Extensions;

// In ConfigureServices method:
services.AddElmahCore(options =>
{
    options.ConnectionString = Configuration.GetConnectionString("DefaultConnection");
    options.Path = "/elmah"; // Optional: defaults to "/elmah"
    options.LogPath = "~/logs"; // Optional: for local log files if needed
});

// In Configure method:
app.UseElmahCore();

2. Configure Dependency Injection

using FGV.Lib.Log.ElmahCore;
using FGV.Lib.Log.ElmahCore.Interfaces;

// Register the logger
services.AddScoped<ICustomLogger, Logger>();

Usage

Basic Error Logging

public class ExampleService
{
    private readonly ICustomLogger _logger;

    public ExampleService(ICustomLogger logger)
    {
        _logger = logger;
    }

    public void DoSomething()
    {
        try
        {
            // Your code here
        }
        catch (Exception ex)
        {
            // Log the error
            _logger.LogError(ex, "Error occurred in ExampleService.DoSomething");
        }
    }
}

Enriching Error Logs with Additional Data

try
{
    // Your code here
}
catch (Exception ex)
{
    // Log the error with additional context
    _logger.LogError(ex, "Error processing user data", new
    {
        UserId = "123",
        Operation = "DataUpdate",
        Timestamp = DateTime.UtcNow
    });
}

Manual Error Logging

// Log an error without an exception
_logger.LogMessage("Warning: System approaching memory limits", "MemoryWarning");

// Create and log a custom exception
var customException = new InvalidOperationException("Invalid state detected");
_logger.LogError(customException, "System state error");

Configuration Options

Database Connection

In appsettings.json:

{
"ConnectionStrings": {
    "DefaultConnection": "Server=yourserver;Database=YourDb;User Id=username;Password=password;"
}
}

Error Filtering

By default, the library filters out some common errors:

• NotFound (404) errors
• MethodNotAllowed (405) errors

You can customize the filters by modifying the ElmahFilters.cs file or extending it with your own filters.

Custom Database Setup

If you need to manually initialize the error log database table:

using FGV.Lib.Log.ElmahCore.Helpers;

// Create the error log table
ElmahErrorLog.CreateLogTable(connectionString);

Viewing Logs

Access the Elmah error log dashboard at /elmah (or your custom path) in your application to view logged errors.

Advanced Usage

Implementing Custom Loggers

You can create your own custom logger by implementing the ICustomLogger interface:

public class MyCustomLogger : ICustomLogger
{
    public void LogError(Exception exception, string message, object additionalInfo = null)
    {
        // Your implementation here
    }

    public void LogMessage(string message, string source)
    {
        // Your implementation here
    }
}

License

This project is licensed under the MIT License - see the LICENSE file for details.