Ancestor Selection JS Helper Functions

get-ancestor-by-attribute.js

function getAncestorByAttribute(elem, attribute) {
  if (elem.parentElement === null) {
    return false;
  } else if (elem.hasAttribute(attribute)) {
    return elem;
  } else {
    return getAncestorByAttribute(elem.parentElement, attribute);
  }
}

get-ancestor-by-class.js

/**
 * Ancestor Selection Helpers
 */
function getAncestorByClass(elem, selector) {
  if (elem.parentElement === null) {
    return false;
  } else if (elem.classList.contains(selector)) {
    return elem;
  } else {
    return getAncestorByClass(elem.parentElement, selector);
  }
}

get-ancestor-by-tag.js

function getAncestorByTag(elem, tag) {
  if (elem.parentElement === null) {
    return false;
  } else if (elem.tagName.toLowerCase() === tag.toLowerCase()) {
    return elem;
  } else {
    return getAncestorByTag(elem.parentElement, tag);
  }
}