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Hooks are a feature in React that allow you use state and other React features without writing classes. This website provides easy to understand code examples to help you learn how hooks work and inspire you to take advantage of them in your next project.

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Composes: useAuth, useRouter

A common need is a way to redirect the user if they are signed out and trying to view a page that should require them to be authenticated. This example shows how you can easily compose our useAuth and useRouter hooks to create a new useRequireAuth hook that does just that. Of course, this functionality could be added directly to our useAuth hook, but then we'd need to make that hook aware of our router logic. Using the power of hook composition we can keep the other two hooks as simple as possible and just utilize our new useRequireAuth when redirection is needed.

import Dashboard from "./Dashboard.js";
import Loading from "./Loading.js";
import { useRequireAuth } from "./use-require-auth.js";

function DashboardPage(props) {
  const auth = useRequireAuth();

  // If auth is null (still fetching data)
  // or false (logged out, above hook will redirect)
  // then show loading indicator.
  if (!auth) {
    return <Loading />;

  return <Dashboard auth={auth} />;

// Hook (use-require-auth.js)
import { useEffect } from "react";
import { useAuth } from "./use-auth.js";
import { useRouter } from "./use-router.js";

function useRequireAuth(redirectUrl = "/signup") {
  const auth = useAuth();
  const router = useRouter();

  // If auth.user is false that means we're not
  // logged in and should redirect.
  useEffect(() => {
    if (auth.user === false) {
  }, [auth, router]);

  return auth;
November 17, 2019
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