Lime Web Components API Documentation - v7.4.0
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    Interface Poller<T>Beta

    A generic interface for a poller that periodically executes a callback and notifies subscribers of the result. The poller manages its lifecycle automatically, ensuring that polling starts when the first subscriber registers and stops when the last subscriber unsubscribes.

    The poller caches the most recent value from the callback and immediately delivers it to any new subscriber without waiting for the next polling cycle.

    Common use cases:

    • Fetching real-time data updates (notifications, status changes)
    • Monitoring background tasks or long-running operations
    • Auto-refreshing dashboards and metrics
    • Syncing state with server-side changes
    import {
        PlatformServiceName,
        createLogger,
    } from '@limetech/lime-web-components';

    const logger = createLogger('my-component');
    const http = platform.get(PlatformServiceName.Http);

    const poller = platform
        .get(PlatformServiceName.PollerFactory)
        .create((): Promise<number> => http.get('my_addon/unread_count'), 60_000);

    const unsubscribe = poller.subscribe((unreadCount) => {
        logger.debug('Received data', { unreadCount });
    });

    // Later, clean up
    unsubscribe();
    interface Poller<T> {
        subscribe(callback: (value?: T) => void): () => void;
        trigger(): void;
    }

    Type Parameters

    • T
    Index

    Methods

    subscribe trigger

    Methods

    • Beta

      Subscribes a callback to receive updates from the poller.

      A new subscriber immediately receives the latest cached value, and all subscribers are notified of subsequent polling results.

      The subscription is active until the returned unsubscribe function is called. Unsubscribe during component cleanup (disconnectedCallback) to prevent memory leaks and unnecessary polling when the component is removed from the DOM.

      Parameters

      • callback: (value?: T) => void

        A function that will be called with the latest value from the poller callback. If no value is available yet, the callback will receive undefined. The callback is invoked:

        • Immediately upon subscription (with cached value or undefined)
        • After each successful poll cycle
        • When trigger is called manually

      Returns () => void

      A function to unsubscribe from the poller. Call this function to stop receiving updates and clean up the subscription.

      import { State } from '@stencil/core';
      import {
          LimeWebComponentPlatform,
          PlatformServiceName,
      } from '@limetech/lime-web-components';

      class MyComponent {
          public platform: LimeWebComponentPlatform;

          @State()
          private taskCount: number;

          private unsubscribe: () => void;

          public connectedCallback() {
              const http = this.platform.get(PlatformServiceName.Http);
              const poller = this.platform
                  .get(PlatformServiceName.PollerFactory)
                  .create(
                      (): Promise<number> => http.get('my_addon/task_count'),
                      30_000
                  );

              this.unsubscribe = poller.subscribe((taskCount) => {
                  this.taskCount = taskCount ?? 0;
              });
          }

          public disconnectedCallback() {
              this.unsubscribe();
          }
      }
    • Beta

      Immediately forces the poller to execute its callback.

      This method triggers an out-of-band poll, resetting the internal timer so that the next regular poll happens at the full interval from now. The trigger happens asynchronously, and all subscribers are notified with the result once the poll completes.

      Useful for:

      • Implementing manual refresh buttons
      • Forcing an update after a user action
      • Ensuring fresh data before a critical operation

      Returns void

      import { PlatformServiceName } from '@limetech/lime-web-components';

      const http = platform.get(PlatformServiceName.Http);

      const poller = platform
          .get(PlatformServiceName.PollerFactory)
          .create(() => http.get('my_addon/import_status'), 60_000);

      // Refresh now instead of waiting for the next interval
      poller.trigger();

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