(function(){ 'use strict' // Example starter JavaScript for disabling form submissions if there are invalid fields // Fetch all the forms we want to apply custom Bootstrap validation styles to const forms = document.querySelectorAll('.needs-validation') /* Loop over them and prevent submission */ Array.from(forms).forEach(form => { form.addEventListener('submit', event => { if (!form.checkValidity()) { event.preventDefault() event.stopPropagation() } form.classList.add('was-validated') }, false) }) })();