会话在 joomla 中不起作用

情况是这样的：有2个材料：regis和profil，有一个连接到regis的ajax脚本，有一个通过ajax发送到saveUser.php的表单处理程序。如果您使用以下代码，那么一切都会正常运行（所有检查都有效，一切都已保存，它会从 regis 切换到 profil）。

注册：

<div id="result_form"> </div>
<form id="reg_form" class="form" action="" method="POST">
<div class="form-group"><label>Ваш логин для входа на сайт:</label><br /> <input class="form-control" maxlength="50" name="login" type="text" placeholder="Your login..." data-validate="" /><span class="hint">Обязательно для заполнения</span></div>
<div class="form-group"><label>Ваш пароль:</label><br /> <input class="form-control" maxlength="50" name="password" type="password" placeholder="Your pASS..." data-validate="" /><span class="hint">Обязательно для заполнения</span></div>
<div class="form-group"><label>Ваша должность:</label><br /> <input class="form-control" maxlength="50" name="position" type="text" placeholder="Your position..." data-validate="" /><span class="hint">Обязательно для заполнения</span></div>
<div class="form-group"><label>Ваше место работы:</label><br /> <input class="form-control" maxlength="50" name="placeJob" type="text" placeholder="Your place job..." data-validate="" /><span class="hint">Обязательно для заполнения</span></div>

<div class="form-group"><input id="reg_btn" class="btn btn-primary" name="submit" type="submit" value="Зарегистрироваться" /></div></form>

profile - 这里应该通过 sourcerer 插件从会话中输出一个值

{source} <?php
echo("Hello");
?> {/source}

阿贾克斯：

$( document ).ready(function() {
    $("#reg_btn").click(
        function(ev){
          ev.preventDefault();
          var forma = $("#reg_form");
          var field = [];
          var leng = 0;
          forma.find('input[data-validate]').each(function() {
            field.push('input[data-validate]');
            var value = $(this).val();
            var line = $(this).closest('.form-group');
              if(!value){
                line.addClass('emptyField');
                setTimeout(function() {
                  line.removeClass('emptyField')
                }.bind(this),3000);
              }else{leng++;}            
          });
          if(leng == field.length){
            sendAjaxForm('result_form', 'reg_form', 'http://ip/nameSite/templates/bootstrap4/dopScripts/saveUser.php');
            return false;            
          }
        }
    );
});

function sendAjaxForm(result_form, reg_form, url) {
    $.ajax({
        url:     url, 
        type:     "POST", 
        dataType: "html", //формат данных
        data: $("#"+reg_form).serialize(),  
        success: function(response) { 
          result = $.parseJSON(response);
          if(result.already == "True"){
            var message = document.getElementById('result_form');
            message.innerHTML = "<p style='color: red;'>Такой логин уже существует</p>";            
            message.scrollIntoView();
          }else{
            window.location.href = 'moj-profil';            
          }
        },
        error: function(response) {
            $('#result_form').html('Ошибка. Данные не отправлены.');
        }
    });
}

保存用户.php：

<?php
  if (isset($_POST['login'])) { $login = $_POST['login']; if ($login == '') { unset($login);} }
  if (isset($_POST['password'])) { $password = $_POST['password']; if ($password =='') { unset($password);} }
  if (isset($_POST['position'])) { $position = $_POST['position']; if ($position =='') { unset($position);}}
  if (isset($_POST['placeJob'])) { $placejob = $_POST['placeJob']; if ($placejob =='') { unset($placejob);}}  
  include('bd.php');
  $checkUser="SELECT nick FROM registration WHERE nick = ?";
  $query = $db->prepare($checkUser);
  $query->bind_param("s", $login);
  $query->execute();
  $query->store_result();
  $query->bind_result($check_email);
  $query->fetch();
  $empty = $query->num_rows();
  if($empty != 0){
    $already="True";
    $result = array('already'=>$already);
  }else{
    $insert = "INSERT INTO registration (nick, pass, position, placejob)VALUES (?, ?, ?, ?)";
    $qinsert = $db->prepare($insert);
    $qinsert->bind_param("ssss", $login, $password, $position, $placejob);
    $qinsert->execute();
    $already="False";
    //THIS PLACE 
    $result = array(
        'already' => $already,
        'login' => $login
    );
  }
  echo json_encode($result);
?>

现在的问题。很多资料表明，session_start(); $_SESSION['']jooml 中的常规构造会话不起作用，应使用以下构造：

报名参加会议

define( '_JEXEC', 1 );
define('JPATH_BASE', $_SERVER['DOCUMENT_ROOT']);
define( 'DS', DIRECTORY_SEPARATOR );
require_once (JPATH_BASE . DS . 'includes' . DS . 'defines.php');
require_once (JPATH_BASE . DS . 'includes' . DS . 'framework.php');
$mainframe = JFactory::getApplication('site');
$mainframe->initialise();
$mainframe = JFactory::getApplication('site');
$session = JFactory::getSession();
$session->set('myVar', array('login'=>$login, 'first'=>1));

要获得会话：

{source} <?php
define( '_JEXEC', 1 );
define('JPATH_BASE', $_SERVER['DOCUMENT_ROOT']);
define( 'DS', DIRECTORY_SEPARATOR );
require_once (JPATH_BASE . DS . 'includes' . DS . 'defines.php');
require_once (JPATH_BASE . DS . 'includes' . DS . 'framework.php');
$mainframe = JFactory::getApplication('site');
$mainframe->initialise();
$session = JFactory::getSession();
$mySess = $session->get('myVar', array());
echo("Hello $mySess");//Результат Hello Array
foreach($mySess as $one){
echo("Hello".$one['login']." ".$one['first']);//Результат пуст
}
?> {/source}

但它不起作用，因为如果会话入口代码插入//THIS PLACE到 saveUser.php 文件或任何其他地方，那么所有内容都将写入数据库，但 ajax 不会重定向到新页面并会说Uncaught SyntaxError: Unexpected end in JSON，如果使用defined('_JEXEC') or die;或Uncaught SyntaxError: Unexpected token < in JSON，如果使用define('_JEXEC', 1);。 我是joomle的新手，不太了解。您能告诉我如何修复此错误，以便会话正常连接、保存和工作吗？