Nuxt On Login mixin

onLoginMixin.ts

import { Component, Vue } from "vue-property-decorator";

const DEFAULT_REDIRECT = "home";
type redirectFn = () => string;

// You can declare a mixin as the same style as components.
@Component
export default class OnLoginMixin extends Vue {
  protected redirect?: string | redirectFn = DEFAULT_REDIRECT;
  protected watchLogin?: boolean = true;

  private $$cleanupLogin: () => void;

  public fetch() {
    this.checkLoggedIn();
  }

  public mounted() {
    this.checkLoggedIn();
    this.$$cleanupLogin = this.$auth.$storage.watchState(
      "loggedIn",
      this.checkLoggedIn.bind(this)
    );
  }

  public beforeDestroy() {
    this.$$cleanupLogin();
  }


  protected checkLoggedIn(...args) {
    if (this.$auth.loggedIn) {
      if (typeof this.redirect === "function") {
        this.redirect = this.redirect.call(this, args);
      }
      return this.$auth.redirect(typeof this.redirect === "string" ? this.redirect : DEFAULT_REDIRECT);
    }
  }

}