Google Spreadsheet - How to get data from URL's headers, using CacheService and UrlFetchApp class services

urls-headers-cache-fetch.gs

/**
 * This script has been especially made for a particular context.
 * So use it with caution, and do not forget to customize it before any use.
 */

//globals
var sheet  = SpreadsheetApp.getActiveSpreadsheet(),
    sheets = sheet.getSheets();

/**
 * Retrieve header Response Code and Location from cache.
 */
function getDataFromCache(url) {
  var encodedUrl = encodeURIComponent(url),
      cache      = CacheService.getPublicCache();

  //get data from cache
  var details = cache.get(encodedUrl);

  //check cache
  if (details != null && details != []) {
    return details;
  }

  //get details from domainname.ext and www.domainname.ext
  var data    = getUrlDetails(url, false),
      datawww = getUrlDetails(url, true);

  //redefine details
  details = [];

  //store details
  if (data != null && datawww != null) {
    details.push(data.getResponseCode());
    details.push(data.getHeaders()['Location']);
    details.push(datawww.getResponseCode());
    details.push(datawww.getHeaders()['Location']);
  }

  //cache will be good for around 3600 seconds (1 hour)
  cache.put(encodedUrl, details, 3600);

  return details;
}

/**
 * Retrieve header Response Code and Location from URL depending on the subdomain "www".
 * All URLs are in normal HTTP protocol. No Secure protocol allowed.
 */
function getUrlDetails(url, www) {
  var fetch;

  try {
    fetch = UrlFetchApp.fetch("http://" + (www ? "www." : "") + url, {
      followRedirects: false,
      muteHttpExceptions: true
    });
  } catch(e) {}

  return fetch;
}

/**
 * Update URLS
 */
function main()
{
  //configurations
  var lineNumber   = 100,
      loadingMsg   = "...",
      currentSheet = sheets[2];

  //cells
  var cellmin = currentSheet.getRange("M2"),
      cellmax = currentSheet.getRange("N2");

  //check min
  var min = parseInt(cellmin.getValue(), 10),
      max = parseInt(cellmax.getValue(), 10);

  //works on min
  min = 4 > min ? 4 : min;
  cellmin.setValue(min);

  //works on max
  max = (min > max || max > (min + lineNumber) || max > 978) ? (min + lineNumber) : max;
  cellmax.setValue(max);

  //vars
  var val, check, cellh;

  //check URLS
  for (var i = min, len = max; i <= len; i++) {
    cellmax.setValue(i);
    cellh = currentSheet.getRange("H"+i);

    //get the value
    val = currentSheet.getRange("B"+i).getValue();
    check = cellh.getValue();

    //works on val
    val = loadingMsg == val ? "" : val;

    //check value
    if ("" == val || "" != check) {
      continue;
    }

    //loading
    currentSheet.getRange("H"+i).setValue(loadingMsg);

    //get complete url with schema
    var completeurl = "http://www." + val + "/";

    //get url headers for domain name w/out subdomain
    //details = [responseCode, location, wwwResponseCode, wwwLocation];
    var details = getDataFromCache(val);
    Logger.log(details);

    //loading
    cellh.setValue("");

    //check values
    if (4 == details.length) {
      //update data
      cellh.setValue(details[0]);
      currentSheet.getRange("I"+i).setValue(details[1]);
      currentSheet.getRange("J"+i).setValue(details[1] == completeurl ? "OK" : "KO");

      //update www.data
      currentSheet.getRange("K"+i).setValue(details[2]);
      currentSheet.getRange("L"+i).setValue(details[3]);
    }
  }
}