OutWit.Common.Reflection 1.1.0

OutWit.Common.Reflection

EventUtils: Universal Event Handling Made Easy

The EventUtils class provides utilities for working with .NET events, enabling developers to create universal handlers for any event in a highly reusable and reflective manner. This is particularly useful in scenarios requiring dynamic event handling or generalized solutions for complex event-driven architectures.

Features

1. Retrieve All Events of a Type

The GetAllEvents method recursively retrieves all events from a given type, including:

• Events defined on the type itself
• Events defined in its base types
• Events from implemented interfaces

Type type = typeof(SomeClass);
IEnumerable<EventInfo> allEvents = type.GetAllEvents();
foreach (var eventInfo in allEvents)
{
    Console.WriteLine(eventInfo.Name);
}

2. Create Universal Event Handlers

The CreateUniversalHandler method allows you to create a delegate for any event using a universal handler. This handler acts as a single entry point for all events of a type, dynamically handling event calls.

Key Benefits:

• Dynamically binds to event handlers at runtime.
• Enables centralized logging, debugging, or analytics for all events.
• Simplifies handling events with unknown signatures at compile-time.

Example Usage

using OutWit.Common.Reflection;

public class Example
{
    public static void Main()
    {
        var obj = new SomeClass();

        EventInfo eventInfo = typeof(SomeClass).GetEvent("SomeEvent")!;

        var handler = eventInfo.CreateUniversalHandler(
            obj,
            (sender, eventName, parameters) =>
            {
                Console.WriteLine($"Event {eventName} triggered on {sender} with parameters: {string.Join(", ", parameters)}");
            });

        eventInfo.AddEventHandler(obj, handler);

        obj.TriggerSomeEvent(); // Triggers the universal handler
    }
}

public class SomeClass
{
    public event EventHandler? SomeEvent;

    public void TriggerSomeEvent()
    {
        SomeEvent?.Invoke(this, EventArgs.Empty);
    }
}

Method Details

GetAllEvents

public static IEnumerable<EventInfo> GetAllEvents(this Type type)

• Description: Recursively retrieves all events from a type, including those from base types and interfaces.
• Returns: A collection of EventInfo objects.

CreateUniversalHandler

public static Delegate CreateUniversalHandler<TSender>(
    this EventInfo me,
    TSender sender,
    UniversalEventHandler<TSender> handler
) where TSender : class;

• Description: Creates a dynamic delegate that binds a universal handler to an event.
• Parameters:
  • me: The EventInfo describing the event.
  • sender: The object raising the event.
  • handler: The universal event handler delegate.
• Returns: A Delegate matching the event's signature.

UniversalEventHandler

A delegate used for the universal handler:

public delegate void UniversalEventHandler<in TSender>(
    TSender sender,
    string eventName,
    object[] parameters
) where TSender : class;

• Parameters:
  • sender: The object that raised the event.
  • eventName: The name of the event.
  • parameters: The event arguments passed during invocation.

Installation

Include the OutWit.Common.Reflection namespace in your project to access EventUtils.