server::EventBus Class Reference

Type-safe event bus for the server. More...

#include <EventBus.hpp>

Inheritance diagram for server::EventBus:

Collaboration diagram for server::EventBus:

Public Types
template<typename T >
using	EventCallback = std::function< void(const T &)>
	Callback type for an event.

Public Member Functions
	EventBus ()=default
	~EventBus () override=default
template<typename T >
void	subscribe (EventCallback< T > callback)
	Subscribe to an event type.
template<typename T >
void	publish (const T &event)
	Publish an event.
void	clear () override
	Clear all subscriptions.
Public Member Functions inherited from server::IEventBus
virtual	~IEventBus ()=default

Private Attributes
std::unordered_map< std::type_index, std::vector< std::function< void(const std::any &)> > >	_subscribers
	Container of subscribers per event type.

Detailed Description

Type-safe event bus for the server.

EventBus allows different components of the server to communicate via events without introducing direct dependencies. Each event type T can have multiple subscribers (callbacks) that are invoked when the event is published.

Subscribers are stored in a container keyed by typeid(T) and called in the order they were registered.

Example usage:

Server::EventBus bus;
bus.subscribe<MyEvent>([](const MyEvent &e){ std::cout << e.value << std::endl; });
MyEvent evt{42};
bus.publish(evt);

Definition at line 38 of file EventBus.hpp.

Member Typedef Documentation

EventCallback

template<typename T >

using server::EventBus::EventCallback = std::function<void(const T &)>

Callback type for an event.

Template Parameters

T	Event type

EventCallback is a function taking a const reference to an event. It will be called whenever the corresponding event type is published.

Definition at line 51 of file EventBus.hpp.

Constructor & Destructor Documentation

EventBus()

server::EventBus::EventBus ( )

default

~EventBus()

server::EventBus::~EventBus ( )

overridedefault

Member Function Documentation

clear()

void server::EventBus::clear ( )

inlineoverridevirtual

Clear all subscriptions.

Completely clears the event bus, removing all subscribers for all event types.

Implements server::IEventBus.

Definition at line 96 of file EventBus.hpp.

References _subscribers.

publish()

template<typename T >

void server::EventBus::publish ( const T &  event )

inline

Publish an event.

Template Parameters

T	Event type

Parameters

event

Event instance to publish

Invokes all subscribers for type T with the provided event. If no subscribers exist, the function does nothing.

Definition at line 80 of file EventBus.hpp.

References _subscribers.

subscribe()

template<typename T >

void server::EventBus::subscribe ( EventCallback< T >  callback )

inline

Subscribe to an event type.

Template Parameters

T	Event type

Parameters

callback

Function to call when an event of type T is published

Adds the callback to the list of subscribers for type T. Callbacks are stored using type-erasure with std::any. The wrapper converts std::any back to T before invoking user callbacks.

Definition at line 63 of file EventBus.hpp.

References _subscribers.

Member Data Documentation

_subscribers

std::unordered_map<std::type_index, std::vector<std::function<void(const std::any &)> > > server::EventBus::_subscribers

private

Container of subscribers per event type.

Each event type T is identified by typeid(T). Callbacks are stored using type-erasure (std::function<void(const std::any &)>), allowing multiple types to coexist in the same bus.

Definition at line 106 of file EventBus.hpp.

Referenced by clear(), publish(), and subscribe().

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The documentation for this class was generated from the following file:

• server/Core/EventBus/EventBus.hpp