EventDispatcher

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When to use

• Cross-system notifications (e.g. language changed, app initialized, session events) where publisher and subscriber live in different assemblies or scenes.
• String-keyed events with optional typed payloads — avoids coupling to concrete event classes.
• Prefer UnityEvent for Inspector-wired, single-object callbacks. Prefer C# event for tightly-coupled same-class patterns. Use EventDispatcher for everything else.

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TypedEvents

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Using from code

using UnityEngine;
using Molca;
using Molca.Events;

public class SessionStatusBanner : MonoBehaviour
{
    [SerializeField] private string status;

    [Inject] private EventDispatcher _eventDispatcher;

    private async void Start()
    {
        await RuntimeManager.WaitForInitialization();
        if (_eventDispatcher == null)
            RuntimeManager.InjectDependencies(this);
    }

    private void OnEnable()
    {
        if (_eventDispatcher == null) return;

        // Typed/event-constant style
        _eventDispatcher.RegisterEvent(EventConstants.Application.Initialized, OnAppInitialized);

        // Generic payload style
        _eventDispatcher.RegisterEvent<string>(EventConstants.UI.LanguageChanged, OnLanguageChanged);
    }

    private void OnDisable()
    {
        if (_eventDispatcher == null) return;
        _eventDispatcher.UnregisterEvent(EventConstants.Application.Initialized, OnAppInitialized);
        _eventDispatcher.UnregisterEvent<string>(EventConstants.UI.LanguageChanged, OnLanguageChanged);
    }

    public void MarkReady()
    {
        // Publish event to other systems
        _eventDispatcher?.DispatchEvent(EventConstants.Application.Initialized);
    }

    private void OnAppInitialized()
    {
        status = "Initialized";
    }

    private void OnLanguageChanged(string languageCode)
    {
        status = $"Language: {languageCode}";
    }
}

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API Reference

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Troubleshooting

• Event not received: confirm RegisterEvent runs before the first DispatchEvent. If subscription is in OnEnable but dispatch fires during RuntimeManager init, the handler may not be registered yet — move subscription to Start with await RuntimeManager.WaitForInitialization().
• Duplicate callbacks firing: calling RegisterEvent twice with the same callback adds it twice via Delegate.Combine. Always pair with UnregisterEvent in OnDisable to prevent stacking across enable/disable cycles.
• Missing unsubscribe causes errors after scene unload: destroyed objects’ callbacks remain registered and throw MissingReferenceException. Always call UnregisterEvent in OnDisable or OnDestroy.
• Wrong type parameter on DispatchEvent<T>: the type key must match exactly between publisher and subscriber. DispatchEvent<int> will not reach RegisterEvent<float> handlers even with the same event name.

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Related

• RuntimeManager — EventDispatcher is a RuntimeSubsystem on the prefab
• Dependency injection — use [Inject] to get the dispatcher
• Localization — dispatches via TypedEvents.LanguageChanged
• Recipe: Create and dispatch custom events — step-by-step guide to using EventDispatcher for decoupled communication