Opencart + SweetAlert + Ajax。为什么我无法捕获POST请求？

Question

我试图用3个输入（名称，电子邮件，文本）创建SweetAlert表单。提交后，此表单必须将表单数据发送到管理员电子邮件。我做到了，一切正常！但是我确定我的控制器代码无效。

CMS：OpenCart 2.3 + SweetAlert 2。

这是SweetAlert表单+ Ajax请求：

<script type="text/javascript">
  window.onload = function () {
    var a = document.getElementById('director');
    a.onclick = function() {
        Swal({
          type: 'warning',
          title: 'Your message',
          html:
            '<input name="name" id="swal-input1" class="swal2-input" placeholder="Your name">' +
            '<input name="email" id="swal-input2" class="swal2-input" placeholder="Email">' +
            '<textarea name="text" id="swal-textarea1" class="swal2-textarea" placeholder="Enter your text..." style="display: flex;"></textarea>',          
          showCancelButton: true,
          confirmButtonColor: '#ff5908',
          cancelButtonColor: '#666',
          confirmButtonText: 'Send',
          cancelButtonText: 'Cancel',
          preConfirm: function () {
            return new Promise(function (resolve) {
              resolve([
                $('#swal-input1').val(),
                $('#swal-input2').val(),
                $('#swal-textarea1').val()
              ])
            })
          },                    
        }).then(function (result) {
        	if (result.value) { 
		        var result = {};
		        result.name = $('#swal-input1').val();
		        result.email = $('#swal-input2').val(); 
		        result.text = $('#swal-textarea1').val(); 
		        var data = JSON.stringify(result);
	          	$.ajax({
	              url:"index.php?route=common/message/index",
	              type: "post",
                  data: data,                
                  dataType: "json",
	              success: function() {Swal({type: 'success', text: 'Message sent'});},
	              error: function(xhr,status,error){
	              console.log(status);
	              console.log(error);
	              }
	            })
        	}
        })

        return false;
    }
}
</script>

之后，ajax请求将发送到“ Message”控制器的“ index”方法。

<?php
class ControllerCommonMessage extends Controller {

		public function index() {

		$request_body = file_get_contents('php://input');
		$data = json_decode($request_body);

		$username = $data->name;
		$email = $data->email;
		$msg = $data->text;
  	    $subject = 'Test email from: '.$email;

		$mail = new Mail();

		$mail->protocol = $this->config->get('config_mail_protocol');
		$mail->parameter = $this->config->get('config_mail_parameter');
		$mail->smtp_hostname = $this->config->get('config_mail_smtp_hostname');
		$mail->smtp_username = $this->config->get('config_mail_smtp_username');
		$mail->smtp_password = html_entity_decode($this->config->get('config_mail_smtp_password'), ENT_QUOTES, 'UTF-8');
		$mail->smtp_port = $this->config->get('config_mail_smtp_port');
		$mail->smtp_timeout = $this->config->get('config_mail_smtp_timeout');

		$mail->setTo('mail@mail.com');
		$mail->setFrom($this->config->get('config_email'));
		$mail->setSender(html_entity_decode($this->config->get('config_name'), ENT_QUOTES, 'UTF-8'));
		$mail->setSubject(html_entity_decode($subject, ENT_QUOTES, 'UTF-8'));
		$mail->setHtml($msg);
		$mail->send();

    }			
}

因此，该表单正在运行，消息发送成功。但是，我不喜欢这段代码：

$request_body = file_get_contents('php://input');
$data = json_decode($request_body);

我也试图这样写：

if (isset($this->request->post['data'])) {
    $result = $this->request->post['data'];
    var_dump($result);
} else {
    echo 'empty';
}

但是没有任何效果。 “结果”为空。我在做什么错了？