Weight Chart at Google Calendar

weight.js

/**
 * Return calendar for weight.
 * @return Calendar
 */
function getWeightCal() {  
  var id = 'YOUR GOOGLE CALENDAR ID';
  var cal = CalendarApp.getOwnedCalendarById(id);
  return cal;
}

/**
 * Return start time.
 * @return Date
 */
function getStartTime(date) {
  if (date) return date;
  date = new Date();
  date.setMonth(date.getMonth() - 1);
  return date;
}

/**
 * Return end time.
 * @return Date
 */
function getEndTime(date) {
  if (date) return date;
  return new Date();
}

/**
 * @param Date startTime
 * @param Date endTime
 * @return boolean
 */
function invalidTime(startTime, endTime) {
  Logger.log("startTime: " + startTime + ", endTime: " + endTime);
  if (startTime.getTime() > endTime.getTime()) {
    return true;
  }
  return false;
}

/**
 * @param Date startTime
 * @param Date endTime
 * @param Array events
 */
function drawGraph(startTime, endTime, events) {
  if (!events || events.length == 0) {
    Browser.msgBox("データが1件もありません。データを登録してください。");
    return;
  }
  
  var weightRe = new RegExp("([0-9]+(?:[0-9]+)?)");
  var chartData = Charts.newDataTable()
      .addColumn(Charts.ColumnType.STRING, "Date")
      .addColumn(Charts.ColumnType.NUMBER, "Weight");
  for (var i = 0; i < events.length; i++) {
    var event = events[i];
    var date = event.getStartTime();
    var weight = false;
    
    if (!event.getTitle().match(weightRe)) {
      continue; 
    }
  
    weight = parseFloat(RegExp.$1);
    if (isNaN(weight)) {
      continue;
    }
    
    Logger.log("Date: " + date + ", Weight: " + weight);
    var d = date.getYear() + "/" + (date.getMonth()+1) + "/" + date.getDate();
    chartData.addRow([d, weight]);
  }
  
  showApp(startTime, endTime, chartData);
}

/**
 * @param Date startTime
 * @param Date endTime
 * @param DataTable chartData
 */
function showApp(startTime, endTime, chartData) {
  var chart = Charts.newAreaChart()
      .setDataTable(chartData.build())
      .setStacked()
      .setRange(0, 40)
      .setTitle("Weight")
      .build();
  
  var app = UiApp.createApplication().setTitle("Weight");
  
  var startTimeTextBox = app.createTextBox()
      .setName('startTime').setId('startTime')
      .setValue(startTime.getYear()+'/'+(startTime.getMonth()+1)+'/'+startTime.getDate());
  app.add(startTimeTextBox);
  
  var endTimeTextBox = app.createTextBox()
      .setName('endTime').setId('endTime')
      .setValue(endTime.getYear()+'/'+(endTime.getMonth()+1)+'/'+endTime.getDate());
  app.add(endTimeTextBox);

  var submitHandler = app.createServerClickHandler('handlerUpdateGraph')
      .addCallbackElement(startTimeTextBox)
      .addCallbackElement(endTimeTextBox);
  var submitButton = app.createButton("Update", submitHandler);
  app.add(submitButton);

  app.add(chart);
  
  var doc = SpreadsheetApp.getActive();
  doc.show(app);
}

/**
 * Click handler for update graph.
 * @param Event e
 */
function handlerUpdateGraph(e) {
  var dateRe = new RegExp("([0-9]{4})/([0-9]{1,2})/([0-9]{1,2})");
  var startTime = endTime = false;
  
  Logger.log(e);
  var st = e.parameter.startTime;
  if (st && st.match(dateRe)) startTime = new Date(RegExp.$1, parseInt(RegExp.$2,10)-1, RegExp.$3);
  var et = e.parameter.endTime;
  if (et && et.match(dateRe)) endTime = new Date(RegExp.$1, parseInt(RegExp.$2,10)-1, RegExp.$3);
  
  doUpdateGraph(startTime, endTime);
}

/**
 * Execute udpate weight graph.
 * @param Date startTime 
 */
function doUpdateGraph(startTime, endTime) {
  startTime = getStartTime(startTime);
  endTime = getEndTime(endTime);
  if (invalidTime(startTime, endTime)) {
    Browser.msgBox("日付が不正です。");
    return;
  }
  
  var cal = getWeightCal();
  var events = cal.getEvents(startTime, endTime);
  drawGraph(startTime, endTime, events);
}