Foundation 6 Abide cleanup with named attributes and dataset interfaces

details.js

// check if form element has attributes using getNamedItem() on the attributes interface
if (trailerDetailsFormSection['type'].attributes.getNamedItem('required')) {
  // remove named attribute also using the attributes interface via removeNamedItem();
  trailerDetailsFormSection['type'].attributes.removeNamedItem('required');
}

// ... and is equivalent to running
// see https://lists.w3.org/Archives/Public/www-dom/2001JanMar/0094.html for explanation
trailerDetailsFormSection['type'].removeAttribute('required');

namedAttributesDataset.js

  /**
   * @param el
   */
  function cleanupFoundationAbideAttributes(el) {
    // cleanup element (which appears as `data-invalid` in DOM)
    if (el.dataset.invalid === '') {
      delete el.dataset.invalid;
    }
    
    // cleanup element (alternate method)
    if (el.attributes.getNamedItem('data-invalid')) {
      el.attributes.removeNamedItem('data-invalid');
    }

    // cleanup input
    if (el.classList.contains('is-invalid-input')) {
      el.classList.remove('is-invalid-input');
    }

    // cleanup label
    if (el.parentNode.classList.contains('is-invalid-label')) {
      el.parentNode.classList.remove('is-invalid-input');
    }
  }