Function getDeclarationTNode

packages/core/src/render3/state.ts:542–560

* Returns a `TNode` of the location where the current `LView` is declared at. * * @param lView an `LView` that we want to find parent `TNode` for.

(lView: LView)

 * @param lView an `LView` that we want to find parent `TNode` for.
 */
function getDeclarationTNode(lView: LView): TNode | null {
  const tView = lView[TVIEW];

  // Return the declaration parent for embedded views
  if (tView.type === TViewType.Embedded) {
    ngDevMode && assertDefined(tView.declTNode, 'Embedded TNodes should have declaration parents.');
    return tView.declTNode;
  }

  // Components don't have `TView.declTNode` because each instance of component could be
  // inserted in different location, hence `TView.declTNode` is meaningless.
  // Falling back to `T_HOST` in case we cross component boundary.
  if (tView.type === TViewType.Component) {
    return lView[T_HOST];
  }

  // Remaining TNode type is `TViewType.Root` which doesn't have a parent TNode.
  return null;
}

/**
 * This is a light weight version of the `enterView` which is needed by the DI system.