Form-Submit and Download at the Same Time

<button 
	type="submit"
	class="w-100 btn btn-dark rounded-0"
	data-download="/download/file.pdf">
	Button-Text
</button>

window.addEventListener("load", () => {
    const fid = "#download-form";
    const cr_form = document.querySelector(fid);
    const cr_submitForm = document.querySelector(fid + " button[type=submit]");
    if (cr_form != null) cr_form.addEventListener("submit", function(e) {
        /* intercept submit: */
        e.preventDefault();
        /* Prepare a cheated auto-download: */
        var element = document.createElement('a');
        element.href = cr_submitForm.dataset.download;
        /* regex, to have just the filename: */
        element.download = /[^/]*$/.exec(cr_submitForm.dataset.download)[0];
        cr_form.appendChild(element);
        /* imitate a click: */
        element.click();
        /* and tidy up afterwards: */
        cr_form.removeChild(element);
        /* execute actual submit (via form post/get): */
        $(this).submit();
    })
});