PHP Contact Form 从 echo 打印混合输出

Question

我在网站上的联系表格有问题。一切正常，电子邮件到达没有任何问题，但它显示的输出如下：

基本上，它混淆了错误回显和成功输出...

php-联系表格：

<?php

// receive form submission data
$name = $_POST['name'];
$email = $_POST['email'];
$subject = $_POST['subject'];
$message = $_POST['message'];

// set the email details
$to = 'test';
$headers = "From: $email\r\n";
$headers .= "Reply-To: $email\r\n";

// send the email and check for errors
if (mail($to, $subject, $message, $headers)) {
    // email sent successfully
    echo "Email sent!";
} else {
    // email sending failed
    echo "Error: Unable to send email";
}
?>

contact.php:

<?php

  $receiving_email_address = 'test';

  if( file_exists($php_email_form = '../assets/vendor/php-email-form/php-email-form.php' )) {
    include( $php_email_form );
  } else {
    die( 'Unable to load the "PHP Email Form" Library!');
  }

  $contact = new PHP_Email_Form;
  $contact->ajax = true;
  
  $contact->to = $receiving_email_address;
  $contact->from_name = $_POST['name'];
  $contact->from_email = $_POST['email'];
  $contact->subject = $_POST['subject'];

  $contact->add_message( $_POST['name'], 'From');
  $contact->add_message( $_POST['email'], 'Email');
  $contact->add_message( $_POST['message'], 'Message', 10);

  echo $contact->send();
?>

index.html 最后一行联系表：

              <div class="my-3">
                <div class="loading">Loading</div>
                <div class="sent-message">Your message has been sent. Thank you!</div>
                <div class="error-message"></div>
                </div>
              <div class="text-center"><button type="submit">Send Message</button></div>

我尝试更改 PHP 中的回声，但没有任何效果。

这是 validate.js:

(function () {
  "use strict";

  let forms = document.querySelectorAll('.php-email-form');

  forms.forEach( function(e) {
    e.addEventListener('submit', function(event) {
      event.preventDefault();

      let thisForm = this;

      let action = thisForm.getAttribute('action');
      let recaptcha = thisForm.getAttribute('data-recaptcha-site-key');
      
      if( ! action ) {
        displayError(thisForm, 'The form action property is not set!')
        return;
      }
      thisForm.querySelector('.loading').classList.add('d-block');
      thisForm.querySelector('.error-message').classList.remove('d-block');
      thisForm.querySelector('.sent-message').classList.remove('d-block');

      let formData = new FormData( thisForm );

      if ( recaptcha ) {
        if(typeof grecaptcha !== "undefined" ) {
          grecaptcha.ready(function() {
            try {
              grecaptcha.execute(recaptcha, {action: 'php_email_form_submit'})
              .then(token => {
                formData.set('recaptcha-response', token);
                php_email_form_submit(thisForm, action, formData);
              })
            } catch(error) {
              displayError(thisForm, error)
            }
          });
        } else {
          displayError(thisForm, 'The reCaptcha javascript API url is not loaded!')
        }
      } else {
        php_email_form_submit(thisForm, action, formData);
      }
    });
  });

  function php_email_form_submit(thisForm, action, formData) {
    fetch(action, {
      method: 'POST',
      body: formData,
      headers: {'X-Requested-With': 'XMLHttpRequest'}
    })
    .then(response => {
      return response.text();
    })
    .then(data => {
      thisForm.querySelector('.loading').classList.remove('d-block');
      if (data.trim() == 'OK') {
        thisForm.querySelector('.sent-message').classList.add('d-block');
        thisForm.reset(); 
      } else {
        throw new Error(data ? data : 'Form submission failed and no error message returned from: ' + action); 
      }
    })
    .catch((error) => {
      displayError(thisForm, error);
    });
  }

  function displayError(thisForm, error) {
    thisForm.querySelector('.loading').classList.remove('d-block');
    thisForm.querySelector('.error-message').innerHTML = error;
    thisForm.querySelector('.error-message').classList.add('d-block');
  }

})();