Latency after first content update + no initial update message is sent

[lsliwaradioluz]

Describe the bug

1. When I update my content for the first time, the CONTENT_UPDATED message is sent after a significant delay (~5s). Subsequent updates work as expected.
2. When I have some content saved (and unpublished) and open Live Preview, Contentful does not send the initial CONTENT_UPDATED event to populate the iframe app with the saved and unpublished content.

To Reproduce
Steps to reproduce the behavior:

• Add the following lines to console.log messages received by your frontend rendered within iframe

window.addEventListener("message", (event) => {
  console.log(event.data.action);
});

• Open your content in a Live Preview window in Contentful dashboard,
• Edit your content and wait for the console.log to appear (see videos)

Expected behaviors
Message arrives immediately.

Screenshots / example
Delay:
https://github.com/contentful/live-preview/assets/39009379/c98aa0a6-0488-4393-903d-348bd6636b67

Missing first update message:
https://github.com/contentful/live-preview/assets/39009379/e839f83a-c9a0-41e0-9147-4e5892a90526

Context (please complete the following information):

• Live preview SDK version number: 3.3.1
• REST

Additional context
Our live preview usage. The data we pass is either a VueJS ref or React's useState state.

async function initLivePreview(
  data: ContentfulSubscribeConfig["data"] | null,
  livePreviewConfig?: LivePreviewConfig
) {
  if (typeof window === "undefined" || data == null) return;

  const CONTENTFUL_APP_URL = "https://app.contentful.com";
  const isInsideContentful =
    window.location.ancestorOrigins?.contains(CONTENTFUL_APP_URL) ?? false;
  const isWithinIframe = window.self !== window.top; /** Firefox fallback */
  const isLivePreview = isInsideContentful || isWithinIframe;

  if (!isLivePreview) return;

  const { ContentfulLivePreview } = await import("@contentful/live-preview");

  /** Default configs */
  const defaultConfig = {
    locale: "en-US",
    enableLiveUpdates: true,
    debugMode: false,
    enableInspectorMode: true,
    callback: (updatedData: ContentfulSubscribeConfig["data"]) => {
      Object.assign(data, updatedData);
    },
  };

  /** Merged configs */
  const {
    locale,
    enableLiveUpdates,
    debugMode,
    enableInspectorMode,
    callback,
  } = { ...defaultConfig, ...livePreviewConfig };

  if (!ContentfulLivePreview.initialized) {
    ContentfulLivePreview.init({
      locale,
      enableLiveUpdates,
      debugMode,
      enableInspectorMode,
    });
  }

  const unsubscribe = ContentfulLivePreview.subscribe({
    data,
    locale,
    callback,
  });

  return unsubscribe;
}

[YvesRijckaert]

Hi 👋 I am afraid that's intended behaviour. The auto-save event in Contentful currently saves every 5 seconds. We then sent over an event CONTENT_UPDATED so customers can react to this behaviour.
We are thinking of creating a better experience here (e.g. manual save trigger or reducing the seconds). But I can't communicate any timeline yet.

If you want immediate live updates then you can use the useLiveUpdates hook, then you don't have to wait for the save event.