SubscriptionChannel

The SubscriptionChannel class is used to send messages from the backend to the frontend, using the same mechanism used by live queries.

example:

// Defined in code that is shared between the frontend and the backend
const statusChange = new SubscriptionChannel<{ oldStatus: number, newStatus: number }>("statusChange");

// Backend: Publishing a message
statusChange.publish({ oldStatus: 1, newStatus: 2 });

// Frontend: Subscribing to messages
statusChange.subscribe((message) => {
    console.log(`Status changed from ${message.oldStatus} to ${message.newStatus}`);
});

// Note: If you want to publish from the frontend, use a BackendMethod for that.

constructor

Constructs a new SubscriptionChannel instance.

Arguments:

• channelKey - The key that identifies the channel.

channelKey

The key that identifies the channel.

publish

Publishes a message to the channel. This method should only be used on the backend.

Arguments:

• message - The message to be published.
• remult - An optional instance of Remult to use for publishing the message.

subscribe

Subscribes to messages from the channel. This method should only be used on the frontend.

returns:

A promise that resolves to a function that can be used to unsubscribe from the channel.

Arguments:

• next - A function that will be called with each message received.
• remult - An optional instance of Remult to use for the subscription.