Why is the $_REQUEST array empty when sending JSON via Ajax?

S

sverhvova2018-11-11 21:01:57

PHP

sverhvova, 2018-11-11 21:01:57

I started learning php/ajax, I want to understand these subtleties when sending a post. If I send the body in urlencoded and multipart/form-data encoding, then in php $_REQUEST is filled with what is needed. But in the body I send the json string, then $_REQUEST is empty, but they are in $GLOBALS["HTTP_RAW_POST_DATA"] and " php://input ". Do I understand correctly that when sending json $_REQUEST will always be empty. If so, where is the best place to fetch data from $GLOBALS["HTTP_RAW_POST_DATA"] or " php://input ".

<!DOCTYPE html>
<html lang="ru">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <link rel="stylesheet" type="text/css" href="style.css">
  <title>Php</title>
</head>
<body>
  <div class="cont">
  <form method="POST" action="script.php">
    <input type="text" name="fname" value="Igor">
    <input type="text" name="lname" value="Ivanov">
    <input type="submit" name="send" value="send">
  </form>
  <div class="response">
    
  </div>
<script>
  var form = document.forms[0];
  var send = form.elements.send;
  send.addEventListener('click', function(e) {
    e.preventDefault();
    //var data = new FormData(form); // (1) все окей
    //var data = 'fname=Igor&lname=Ivanov'; // (2) тоже все ок
    //var data = "--random\r\nContent-Disposition: form-data; name='fname'\r\n\r\nIgor\r\n--random\r\nContent-Disposition: form-data; name='lname'\r\n\r\nIvanov\r\n--random--"; // (3) и тут норм
    var data = JSON.stringify({
      fname: 'Igor',
      lname: 'Ivanov'
    }); // (4)
    var xhr = new XMLHttpRequest;
    xhr.onreadystatechange = function() {
      if(xhr.readyState == 4 && xhr.status == 200) {
        var resp = xhr.responseText;
        console.log(resp);
        document.getElementsByClassName('response')[0].innerHTML = resp;
      }
    }
    xhr.open('POST', 'script.php', true);
    // xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded'); // (2)
    // xhr.setRequestHeader('Content-Type', 'multipart/form-data; boundary=random'); // (3)
    xhr.setRequestHeader('Content-Type', 'application/json; charset=utf-8'); // (4)
    xhr.send(data);
  });
</script>
</body>
</html>

<?php
echo '1)$_REQUEST ----- ';
echo var_dump($_REQUEST).'<br>';
echo '2)$GLOBALS[HTTP_RAW_POST_DATA] ----- ';
echo var_dump($GLOBALS["HTTP_RAW_POST_DATA"]).'<br>';
echo '3)php://input ----- ';
echo file_get_contents("php://input");
?>

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1 answer(s)

A

Antony Tkachenko, 2018-11-11
@sverhvova

php.net/manual/ru/reserved.variables.httprawpostda...
Deprecared, removed in 7.0+
Superglobal arrays $_GET, $_POST, $_REQUEST will only work when application/x-www-form-urlencoded or multipart/form- data in the Content-Type header of an HTTP request.
php.net/manual/en/reserved.variables.post.php
Use php://input