Set up logging with Blazor WebAssembly - asp.net-core

Question

I'm doing some experiments with Blazor and want to set up logging. I see that Blazor logs to Microsoft.Extensions.Logging out of the box and that the log messages go to the developer console inside the browser. That is a nice start.
Now I want to try and log messages to other destinations as well. It could be a cloud-service. I'm wondering where to set that up. In ASP.NET Core, you would set it up using the ConfigureLogging method in Program.cs. But this isn't available with Blazor:
public static IWebAssemblyHostBuilder CreateHostBuilder(string[] args) =>
BlazorWebAssemblyHost.CreateDefaultBuilder()
.UseBlazorStartup<Startup>()
.ConfigureLogging(...); // <- compile error
As a fallback, I'm trying to set it up through ConfigureServices in Startup.cs:
public void ConfigureServices(IServiceCollection services)
{
services.AddLogging(builder => builder
.AddMyLogger()
.SetMinimumLevel(LogLevel.Information));
}
with AddMyLogger:
public static ILoggingBuilder AddMyLogger(this ILoggingBuilder builder)
{
builder.Services.AddSingleton<ILoggerProvider, MyLoggerProvider>();
return builder;
}
and MyLoggerProvider:
public class MyLoggerProvider : ILoggerProvider
{
public ILogger CreateLogger(string categoryName)
{
return new MyLogger();
}
public void Dispose()
{
}
}
and MyLogger:
public class MyLogger : ILogger
{
public MyLogger()
{
}
public IDisposable BeginScope<TState>(TState state)
{
return null;
}
public bool IsEnabled(LogLevel logLevel)
{
return true;
}
public void Log<TState>(LogLevel logLevel, EventId eventId, TState state, Exception exception, Func<TState, Exception, string> formatter)
{
}
}
The AddMyLogger-method is called but my logger is never created or receives any Log-calls.
Am I doing something wrong here or is logging with Blazor WebAssembly simply not ready yet?

Answer 1

I was trying something similar. In my case, the Log method in MyLogger gets called; however it fails at following line of code
using (var streamWriter = new StreamWriter(fullFilePath, true)) //Fails here
{
streamWriter.WriteLine(logRecord);
}
When I put it in try catch block, I got the exception "Children could not be evaluated".
While researching I came across following link. Steve Sanderson's response might make sense of the behavior
Reading local files #16156
BTW It's been a long time, please let me know the solution you came up with.