Function annotateForHydration

packages/core/src/hydration/annotate.ts:243–301

(appRef: ApplicationRef, doc: Document)

 * @return event types that need to be replayed
 */
export function annotateForHydration(appRef: ApplicationRef, doc: Document) {
  const injector = appRef.injector;
  const isI18nHydrationEnabledVal = isI18nHydrationEnabled(injector);
  const isIncrementalHydrationEnabledVal = isIncrementalHydrationEnabled(injector);
  const serializedViewCollection = new SerializedViewCollection();
  const corruptedTextNodes = new Map<HTMLElement, TextNodeMarker>();
  const viewRefs = appRef._views;
  const shouldReplayEvents = injector.get(IS_EVENT_REPLAY_ENABLED, EVENT_REPLAY_ENABLED_DEFAULT);
  const eventTypesToReplay = {
    regular: new Set<string>(),
    capture: new Set<string>(),
  };
  const deferBlocks = new Map<string, SerializedDeferBlock>();
  const appId = appRef.injector.get(APP_ID);
  for (const viewRef of viewRefs) {
    const lNode = getLNodeForHydration(viewRef);

    // An `lView` might be `null` if a `ViewRef` represents
    // an embedded view (not a component view).
    if (lNode !== null) {
      const context: HydrationContext = {
        serializedViewCollection,
        corruptedTextNodes,
        isI18nHydrationEnabled: isI18nHydrationEnabledVal,
        isIncrementalHydrationEnabled: isIncrementalHydrationEnabledVal,
        i18nChildren: new Map(),
        eventTypesToReplay,
        shouldReplayEvents,
        appId,
        deferBlocks,
      };
      if (isLContainer(lNode)) {
        annotateLContainerForHydration(lNode, context);
      } else {
        annotateComponentLViewForHydration(lNode, context);
      }
      insertCorruptedTextNodeMarkers(corruptedTextNodes, doc);
    }
  }

  // Note: we *always* include hydration info key and a corresponding value
  // into the TransferState, even if the list of serialized views is empty.
  // This is needed as a signal to the client that the server part of the
  // hydration logic was setup and enabled correctly. Otherwise, if a client
  // hydration doesn't find a key in the transfer state - an error is produced.
  const serializedViews = serializedViewCollection.getAll();
  const transferState = injector.get(TransferState);
  transferState.set(NGH_DATA_KEY, serializedViews);

  if (deferBlocks.size > 0) {
    const blocks: {[key: string]: SerializedDeferBlock} = {};
    for (const [id, info] of deferBlocks.entries()) {
      blocks[id] = info;
    }
    transferState.set(NGH_DEFER_BLOCKS_KEY, blocks);
  }

  return eventTypesToReplay;