emitter

Emitter is an interface for broadcasting messages that can be received by other plugins.

configuration

This plugin does not support configuration.

remarks

This plugin is enabled by default and cannot be disabled.

api

pluginApi.emit(channel: string, ...rest: any[])

Notifies all registered listeners with the channel and any additional arguments.

params

• channel: string - The channel on which to broadcast the event.
• ...rest: any[] - Any additional arguments. These will be fanned out to all listeners.

returns

• Plugin - returns the plugin interface itself for fluent-style chaining.

jstag.on(topic: string, listener: Listener)

Subscribe to a topic by wildcard. The listener will be called for each matching event until it is manually unsubscribed.

params

• topic: string - The topic to subscribe to.
• listener: Listener - The listener to receive event notifications.

returns

• Subscription - An idempotent function encapsulating the capability to unsubscribe the listener from the topic. Calling this function will stop the listener from receiving notifications in the future.

examples

The next example adds a listener on the entity.loaded topic. Since the topic doesn't contain a wildcard star (*), only events with a topic matching the channel exactly will be delivered to the listener.

var unsubscribe = jstag.on("entity.loaded", function(channel, entity) {
  console.log(channel); // "entity.loaded"
  console.log(entity); // Entity { data: { ... } }
});

The next example adds a listener for all events by binding using the catch-all wildcard pattern *:

var unsubcribe = jstag.on("*", function(channel, param1, param2/*, ...and so on */) {
  console.log(channel); // The channel the event was broadcast on.
  console.log(param1); // The first argument
  console.log(param2); // The second argument
  // ...and so on
});

The next example adds a listener to all events broadcast in the google namespace:

var unsubscribe = jstag.on("google.*", function(channel) {
  console.log(channel); // The channel is guaranteed to start with "google."
});

The next example demonstrates unsubscribing:

var unsubscribe = jstag.on("*", function() {
  console.log("this will never be called");
});
unsubscribe(); // Synchronously unsubscribes our listener from the channel.
unsubscribe(); // Calling unsubscribe again has no effect.

jstag.once(topic: string, listener: Listener)

Subscribe to a topic by wildcard. The listener will be called at most one time. This is a convenience.

params

• topic: string - The topic to subscribe to.
• listener: Listener - The listener to receive event notifications.

returns

• Subscription - An idempotent function encapsulating the capability to unsubscribe the listener from the topic. Calling this function will stop the listener from receiving notifications in the future.

example

var unsubscribe = jstag.once("enitity.loaded", function(_, entity) {
  console.log(entity); // This will only happen once
});

jstag.loadEntity();

// ...sometime later
jstag.loadEntity();