Function processAndInitTriggers

packages/core/src/defer/triggering.ts:655–700

(
  injector: Injector,
  blockData: Map<string, BlockSummary>,
  nodes: Map<string, Comment>,
)

 * properly initialized
 */
export function processAndInitTriggers(
  injector: Injector,
  blockData: Map<string, BlockSummary>,
  nodes: Map<string, Comment>,
) {
  const idleElements: ElementTrigger[] = [];
  const timerElements: ElementTrigger[] = [];
  const viewportElements: ElementTrigger[] = [];
  const immediateElements: ElementTrigger[] = [];
  for (let [blockId, blockSummary] of blockData) {
    const commentNode = nodes.get(blockId);
    if (commentNode !== undefined) {
      const numRootNodes = blockSummary.data[NUM_ROOT_NODES];
      let currentNode: Comment | HTMLElement = commentNode;
      for (let i = 0; i < numRootNodes; i++) {
        currentNode = currentNode.previousSibling as HTMLElement;
        if (currentNode.nodeType !== Node.ELEMENT_NODE) {
          continue;
        }
        const elementTrigger: ElementTrigger = {el: currentNode, blockName: blockId};
        // hydrate
        if (blockSummary.hydrate.idle) {
          idleElements.push(elementTrigger);
        }
        if (blockSummary.hydrate.immediate) {
          immediateElements.push(elementTrigger);
        }
        if (blockSummary.hydrate.timer !== null) {
          elementTrigger.delay = blockSummary.hydrate.timer;
          timerElements.push(elementTrigger);
        }
        if (blockSummary.hydrate.viewport) {
          if (typeof blockSummary.hydrate.viewport !== 'boolean') {
            elementTrigger.intersectionObserverOptions = blockSummary.hydrate.viewport;
          }
          viewportElements.push(elementTrigger);
        }
      }
    }
  }

  setIdleTriggers(injector, idleElements);
  setImmediateTriggers(injector, immediateElements);
  setViewportTriggers(injector, viewportElements);
  setTimerTriggers(injector, timerElements);
}

function setIdleTriggers(injector: Injector, elementTriggers: ElementTrigger[]) {
  for (const elementTrigger of elementTriggers) {