Lifecycle

MAF offers a set of lifecycle hooks that allow you to run code at specific points in the lifecycle of a room. These hooks can be used to perform tasks such as initialization, loading data, cleaning up resources, and more.

The background Hook

Allows you to run code in the background, outside of being triggered by a client or some other event. This is useful for tasks that need to run continuously or on a schedule, such as polling an external API, performing background computations, or sending periodic updates to clients.

use maf::prelude::*;

struct Timer {
    counter: u32,
}

impl StoreData for Timer {
    type Select<'this> = u32;

    fn init() -> Self {
        Timer { counter: 0 }
    }

    fn name() -> impl AsRef<str> + Send {
        "timer"
    }

    fn select(&self, _user: &User) -> Self::Select<'_> {
        self.counter
    }
}

// A simple background task that increments the counter in the Timer store every
// second. Note that the background task can take any parameters you want, and
// MAF will automatically inject the appropriate values when the task is run.
async fn increment_counter(store: Store<Timer>) {
    loop {
        tasks::sleep(std::time::Duration::from_secs(1)).await;

        store.write().await.counter += 1;
        println!("incremented counter!");
    }
}

// In your MAF app's main function, you can use the `background` hook to run a
// background task that increments the timer every second.
fn build() -> App {
    App::builder()
        .store::<Timer>()
        .background(increment_counter)
        .build()
}

maf::register!(build);

The init Hook

This hook is called when a room is first created. It allows you to perform any initialization tasks, such as setting up initial state, loading data from a API, or configuring the room's settings. The init hook is called once when the room is created and is called before any clients are connected to the room.

use maf::prelude::*;

fn generate_key() -> String { /* ... */ }

fn init(app: App) {
    // app.add_key() is a method that allows your room to get another room key
    // at runtime.
    app.add_key(generate_key()).expect("failed to add key");
}

fn build() -> App {
    App::builder()
        .init(init)
        .build()
}

maf::register!(build);