为什么我的 $_SESSION 变量消失了？答案

【问题标题】：Why is my $_SESSION variable disappearing?为什么我的 $_SESSION 变量消失了？
【发布时间】：2016-02-15 14:52:39
【问题描述】：

我有一个功能

$capdir = get_template_directory_uri() . '/assets/captcha/';
$capmap = array(
    'cat' => $capdir . 'Captcha_Cat.png',
    'dog'  => $capdir . 'Captcha_Dog.png',
    'fish' => $capdir . 'Captcha_Fish.png'
);

function set_animal_captcha ( )
{
    global $capmap;
    // returns image url of random animal and stores in session storage
    // a reference to that animal
    $randAnimal = array_rand($capmap, 1);
    $_SESSION['animal'] = $randAnimal;
    die($capmap[$randAnimal]);
}

在页面加载时触发并且我已经确认它正在成功运行。然后我有一个函数

add_action('wp_ajax_nopriv_contact', 'contact');
add_action('wp_ajax_contact', 'contact');

// $nameMap is a map of input names to table cells in the email
// e.g. <input name="email" value="myemail@gmail.com"/> gets made into the row <tr><td><b>Email Address:<b></td><td>myemail@gmail.com</td></tr>
// by the mapping 'email' => 'Email Address' in the array 
$nameMap = array(
    'name' => 'Name', 
    'email' => 'Email Address', 
    'phone' => 'Phone Number', 
    'comments' => 'Stuff in text box'
);

// https://css-tricks.com/sending-nice-html-email-with-php/
$headers = "MIME-Version: 1.0\r\nContent-Type: text/html; charset=ISO-8859-1\r\n"; 
function contact ( )
{
    global $nameMap, $headers;

    $info = array(
        // name good as long as its not empty
        'validName' => (strlen(trim($_POST['name'])) > 0 ? true : false), 
        // http://stackoverflow.com/questions/201323/using-a-regular-expression-to-validate-an-email-address            
        // http://stackoverflow.com/questions/123559/a-comprehensive-regex-for-phone-number-validation
        'validEmail' => (preg_match("!^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$!", trim($_POST['email'])) == 1 ? true : false), 
        'validPhoneNumber' => (preg_match("!^(?:(?:\+?1\s*(?:[.-]\s*)?)?(?:\(\s*([2-9]1[02-9]|[2-9][02-8]1|[2-9][02-8][02-9])\s*\)|([2-9]1[02-9]|[2-9][02-8]1|[2-9][02-8][02-9]))\s*(?:[.-]\s*)?)?([2-9]1[02-9]|[2-9][02-9]1|[2-9][02-9]{2})\s*(?:[.-]\s*)?([0-9]{4})(?:\s*(?:#|x\.?|ext\.?|extension)\s*(\d+))?$!",trim($_POST['phone'])) == 1 ? true : false), 
        // if answer to captch equals animal in session storage
        'correctAnimal' => ($_SESSION['animal'] === trim(strtolower($_POST['capanswer']))) 
    );
    // see http://stackoverflow.com/questions/482377/php-regex-delimiter-whats-the-point about why "!" is around the regexes
    if (!$info['validName'] || !$info['validEmail'] || !$info['validPhoneNumber'] || !$info['correctAnimal'] ) // if invalid name, email or phone number
    {
        $info['sentEmail'] = false;
    } else {
        // inputs contained valid values
        // contstruct email body
        $emailMsg = '<html><body><h3>Someone submitted a contact form ...</h3><table>';
        foreach ($_POST as $key => $value) if (array_key_exists($key, $nameMap)) $emailMsg .= '<tr><td><b>' . $nameMap[$key] . ':</b></td><td>' . $value . '</td></tr>';
        $emailMsg .= '</table></body></html>';

        // attempt to send email and set 'sentEmail' key accordingly
        $info['sentEmail'] = mail("myemail@gmail.com", "A Comment Was Submitted",$emailMsg,$headers) ? true : false;
    }

    echo json_encode($info); 
    die();
}

在页面上提交表单时触发，但我发现

$_SESSION['animal']

在触发该函数时未定义。这可能是什么原因。

（哦，是的，如您所见，我总是将引用 Stack Overflow 的帖子注释掉，然后将它们复制粘贴到生产代码中哈哈）

【问题讨论】：

你在任何地方都给session_start打电话吗？
是的，在顶部做一个session_start();。
php.net/manual/en/function.error-reporting.php
@andrewsi 在我的页面标题中我有` if (session_status() == PHP_SESSION_NONE) { session_start(); }`

标签： php http session post server

【解决方案1】：

我要检查的第一件事是客户端上是否禁用了 cookie。

如果没有 cookie，我相信会话将驻留在服务器的内存中，以便在初始请求时完整执行脚本 - 然后在发出下一页请求之前消失。

你的整个 $_SESSION 是消失了，还是只是“动物”？

【讨论】：

我刚刚验证了调用函数时还有其他会话变量