gistfile1.js

function getArticleById() {
  return new Promise(function(resolve, reject) {
  // Ambil nilai query parameter (?id=)
  var urlParams = new URLSearchParams(window.location.search);
  var idParam = urlParams.get("id");

    if ('caches' in window) {
      caches.match(base_url + "article/"+idParam).then(function(response) {
        if (response) {
          response.json().then(function (data) {
                        ...
                        ...
                        ...
document.getElementById("articles").innerHTML = articlesHTML;
            resolve(data);

          })
        }
      })
    }



  fetch(base_url + "article/" + idParam)
    .then(status)
    .then(json)
    .then(function(data) {
                        ...
                        ...
                        ...
      document.getElementById("body-content").innerHTML = articleHTML;
      resolve(data);
    })
  })
};