Change state of page(component) from another

For example i have a main page with login data = false.
how to change login state of main component from account page after successful login?
in another words, select ‘/’ route’s component from ‘/account/’ route for $setState() management?

actually there is a router refresh page but for some cases i cant use it,
it will be so good if there well be syntax like router.setState(’/’,{foo:bar},callback);

Use events to communicate between components