deliver.php
<?php
ini_set('display_errors',true);
error_reporting(E_ALL);
header('Access-Control-Allow-Origin: *');
header('Access-Control-Allow-Methods: GET, PUT, POST, DELETE, OPTIONS');
header('Access-Control-Max-Age: 1000');
header('Access-Control-Allow-Headers: Content-Type, Authorization, X-Requested-With');
$url = $_SERVER['REQUEST_URI'];
$url = parse_url($url, PHP_URL_PATH);
if ($url=='/save/'){
echo $_POST['marks'];
$json = $_POST['marks'];
$new = json_decode($json,true);
$existing = file_get_contents(__DIR__.'/marks.json');
$old = json_decode($existing,true);
$final = array_replace_recursive($old,$new);
$count = (count(scandir(__DIR__.'/old/'))-2);
if ($count>10)$count = 0;
rename(__DIR__.'/marks.json', __DIR__."/old/{$count}-marks.json");
file_put_contents(__DIR__.'/marks.json',json_encode($final,JSON_PRETTY_PRINT));
} else if ($url=='/load/'){
$json = file_get_contents(__DIR__.'/marks.json');
echo $json;
}