readme.md

Meadow.Logging

Many good logging libraries already exist in the .NET development community, so why Meadow.Logging?

The primary driver is that Meadow is designed to run on microcontrollers, where storage and memory resources are limited. Most existing libraries provide a wide array of capabilties and features, but at the cost of size. Meadow.Logging is intended to be very, very lean, only exposing the minimal set of what might be needed by a typical Meadow application, but still completely usable in larger, non-Meadow application scenarios.

Contents

• Logger
• ILogProvider
• Usage
  • Basic usage
  • Using Multiple ILogProviders
  • Conditional Output Using LogLevel
  • Conditional Output Using Runtime Checks

Logger

The Logger class has two functions:

• Providing the methods an Application would typically call in order to add a log entry.
• Holding a collection of ILogProvider instances that will react to those methods.

ILogProvider

The ILogProvider interface provides the methods that the Logger will call when an Application makes a specific Logging call that meets the currently set Loglevel.

Two common implementations are inluded in the compiled library:

• ConsoleLogger outputs log information to System.Console
• DebugLogger outputs log information to System.Diagnostics.Debug

Since a primary goal of Meadow.Logging is to be small, some additional implementations (e.g. UDP broadcast logging or SQLIte logging) will likely be provided in source form until linking is fully supported by Meadow.

Usage

The general usage pattern is:

• Create a Logger instance
• Register one or more ILogProvider implementations
• Access the logger instance using a static, dependency injection, or whatever your preferred mechanism

Basic Usage

A simple example of Console output would look like this:

static void Main()
{
    var logger = new Logger(new ConsoleLogProvider());
    var App = new App(logger);

    app.DoStuff();
}

class App
{
    Logger Logger { get; init; }

    App(Logger logger)
    {
        Logger = logger;
    }

    public void DoStuff()
    {
        while(true)
        {
            Logger.Debug("tick");
            Thread.Sleep(1000);
        }
    }
}

Using Multiple ILogProviders

The Logger allows you to add 0:N ILogProvider instances, and all of them get called when ap application makes a logging call. For example, your application may want to output to both the Console and a UDP broadcast. You can achieve this by simply registering multiple providers:

var logger = new Logger();
logger.AddProvider(new ConsoleLogProvider());
logger.AddProvider(new UdpLogProvider());
...
logger.Info("This message will get delivered to all Providers");

Conditional Output Using LogLevel

Logger-wide output can be controlled using the LogLevel property. Log output will occur for any level at or above the currently set level.

var logger = new Logger(new ConsoleLogProvider());
...
logger.Loglevel = LogLevel.Debug;
logger.Debug("This debug message will get delivered to all Providers");
logger.Warn("This warning message will get delivered to all Providers");
...
logger.Loglevel = LogLevel.Info;
logger.Debug("This debug message will *not* get delivered to any Providers");
logger.Warn("This warning message will still get delivered to all Providers");

Conditional Output Using Runtime Checks

Occasionally you may want to keep a given log level, but output information based on a runtime check. All of the logging outputs support this as well.

var logger = new Logger(new ConsoleLogProvider());
bool logCondition = true;
...
logger.Debug("This debug message will get delivered to all Providers");
logger.Debug(logCondition, "This debug message will also get delivered to all Providers");
bool logCondition = false;
logger.Debug("This debug message will also get delivered to all Providers");
logger.Debug(logCondition, "This debug message will *not* get delivered to any Providers");