Thread-safe generic event library for C++ (17+)
Tip
Please read this document before using the library. I know, you don't have time but reading this document will save you time. I mean just this file, it's not long at all. Trial and error will cost you more time.
- What is this library used for?
- How to add it to my project
- How to use?
- Semantic Versioning
- License
- Contact
C++ standard library does not include a ready to use Event Handling mechanism. This library is designed to work as a singleton throughout the application and to communicate thread-safely between different code blocks via the required events with its generic structure.
With the Event Hub library, you can add or remove new listeners to the events, as you are used to in other languages, listen to a single event or all events from one place and emit them with the required type of data.
This is a header only library with no external dependency. So actually, all you need is to add the libcpp-event-hub.hpp file in src folder to your project and start using it with #include.
You can find usage examples in the examples folder, also find a sample CMakeLists.txt file content below.
cmake_minimum_required(VERSION 3.14)
project(myProject)
add_executable(myProject main.cpp libcpp-event-hub.hpp)
You can find a simple example of adding & deleting event listeners and emitting events to handle different types of them below.
#include "libcpp-event-hub.hpp"
#include <string>
#include <iostream>
using namespace lklibs;
int main()
{
// Get the singleton instance of the EventHub
auto& eventHub = EventHub::getInstance();
// Add a listener for testEvent1, which sends a string value
auto listener1Id = eventHub.addListener<std::string>("testEvent1", [](const std::string& eventName, const std::string& sender, const std::string& data)
{
std::cout << "1. listener received, Event name: " << eventName << ", sender: " << sender << ", data: " << data << std::endl;
});
// Add a listener for testEvent2, which sends an int value
auto listener2Id = eventHub.addListener<int>("testEvent2", [](const std::string& eventName, const std::string& sender, const int& data)
{
std::cout << "2 listener received, Event name: " << eventName << ", sender: " << sender << ", data: " << data << std::endl;
});
// Add a general listener for all events with a string value
auto listener3Id = eventHub.addListener<std::string>("*", [](const std::string& eventName, const std::string& sender, const std::string& data)
{
std::cout << "General listener received: " << eventName << ", sender: " << sender << ", data: " << data << std::endl;
});
// Emit testEvent1 with a string value, 2 listeners will receive the event (listener1 and the general listener)
eventHub.emit("testEvent1", "main", std::string("Value 1"));
// Emit testEvent2 with an int value, 1 listeners will receive the event (listener2), because there is no general listener for int values
eventHub.emit("testEvent2", "main", 7);
// Remove the first listener for testEvent1
eventHub.removeListener("testEvent1", listener1Id);
// Emit testEvent1 again, only the general listener will receive the event
eventHub.emit("testEvent1", "main", std::string("Value 2"));
return 0;
}Versioning of the library is done using conventional semantic versioning. Accordingly, in the versioning made as MAJOR.MINOR.PATCH;
PATCH: Includes possible Bug&Fixes and improvements. You definitely want to get this.
MINOR: Additional functionality added via backwards compatibility. You probably want to get this, it doesn't hurt.
MAJOR: Additional functionality that breaks backwards compatibility. You'll need to know what's changed before you get it, and you'll probably have to make changes to your own code. If I publish something like this, I will definitely add the changes required for migration section to the documentation.
MIT License
Copyright (c) 2024 Levent KARAGÖL
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
If you have problems regarding the library, please open an issue on GitHub. Please describe your request, issue, or question in as much detail as possible and also include the version of your compiler and operating system, as well as the version of the library you are using. Before opening a new issue, please confirm that the topic is not already exists in closed issues.