Function createNode

packages/router/src/create_router_state.ts:35–68

(
  routeReuseStrategy: RouteReuseStrategy,
  curr: TreeNode<ActivatedRouteSnapshot>,
  prevState: TreeNode<ActivatedRoute> | undefined,
  newlyCreatedRoutes: Set<ActivatedRoute>,
)

}

function createNode(
  routeReuseStrategy: RouteReuseStrategy,
  curr: TreeNode<ActivatedRouteSnapshot>,
  prevState: TreeNode<ActivatedRoute> | undefined,
  newlyCreatedRoutes: Set<ActivatedRoute>,
): TreeNode<ActivatedRoute> {
  // reuse an activated route that is currently displayed on the screen
  if (prevState && routeReuseStrategy.shouldReuseRoute(curr.value, prevState.value.snapshot)) {
    const value = prevState.value;
    value._futureSnapshot = curr.value;
    const children = createOrReuseChildren(routeReuseStrategy, curr, prevState, newlyCreatedRoutes);
    return new TreeNode<ActivatedRoute>(value, children);
  } else {
    if (routeReuseStrategy.shouldAttach(curr.value)) {
      // retrieve an activated route that is used to be displayed, but is not currently displayed
      const detachedRouteHandle = routeReuseStrategy.retrieve(curr.value);
      if (detachedRouteHandle !== null) {
        const tree = (detachedRouteHandle as DetachedRouteHandleInternal).route;
        tree.value._futureSnapshot = curr.value;
        tree.children = curr.children.map((c) =>
          createNode(routeReuseStrategy, c, undefined, newlyCreatedRoutes),
        );
        return tree;
      }
    }

    const value = createActivatedRoute(curr.value);
    newlyCreatedRoutes.add(value);
    const children = curr.children.map((c) =>
      createNode(routeReuseStrategy, c, undefined, newlyCreatedRoutes),
    );
    return new TreeNode<ActivatedRoute>(value, children);
  }
}

function createOrReuseChildren(
  routeReuseStrategy: RouteReuseStrategy,