为什么我的php代码在ajax执行时无法执行

好的，我试图将我的网站进行ajax化，并且在首页上出现一个重大问题，即使用原始ajax并使用responseText，最重要的是，有一棵文件树被用于使用某些功能

首先是问题文件代码

<?php
echo 'apple'; // this runs


// is not returning or executing this
include('../core/init.php');


echo 'apple'; // this does not run

if(!empty($_POST)){

$validate = new validate();
if(token::check(input::get('token'))) {
    $validation = $validate->check($_POST, array(
        'title' => array(
            'required' => true
        ),
        'message' => array(
            'required' => true
        ),
    ));

    if ($validation->passed()) {
        #create the post
        $db_instance = DB::getInstance();
        #check the value of private before submitting as there is an error there
        $private = 0;
        if(isset($_POST['private'])){
            $private = 1;
        }

        if(@$db_instance->insert('feed',array(
            'user_id'   =>  $user->data()->id,
            'title'     =>  $_POST['title'],
            'message'   =>  $_POST['message'],
            'private'   =>  $private
        ))){
            echo'updated the site activity';
        }
    }else{
        foreach ($validation->errors() as $error) {
            echo '<br>';
            echo $error, '<br>';
        }
        echo '<br>';
    }
}
}else{

   echo '<p>error</p>';
}
?>

继续此文件位于包含树中，例如index->​​ updateFeed-> ajaxScript（已运行）-> thiscode

如果任何人都可以在没有jquery的情况下使用类似的结构进行解释，那出了什么问题id会很有意义

<?php
// lets us redirect using headers even if headers have already been sent out
ob_start();

session_start();

error_reporting(1);
// config
$GLOBALS['config'] = array(

'mysql' => array(
    'host'      => 'XXXXXXXXXXXXX',
    'username'  => 'XXXXXXXXXXXXX',
    'password'  => 'XXXXXXXXXXXXX',
    'db'        => 'XXXXXXXXXXXXX'
),


'remember' => array(
    'cookie_name'   => 'wpd_remember_cookie',
    'cookie_expiry' => 2628000
),
'session' => array(
    'session_name'  => 'user',
    'token_name'    => 'CSRF_token'
)
);

// auto-load classes
spl_autoload_register(function($class){
    require_once ('classes/' . $class . '.php');
});

require_once ('functions/sanitize.php');
require('functions/Gravatar.php');          //used for the gravatar
require('functions/email_verify.php');


//check if the user is logged in by tokens and if not don't log the user in other wise log them in

if(cookie::exists(config::get('remember/cookie_name')) && !session::exists(config::get('session/session_name'))){
    $hash = cookie::get(config::get('remember/cookie_name'));
    $hashCheck = DB::getInstance()->get('users_session', array('hash', '=', $hash ));

    if($hashCheck->count()){
        $user = new user ($hashCheck->first()->user_id);
        $user->login();
    }
}
?>