提交表单时显示图像加载的纯 javascript 代码（仅中心图像）

Question

I've searched everywhere both on stackoverflow and on the web. surely it will be so trivial as not to be reported however focusing on the backend I would really need it. Specifically, I would need a pure javascript function to show after form submission (therefore only if the required fields are inserted) and show as a single image in the center and with a white background while waiting for the backend to do the redirects. thank you very much and happy new year

Answer 1

this is the solution i created after reading some javascript basic book. In fact it was simple but like all things it must first be studied. I leave it as it will certainly be useful to someone

    <script type="text/javascript">
const form = document.getElementById('generationLinkForm');
const loadingLottie = document.getElementById('loadingLottie');

    form.addEventListener('submit', (e) => {
        var value = document.getElementById('inputLink').value;
        const preloader = document.querySelector('.link-loading');
        if (value.length > 0) {
              form.classList.toggle('fade-out');
              loadingLottie.classList.toggle('show');
              preloader.classList.remove('d-none');
             }
        else
            e.preventDefault();
         
        });
</script>