webseite/assets/js/contact_form.js

const ajaxUrl = 'https://spielwiese.wtf-eg.de/php/contact_form.php';
// const submit_button = document.getElementsByClassName('contact_form__submit_button')[0];
const contact_form = document.getElementsByClassName('content__contact_form')[0];
const message = document.getElementsByClassName('contact_form__message')[0];
const name = document.getElementsByClassName('contact_form__name')[0];
const email = document.getElementsByClassName('contact_form__email')[0];
const captcha = document.getElementsByClassName('contact_form__captcha')[0];

contact_form.addEventListener('submit', function(event) {
    event.preventDefault();
    let formData = new FormData();
    formData.append('message', message.value);
    formData.append('name', name.value);
    formData.append('email', email.value);

    // If some bot entered some value, return.
    if (typeof captcha.value == 'undefined') {
        formData.append('captcha', 'Nudelsuppe');
    } else {
        console.log('bot detected');
        return;
    }

    fetch(ajaxUrl, {
        method: 'POST',
        mode:'same-origin',
        body: formData,
    })
    .then(response => response.json())
    .then(json => {console.log(json)});
}, false);