Userscript to download all of the logs on a Geocaching.com cache page as JSON

download-geocache-logs.user.js

// ==UserScript==
// @name        Download JSON cachelogs
// @namespace   dllogs.geocaching.danq.me
// @match       https://www.geocaching.com/geocache/*
// @grant       GM_registerMenuCommand
// @version     1.0
// @author      Dan Q
// @description Download all logs against a particular Geocaching.com geocache as a JSON file
// ==/UserScript==

function downloadLogsWrapper(){
  let logScroller;
  let cycleDuration = 100;
  let cyclesWaitedForLogsToLoad = 0;
  let maxCyclesWaitedForLogsToLoad = 30;
  let logScrollerDialog = document.createElement('dialog');
  logScrollerDialog.style.position = 'fixed';
  logScrollerDialog.style.left = 'calc(50% - 14vw)';
  logScrollerDialog.style.top = 'calc(50% - 5vh)';
  logScrollerDialog.style.height = '10vh';
  logScrollerDialog.style.width = '28vw';
  logScrollerDialog.style.display = 'grid';
  logScrollerDialog.style.placeContent = 'center';
  logScrollerDialog.style.textAlign = 'center';
  document.body.appendChild(logScrollerDialog);
  logScrollerDialog.innerHTML = 'Starting up...';
  logScrollerDialog.showModal();

  let footerRoot = document.getElementById('gc-footer-root');
  function scrollToGetMoreLogs(){
    logScrollerDialog.innerHTML = 'Scrolling to get more logs<br>';
    footerRoot.scrollIntoView();
    cyclesWaitedForLogsToLoad = 0;
    clearInterval(logScroller);
    logScroller = setInterval(maybeScrollToGetMoreLogs, cycleDuration);
  }

  function maybeScrollToGetMoreLogs(){
    cyclesWaitedForLogsToLoad++;
    logScrollerDialog.innerHTML += '.';
    let needToScroll = footerRoot.getBoundingClientRect().top > window.innerHeight;
    if(!needToScroll) {
      if(cyclesWaitedForLogsToLoad >= maxCyclesWaitedForLogsToLoad) {
        clearInterval(logScroller);
        downloadLogs();
      }
      return;
    }
    scrollToGetMoreLogs();
  }

  // kickstart process:
  setTimeout(scrollToGetMoreLogs, 100);

  function downloadLogs(){
    logScrollerDialog.innerHTML = 'Downloading logs as JSON';
    let gcCode = document.getElementById('ctl00_ContentBody_CoordInfoLinkControl1_uxCoordInfoCode').innerText.trim();
    let logData = Array.from(document.querySelectorAll('#cache_logs_table tbody tr')).map(tr=>{
      const author = tr.querySelector('.h5');
      return {
        cache: {
          name: document.getElementById('ctl00_ContentBody_CacheName').innerText.trim(),
          code: gcCode,
          type: document.querySelector('.cacheImage').attributes.title.value.trim(),
        },
        author: {
          name: author.innerText.trim(),
          guid: author.href.replace(/^.*\/profile\/\?guid=/, ''),
          premium: !!author.nextElementSibling.innerText.match(/Premium/),
        },
        log: {
          type: tr.querySelector('.h4').innerText.trim(),
          text: tr.querySelector('.LogText').innerText.trim(),
          date: tr.querySelector('.LogDate').innerText.trim(),
          luid: tr.querySelector('a[title="View Log"]').href.replace(/^.*\/seek\/log\.aspx\?LUID=/, ''),
        },
      };
    });
    let logDataEncoded = `data:text/json;charset=utf-8,${encodeURIComponent(JSON.stringify(logData))}`;
    let logDataLink = document.createElement('a');
    logDataLink.setAttribute("href", logDataEncoded);
    logDataLink.setAttribute("download", `${gcCode}.logs.json`);
    logDataLink.click();
    setTimeout(()=>logScrollerDialog.remove(), 1000);
  }
}

GM_registerMenuCommand('Download logs', downloadLogsWrapper);