检查会话是否仍在运行的正确方法是什么？ 有哪些方法？

Question

So I have already had my first experience with Web Design, but there were some things I did in a certain way that I didn't like, mainly because of time. So anyway, I don't know which is the correct way to handle sessions. What I did in my previous project was to embed PHP into HTML and based on whatever was in $_SESSION, usually an id and a user type number, then I'd open or close parts of the website to the user, through embedded PHP.

However, this is not how I wanted to do this initially, at first what I wanted to do was to make a JavaScript code to send a request through AJAX to the server, and check if the session was still active, and based on that open/close parts of the website, but then I'd have to make a request on every page and every so often to make sure the user is logged in. Should I handle something like this client-side?

What are some other ways to check the session but without embedding PHP and using JavaScript instead to modify the HTML document.

Answer 1

To do this, all you need is an ajax request on loop and a php file to check the session.

The Javascript

function checkLogin(un) { //put this function in a loop of some sort depending on how you want to use it
  var xmlhttp = new XMLHttpRequest();
  xmlhttp.onreadystatechange = function() {
    if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
      logout(xmlhttp.responseText);
    }
  }
  xmlhttp.open("GET", "checklogin.php?un=" + un, true);
  xmlhttp.send();
}

function logout(resp) {
  if (resp == "false") { //comparing actual text, not boolean
    window.location.href = 'logout.php'; //destroy the session or something
  }
}

The PHP file checklogin.php (very simple)

<?php
if ($_SESSION[$_GET['un']] != true) {
  echo 'false';
}
?>

The php will depend on how you store your sessions, but in this case it is just using one session titled by their username that stores true if signed in. I would recommend making this more complex if you decide to actually use it.