Function applyToElementOrContainer

packages/core/src/render3/node_manipulation.ts:110–179

* NOTE: for performance reasons, the possible actions are inlined within the function instead of * being passed as an argument.

(
  action: WalkTNodeTreeAction,
  renderer: Renderer,
  injector: Injector,
  parent: RElement | null,
  lNodeToHandle: RNode | LContainer | LView,
  tNode: TNode,
  beforeNode?: RNode | null,
  parentLView?: LView,
)

 * being passed as an argument.
 */
function applyToElementOrContainer(
  action: WalkTNodeTreeAction,
  renderer: Renderer,
  injector: Injector,
  parent: RElement | null,
  lNodeToHandle: RNode | LContainer | LView,
  tNode: TNode,
  beforeNode?: RNode | null,
  parentLView?: LView,
) {
  // If this slot was allocated for a text node dynamically created by i18n, the text node itself
  // won't be created until i18nApply() in the update block, so this node should be skipped.
  // For more info, see "ICU expressions should work inside an ngTemplateOutlet inside an ngFor"
  // in `i18n_spec.ts`.
  if (lNodeToHandle != null) {
    let lContainer: LContainer | undefined;
    let isComponent = false;
    // We are expecting an RNode, but in the case of a component or LContainer the `RNode` is
    // wrapped in an array which needs to be unwrapped. We need to know if it is a component and if
    // it has LContainer so that we can process all of those cases appropriately.
    if (isLContainer(lNodeToHandle)) {
      lContainer = lNodeToHandle;
    } else if (isLView(lNodeToHandle)) {
      isComponent = true;
      ngDevMode && assertDefined(lNodeToHandle[HOST], 'HOST must be defined for a component LView');
      lNodeToHandle = lNodeToHandle[HOST]!;
    }
    const rNode: RNode = unwrapRNode(lNodeToHandle);
    if (action === WalkTNodeTreeAction.Create && parent !== null) {
      maybeQueueEnterAnimation(parentLView, parent, tNode, injector);
      if (beforeNode == null) {
        nativeAppendChild(renderer, parent, rNode);
      } else {
        nativeInsertBefore(renderer, parent, rNode, beforeNode || null, true);
      }
    } else if (action === WalkTNodeTreeAction.Insert && parent !== null) {
      maybeQueueEnterAnimation(parentLView, parent, tNode, injector);
      nativeInsertBefore(renderer, parent, rNode, beforeNode || null, true);
      cancelLeavingNodes(tNode, rNode as HTMLElement, parentLView);
    } else if (action === WalkTNodeTreeAction.Detach) {
      if (parentLView?.[ANIMATIONS]?.leave?.has(tNode.index)) {
        trackLeavingNodes(tNode, rNode as HTMLElement, parentLView);
      }
      reusedNodes.delete(rNode as HTMLElement);
      runLeaveAnimationsWithCallback(
        parentLView,
        tNode,
        injector,
        (nodeHasLeaveAnimations: boolean) => {
          if (reusedNodes.has(rNode as HTMLElement)) {
            reusedNodes.delete(rNode as HTMLElement);
            return;
          }
          // the nodeHasLeaveAnimations indicates to the renderer that the element needs to
          // be removed synchronously and sets the requireSynchronousElementRemoval flag in
          // the renderer.
          nativeRemoveNode(renderer, rNode, isComponent, nodeHasLeaveAnimations);
        },