Function processCleanups

packages/core/src/render3/node_manipulation.ts:385–434

Removes listeners and unsubscribes from output subscriptions

(tView: TView, lView: LView)

/** Removes listeners and unsubscribes from output subscriptions */
function processCleanups(tView: TView, lView: LView): void {
  ngDevMode && assertNotReactive(processCleanups.name);
  const tCleanup = tView.cleanup;
  const lCleanup = lView[CLEANUP]!;
  if (tCleanup !== null) {
    for (let i = 0; i < tCleanup.length - 1; i += 2) {
      if (typeof tCleanup[i] === 'string') {
        // This is a native DOM listener. It will occupy 4 entries in the TCleanup array (hence i +=
        // 2 at the end of this block).
        const targetIdx = tCleanup[i + 3];
        ngDevMode && assertNumber(targetIdx, 'cleanup target must be a number');
        if (targetIdx >= 0) {
          // Destroy anything whose teardown is a function call (e.g. QueryList, ModelSignal).
          lCleanup[targetIdx]();
        } else {
          // Subscription
          lCleanup[-targetIdx].unsubscribe();
        }
        i += 2;
      } else {
        // This is a cleanup function that is grouped with the index of its context
        const context = lCleanup[tCleanup[i + 1]];
        tCleanup[i].call(context);
      }
    }
  }
  if (lCleanup !== null) {
    lView[CLEANUP] = null;
  }
  const destroyHooks = lView[ON_DESTROY_HOOKS];
  if (destroyHooks !== null) {
    // Reset the ON_DESTROY_HOOKS array before iterating over it to prevent hooks that unregister
    // themselves from mutating the array during iteration.
    lView[ON_DESTROY_HOOKS] = null;
    for (let i = 0; i < destroyHooks.length; i++) {
      const destroyHooksFn = destroyHooks[i];
      ngDevMode && assertFunction(destroyHooksFn, 'Expecting destroy hook to be a function.');
      destroyHooksFn();
    }
  }

  // Destroy effects registered to the view. Many of these will have been processed above.
  const effects = lView[EFFECTS];
  if (effects !== null) {
    lView[EFFECTS] = null;
    for (const effect of effects) {
      effect.destroy();
    }
  }
}

/** Calls onDestroy hooks for this view */
function executeOnDestroys(tView: TView, lView: LView): void {