CODE EXAMPLE FOR JAVASCRIPT

decode jwt

import { JwtHelperService } from "@auth0/angular-jwt";

constructor(private jwtHelper: JwtHelperService) {}

// DDECODIFICA TOKEN
CheckUser(): void {
  	this.role = this.GetUserRole();
	this.username = this.GetUsername();
	const token = this.tokenGetter();
	if (token && this.jwtHelper.isTokenExpired(token)) {
  		alert("Sessione scaduta!");
  		this.router.navigate(["login"]);
      	return;
	}
	if (token && !this.jwtHelper.isTokenExpired(token)) {
  		this.isLogged = true;
  		if (this.role === "User") {
    		this.adminMode = false;
  		} else {
    		this.adminMode = true;
  		}	
    }
	console.log("logged?: " + this.isLogged);
	console.log("role: " + this.role);
	console.log("username: " + this.username);
	console.log("adminMode?: " + this.adminMode);
}

tokenGetter() {
  	return localStorage.getItem("token");
}

GetUserRole() {
    const token = this.tokenGetter();
    if (!token) {
      return;
    }
    let tokenData = this.jwtHelper.decodeToken(token);
    let role =
        tokenData[
          "http://schemas.microsoft.com/ws/2008/06/identity/claims/role"
        ];
    return role;
}

GetUsername() {
    const token = this.tokenGetter();
    if (!token) {
      return;
    }
    let tokenData = this.jwtHelper.decodeToken(token);
    let username =
        tokenData[
          "http://schemas.xmlsoap.org/ws/2005/05/identity/claims/name"
        ];
    return username;
}