Lime Web Components API Documentation - v6.24.0
    Preparing search index...

    Interface EventDispatcher

    Service for application-wide event communication

    The EventDispatcher enables loosely-coupled communication between components through a publish-subscribe pattern.

    Components can dispatch custom events and subscribe to events from other components without direct coupling. This is particularly useful for:

    • Cross-component communication
    • Responding to platform-level events (navigation, data changes)
    • Notifying other components of state changes

    Basic usage

    const eventDispatcher = platform.get(PlatformServiceName.EventDispatcher);

    // Dispatch an event
    eventDispatcher.dispatch('data-changed', { id: 123 });

    // Listen for events
    const handler = (event: CustomEvent<{ id: number }>) => {
        console.log('Data changed:', event.detail.id);
    };
    eventDispatcher.addListener('data-changed', handler);

    // Clean up
    eventDispatcher.removeListener('data-changed', handler);
    interface EventDispatcher {
        addListener<T>(
            eventName: string,
            listener: (event: CustomEvent<T>) => void,
        ): void;
        dispatch<T>(eventName: string, data: T): CustomEvent<T>;
        removeListener<T>(
            eventName: string,
            listener: (event: CustomEvent<T>) => void,
        ): void;
    }
    Index

    Methods

    addListener dispatch removeListener

    Methods

    • Register a listener for a specific event type

      The listener function will be called whenever an event with the matching name is dispatched. The same listener can be registered multiple times, but should typically be registered only once per component instance.

      Important: Always remove listeners in disconnectedCallback() to prevent memory leaks.

      Type Parameters

      • T

      Parameters

      • eventName: string

        Name of the event to listen for

      • listener: (event: CustomEvent<T>) => void

        Callback function to invoke when the event is dispatched

      Returns void

      eventDispatcher.addListener('message-received', (event) => {
          console.log('Message:', event.detail);
      });

    • Dispatch a custom event to all registered listeners

      Creates and dispatches a CustomEvent with the provided data. All components that have registered listeners for this event name will be notified.

      Type Parameters

      • T

      Parameters

      • eventName: string

        Unique name identifying the event type

      • data: T

        Data payload to include in the event's detail property

      Returns CustomEvent<T>

      The CustomEvent that was dispatched

      const eventDispatcher = platform.get(PlatformServiceName.EventDispatcher);
      eventDispatcher.dispatch('item-selected', { itemId: 42, name: 'Widget' });

    • Unregister a previously registered event listener

      Removes the specified listener function for the given event name. The listener reference must be the same function instance that was passed to addListener.

      Always call this in disconnectedCallback() to clean up listeners and prevent memory leaks.

      Type Parameters

      • T

      Parameters

      • eventName: string

        Name of the event to stop listening for

      • listener: (event: CustomEvent<T>) => void

        The exact listener function that was previously registered

      Returns void

      const handler = (event: CustomEvent<string>) => console.log(event.detail);
      eventDispatcher.addListener('message-received', handler);
      eventDispatcher.removeListener('message-received', handler);

    Settings

    Member Visibility

    On This Page

    Methods