PHP 定义在 XMLHttpRequest() 之后不起作用

Question

I need to protect a file using PHP constant variable and access files only through index.php. I need to get this page through XMLHttpRequest request but when I send page.php's content inside index.php's page-container DIV using Javascript's XMLHttpRequest it does not work and always redirects to homepage.

I have 4 files in the same folder

1. index.php
2. page.php
3. get-page.js
4. protectedf.php

index.php code

<?php define("protectedf", TRUE); ?>

<div class="page-container"></div>

page.php code

<?php require_once("protectedf.php"); ob_start(); ?>
// some html inside page.php

get-page.js code

const pageContainer = document.querySelector('.page-container');
function mySettings(){ 
        const x   = new XMLHttpRequest();
        const url = 'page.php';
        x.open('GET',url);
        x.send();
        x.addEventListener('readystatechange',function(){
            if (this.readyState == 4 && this.status == 200) {
                const xResult = this.responseText;
                pageContainer.innerHTML = xResult;
                this.abort();
            }
        });
}

protectedf.php code

<?php
    if (!defined("protectedf")) {
        header("Location:http://localhost/homepage/");
        exit();
    }
?>

Answer 1

just add define("protectedf", TRUE); on the page that include it: page.php