#119 - Age Calculator From Date Input v0.1

<!-- 💙 MEMBERSCRIPT #119 v0.1 💙 - AGE CALCULATOR FROM DATE INPUT -->
<script>
  // Function to calculate age
  function calculateAge(birthDate) {
    const today = new Date();
    const birth = new Date(birthDate);
    let age = today.getFullYear() - birth.getFullYear();
    const monthDiff = today.getMonth() - birth.getMonth();

    if (monthDiff < 0 || (monthDiff === 0 && today.getDate() < birth.getDate())) {
      age--;
    }

    return age;
  }

  // Function to update age input
  function updateAgeInput(birthdayInput) {
    const attrValue = birthdayInput.getAttribute('ms-code-bday-input');
    const ageInput = document.querySelector(`[ms-code-age-input="${attrValue}"]`);

    if (birthdayInput.value) {
      const age = calculateAge(birthdayInput.value);
      ageInput.value = age;
    } else {
      ageInput.value = '';
    }
  }

  // Function to set up event listeners for all birthday inputs
  function setupAgeCalculators() {
    const birthdayInputs = document.querySelectorAll('[ms-code-bday-input]');

    birthdayInputs.forEach(input => {
      input.addEventListener('input', () => updateAgeInput(input));
      // Initial call to set age if birthday is pre-filled
      updateAgeInput(input);
    });
  }

  // Run setup when the DOM is fully loaded
  document.addEventListener('DOMContentLoaded', setupAgeCalculators);
</script>