GASによる永続化方法

1. main.gs

function main() {
  var count_before = loadCount();
  var count_today = getCountToday();
  var count_sum = count_before + count_today;
  
  Logger.log(count_sum);
  saveCount(count_sum);
}

function getCountToday() {
  return Math.floor(Math.random() * 10);
}

2. propertiesService.gs

var properties = PropertiesService.getScriptProperties();
//var properties = PropertiesService.getUserProperties();
//var properties = PropertiesService.getDocumentProperties();

function loadCount() {
  var count_s = properties.getProperty("Count");
  if (count_s == null) return 0;
  
  var count = parseInt(count_s, 10);
  if (isNaN(count)) return 0;
  return count;
}

function saveCount(count) {
  properties.setProperty("Count", count);
}

3. Spreadsheet.gs

var sheetUrl = "スプレッドシートのURL"; // https://docs.google.com/spreadsheets/d/～～～/edit#gid=0 みたいなの
var ss = SpreadsheetApp.openByUrl(sheetUrl);

function fetchListColumn(sheetName, column) {
  var sheet = ss.getSheetByName(sheetName);
  var num = Math.ceil(sheet.getRange("A1").getValue())
  var query = Utilities.formatString("%s1:%s%d",column,column,num);
  var raw = sheet.getRange(query).getValues();
  var list = Array(num);
  for (var i=0; i<list.length; i++) {
    list[i] = raw[i][0];
  }
  return list;
}

function readSettings() {
  var key = fetchListColumn("Settings", "B");
  var value = fetchListColumn("Settings", "C");
  var settings = {};
  for (var i=0; i<key.length; i++) {
    settings[key[i]] = value[i];
  }
  return settings;
}

function writeSettings(settings) {
  var keys = Object.keys(settings);
  var num = keys.length;
  var values = Array(num);
  for (var i=0; i<num;i++){
    values[i] = settings[keys[i]];
  }
  var content = [keys, values];
  content = transpose(content);
  
  var range = Utilities.formatString("B1:C%d",num);
  var sheet = ss.getSheetByName("Settings");
  sheet.getRange(range).setValues(content);
  
}

function transpose(arr) {
  var row = arr.length;
  var col = arr[0].length;
  
  var res = Array(col);
  for (var i = 0; i < col; i++) {
    res[i] = Array(row);
  }
  
  for (var i = 0; i < row; i++) {
    for (var j=0; j<col; j++) {
      res[j][i] = arr[i][j];
    }
  }
  return res;
}

var settings = readSettings();

function loadCount() {
  var value = settings["Count"];
  if (!value) return 0;
  return parseInt(value, 10);
}

function saveCount(count) {
  settings["Count"] = count;
  writeSettings(settings);
}

4. Drive.gs

var jsonName = "sample.json";
var settings = readJson(jsonName);

function getFile() {
  var query = 'title = "' + jsonName + '"';
  var files = DriveApp.searchFiles(query);
  if (files.hasNext()) {
    return files.next();
  }
  return DriveApp.createFile(name, "");
}

function readJson() {
  var file = getFile(jsonName);
  var content = file.getBlob().getDataAsString();
  if (!content) return {};
  var json = JSON.parse(content);
  return json;
}

function writeJson() {
  var content = JSON.stringify(settings);
  var file = getFile(jsonName);
  file.setContent(content);
}

function loadCount() {
  var count = settings["Count"];
  if (!count) return 0;
  return count;
}

function saveCount(count) {
  settings["Count"] = count;
  writeJson();
}