Html 5 Form validation without Form

Question

Can a html5 form validation

Answer 1

Yes, use the constraint validation API. See http://www.w3.org/TR/html5/forms.html#the-constraint-validation-api. For instance, you can call element . checkValidity(). See also https://developer.mozilla.org/en-US/docs/Web/Guide/HTML/HTML5/Constraint_validation or https://developer.mozilla.org/en-US/docs/Web/API/HTMLSelectElement/checkValidity. For example:

var email = document.getElementById('email');
var valid = email . checkValidity();
if (!valid) ...

or use the invalid event which is fired when checkValidity() fails:

email.addEventListener("invalid", function() { alert("Email invalid"); });

You can use setCustomValidity to set the validity status and/or error message:

if (!email.value) email.setCustomValidity("Email is missing");