# pubsub-bus
[](https://github.com/an-dr/pubsub-bus/releases)
Thread-safe one-to-many event system. Simple and easy to use. It just works (hopefully).
Features:
- 📃 Event Topic Filtering
- 🔢 Unique event and publisher IDs
- 🔀 Thread-safe
- 🧱 No unsafe code
## Table of Contents
- [pubsub-bus](#pubsub-bus)
- [Table of Contents](#table-of-contents)
- [⚙️ What it does (Without words)](#️-what-it-does-without-words)
- [🚀 Quick Start](#-quick-start)
- [1. Add the dependency to your `Cargo.toml`](#1-add-the-dependency-to-your-cargotoml)
- [2. Create your events and a bus](#2-create-your-events-and-a-bus)
- [3. Implement the Subscriber trait for your struct and subscribe it to the bus](#3-implement-the-subscriber-trait-for-your-struct-and-subscribe-it-to-the-bus)
- [4. Create a Publisher and pass the bus to it](#4-create-a-publisher-and-pass-the-bus-to-it)
- [5. Send events](#5-send-events)
- [📖 Examples](#-examples)
## ⚙️ What it does (Without words)
## 🚀 Quick Start
### 1. Add the dependency to your `Cargo.toml`
```toml
pubsub-bus = "3.0.0"
```
### 2. Create your events and a bus
```rust
enum Commands {
Atack { player_id: u32 },
Move { player_id: u32, dx: f32, dy: f32 },
}
#[derive(PartialEq)]
enum TopicIds {
Player1,
Player2,
}
let bus: EventBus<Commands, TopicIds> = EventBus::new();
```
### 3. Implement the Subscriber trait for your struct and subscribe it to the bus
```rust
impl Subscriber<Commands, TopicIds> for Player {
fn on_event(&mut self, event: &BusEvent<Commands, TopicIds>) {
let event_id = event.get_id();
let event_source_id = event.get_source_id();
match event.get_content() {
...
}
}
}
...
let player1 = Player { id: 1 };
bus.add_subscriber(player1);
```
### 4. Create a Publisher and pass the bus to it
```rust
pub struct Input {
emitter: EventEmitter<Commands, TopicIds>,
}
impl Publisher<Commands, TopicIds> for Input {
fn get_mut_emitter(&mut self) -> &mut EventEmitter<Commands, TopicIds> {
&mut self.emitter
}
}
...
let mut input = Input::new();
bus.add_publisher(&mut input, None); // None -> Auto assign ID
```
### 5. Send events
```rust
input.publish( Commands::Move { dx: 1.0, dy: 2.0 },
Some(TopicIds::Player1) );
input.publish( Commands::Atack,
Some(TopicIds::Player2) );
```
## 📖 Examples
The following example demonstrates how to exchange events between players and an input system.
```rust
fn main() {
// Create a bus
let bus: EventBus<Commands, TopicIds> = EventBus::new();
// Create players, input, and attach to the bus
let player1 = Player { id: 1 };
let player2 = Player { id: 2 };
let mut input = Input::new();
bus.add_subscriber(player1);
bus.add_subscriber(player2);
bus.add_publisher(&mut input, Some(85)).unwrap();
// Send some events
input.publish(Commands::Move { dx: 1.0, dy: 2.0 },
Some(TopicIds::Player2));
input.publish(Commands::Move { dx: 1.0, dy: 2.0 },
Some(TopicIds::Player1));
input.publish(Commands::Atack, Some(TopicIds::Player2));
input.publish(Commands::Atack, Some(TopicIds::Player1));
}
```
For the full example, see the [examples/basic_game_events](examples/basic_game_events) directory.