Function getUUID

packages/foliate-js/epub.js:595–601

(opf)

const isUUID = /([0-9a-f]{8})-([0-9a-f]{4})-([0-9a-f]{4})-([0-9a-f]{4})-([0-9a-f]{12})/;

const getUUID = (opf) => {
  for (const el of opf.getElementsByTagNameNS(NS.DC, "identifier")) {
    const [id] = getElementText(el).split(":").slice(-1);
    if (isUUID.test(id)) return id;
  }
  return "";
};

const getIdentifier = (opf) =>
  getElementText(