Waliduje poniższy formularz który teoretycznie działa ale w konsoli pojawia się błąd Uncaught TypeError: Cannot read property 'addEventListener' of null
at main.js. Czym to może być spowodowane?
// walidacja formularza customers
const fName = document.getElementById('first_name')
const bAdCustom = document.getElementById('addCustomer')
const pFirstName = document.querySelector('.requiredFirst')
const lastName = document.getElementById('last_name')
const pLastName = document.querySelector('.requiredLast')
const checkNames = () => {
if (!fName.value) {
pFirstName.style.color = 'red'
pFirstName.textContent = 'The first name field is required!'
fName.setCustomValidity('This field cannot be empty.');
}
else {
pFirstName.textContent = ''
}
if (fName.value != '' && !lastName.value) {
pLastName.style.color = 'red'
pLastName.textContent = 'The last name field is required!'
lastName.setCustomValidity('This field cannot be empty.');
} else {
pLastName.textContent = ''
}
}
fName.addEventListener('keyup', function () {
if (fName.value.length > 1) {
pFirstName.textContent = ''
fName.setCustomValidity('');
}
})
lastName.addEventListener('keyup', function () {
if (lastName.value.length > 1) {
pLastName.textContent = ''
lastName.setCustomValidity('')
}
})
bAdCustom.addEventListener('click', checkNames)