devdocs/assets/javascripts/templates/pages/offline_tmpl.js

app.templates.offlinePage = (docs) => `\
<h1 class="_lined-heading">Offline Documentation</h1>

<div class="_docs-tools">
  <label>
    <input type="checkbox" name="autoUpdate" value="1" ${
      app.settings.get("manualUpdate") ? "" : "checked"
    }>Install updates automatically
  </label>
  <div class="_docs-links">
    <button type="button" class="_btn-link" data-action-all="install">Install all</button><button type="button" class="_btn-link" data-action-all="update"><strong>Update all</strong></button><button type="button" class="_btn-link" data-action-all="uninstall">Uninstall all</button>
  </div>
</div>

<div class="_table">
  <table class="_docs">
    <tr>
      <th>Documentation</th>
      <th class="_docs-size">Size</th>
      <th>Status</th>
      <th>Action</th>
    </tr>
    ${docs}
  </table>
</div>
<p class="_note"><strong>Note:</strong> your browser may delete DevDocs's offline data if your computer is running low on disk space and you haven't used the app in a while. Load this page before going offline to make sure the data is still there.
<h2 class="_block-heading">Questions & Answers</h2>
<dl>
  <dt>How does this work?
  <dd>Each page is cached as a key-value pair in <a href="https://devdocs.io/dom/indexeddb_api">IndexedDB</a> (downloaded from a single file).<br>
      The app also uses <a href="https://devdocs.io/dom/service_worker_api/using_service_workers">Service Workers</a> and <a href="https://devdocs.io/dom/web_storage_api">localStorage</a> to cache the assets and index files.
  <dt>Can I close the tab/browser?
  <dd>${canICloseTheTab()}
  <dt>What if I don't update a documentation?
  <dd>You'll see outdated content and some pages will be missing or broken, because the rest of the app (including data for the search and sidebar) uses a different caching mechanism that's updated automatically.
  <dt>I found a bug, where do I report it?
  <dd>In the <a href="https://github.com/freeCodeCamp/devdocs/issues">issue tracker</a>. Thanks!
  <dt>How do I uninstall/reset the app?
  <dd>Click <a href="#" data-behavior="reset">here</a>.
  <dt>Why aren't all documentations listed above?
  <dd>You have to <a href="/settings">enable</a> them first.
</dl>\
`;

var canICloseTheTab = function () {
  if (app.ServiceWorker.isEnabled()) {
    return ' Yes! Even offline, you can open a new tab, go to <a href="//devdocs.io">devdocs.io</a>, and everything will work as if you were online (provided you installed all the documentations you want to use beforehand). ';
  } else {
    let reason = "aren't available in your browser (or are disabled)";

    if (app.config.env !== "production") {
      reason =
        "are disabled in your development instance of DevDocs (enable them by setting the <code>ENABLE_SERVICE_WORKER</code> environment variable to <code>true</code>)";
    }

    return ` No. Service Workers ${reason}, so loading <a href="//devdocs.io">devdocs.io</a> offline won't work.<br>
The current tab will continue to function even when you go offline (provided you installed all the documentations beforehand). `;
  }
};

app.templates.offlineDoc = function (doc, status) {
  const outdated = doc.isOutdated(status);

  let html = `\
<tr data-slug="${doc.slug}"${outdated ? ' class="_highlight"' : ""}>
  <td class="_docs-name _icon-${doc.icon}">${doc.fullName}</td>
  <td class="_docs-size">${
    Math.ceil(doc.db_size / 100000) / 10
  }&nbsp;<small>MB</small></td>\
`;

  html += !(status && status.installed)
    ? `\
<td>-</td>
<td><button type="button" class="_btn-link" data-action="install">Install</button></td>\
`
    : outdated
      ? `\
<td><strong>Outdated</strong></td>
<td><button type="button" class="_btn-link _bold" data-action="update">Update</button> - <button type="button" class="_btn-link" data-action="uninstall">Uninstall</button></td>\
`
      : `\
<td>Up&#8209;to&#8209;date</td>
<td><button type="button" class="_btn-link" data-action="uninstall">Uninstall</button></td>\
`;

  return html + "</tr>";
};