Question

I have a google spreadsheet script which I run on a timed trigger, and have opted to receive notifications when it fails. If I run it manually it works fine, but when it triggers I receive the following notification:

Start Function Error Message Trigger End 9/28/12 9:45
PM plotPortfolioData TypeError: Cannot call method “getSheetByName” of
null. (line 5) time-based 9/28/12 9:45 PM

The problem is, line 5 is empty, and neither line 4 nor line 3 have any “getSheetByName” function

function plotPortfolioData() {

  // get the Portfolio Chart sheet, and create it if it doesn't exist
  var ss = SpreadsheetApp.getActiveSpreadsheet();

  var portfolioDataSetT = transpose(GetComprehensivePortfolioData(ss));

  varSheetName = "Charts";

  // IMPORTANT
  var firstIndividualStockColumn = 6; // first column in portfolioDataSetT where the actual individual holdings start

  // loop through every value in the portfolio dataset and replace 0 with a blank string (this has the effect of removing
  // any 0 quantity lines from the stacked charts).
  for (var i = 2; i != portfolioDataSetT.length; i++) // start at i = 2 to skip the header and first row (needed for charting)
  {
    for (ii in portfolioDataSetT[i])
    {
      if (portfolioDataSetT[i][ii] <= 0)
      {
        portfolioDataSetT[i][ii] = '';
      }
    }
  }


  if (!ss.getSheetByName(varSheetName))
  {
    var newSheetCreated = true;
    ss.insertSheet(varSheetName);
    var sheet = ss.getSheetByName(varSheetName);
  }
  else
  {
    var sheet = ss.getSheetByName(varSheetName);

    // remove all charts in this existing sheet
    var charts = sheet.getCharts();
    for (var i in charts)
    {
      sheet.removeChart(charts[i]);
    }
    var sheet = ss.getSheetByName(varSheetName);
  }

  // Build the data into the spreadsheet
  var sheetDataRange = sheet.getRange(1, 1, portfolioDataSetT.length, portfolioDataSetT[0].length);
  sheetDataRange.setValues(portfolioDataSetT);

  // prepare the pie chart data
  // start by listing the individual stock names vertically
  var number_of_custom_rows = 1; // the number of manual rows we will add that are not just stocks
  var pieChartSize = (portfolioDataSetT[0].length + 1 - firstIndividualStockColumn) + number_of_custom_rows; // number of holdings in the pie chart
  var pieChartFirstColumn = portfolioDataSetT[0].length+1; // just start after the data pile

  var pieChartStockTitles = sheet.getRange(1,1,1,portfolioDataSetT[0].length).getValues(); // the range of headers
  var pieChartHoldingsRange = sheet.getRange(portfolioDataSetT.length,1,1,portfolioDataSetT[0].length);
  var pieChartHoldings = pieChartHoldingsRange.getValues(); // range of holdings values

  // set the pie chart holdings range number format
  pieChartHoldingsRange.setNumberFormat("$#,###");

  var pieChartDataSpace = sheet.getRange(1,pieChartFirstColumn,pieChartSize,2); // the space where the pie chart data will be printed for graphing (2 columns for name and holding value for each stock)

  for (var i = 0; i != pieChartSize - number_of_custom_rows; i++)
  {
    pieChartDataSpace.getCell(i+1,1).setValue(pieChartStockTitles[0][firstIndividualStockColumn-1+i]); // add the name of the holding to the first pie chart column
    pieChartDataSpace.getCell(i+1,2).setValue(pieChartHoldings[0][firstIndividualStockColumn-1+i]); // add the value of the holding to the 2nd pie chart column
  }

  // now add the custom rows
  pieChartDataSpace.getCell(pieChartSize,1).setValue(pieChartStockTitles[0][4]); // add the cash header
  pieChartDataSpace.getCell(pieChartSize,2).setValue(pieChartHoldings[0][4]); // add the cash amount

  var chartHeight = 400;
  var chartWidth = 500;
  var offset = 3; // buffer region in pixels between charts and the edge of screen

  // hide the numbers for neatness:
  sheet.hideRows(1,portfolioDataSetT.length);

  // performance chart (top left)
  var performanceChart = sheet.newChart()
      .setOption('title', "Portfolio Measurements")
      .setPosition(portfolioDataSetT.length, 1, offset, offset)
      .setOption('height',chartHeight)
      .setOption('width',chartWidth)
      .setOption('lineWidth',1)
      //.setOption('vAxis.format',"$#,###")
      .setOption('vAxis.gridlines.count',10)
      .setOption('theme','maximized')
      .setChartType(Charts.ChartType.LINE)
      .addRange(sheet.getRange("A:D")) // date,cost base, cash-only,cost-base no cash
      .build();
  sheet.insertChart(performanceChart);

  // performance chart (bottom left)
  var compositionChart = sheet.newChart()
      .setChartType(Charts.ChartType.AREA)
      .setOption('title', "Portfolio Composition")
      .setPosition(portfolioDataSetT.length, 1, offset, 2*offset + chartHeight)
      .setOption('height',chartHeight)
      .setOption('width',chartWidth)
      .setOption('theme','maximized')
      .setOption('vAxis.gridlines.count',10)
      .setOption('isStacked',true)
      .setOption('lineWidth',0)
      .setOption('areaOpacity',0.8)
      //.setOption('vAxis.format',"$#,###")
      .addRange(sheet.getRange("A:A")) // dates
      .addRange(sheet.getRange("E:E")) // cash balance
      .addRange(sheet.getRange(1,firstIndividualStockColumn,portfolioDataSetT.length,portfolioDataSetT[0].length + 1 - firstIndividualStockColumn)) // add the individual stock holdings
      .build();
  sheet.insertChart(compositionChart);

  // pie chart portfolio composition (top right)
  var pieChart = sheet.newChart()
      .setChartType(Charts.ChartType.PIE)
      .setOption('title', "Portfolio Composition")
      .setPosition(portfolioDataSetT.length, 1, 2*offset + chartWidth, offset)
      .setOption('height',chartHeight)
      .setOption('width',chartWidth)
      .setOption('pieSliceText','label')
      .setOption('is3D',true)
      .addRange(sheet.getRange(1,pieChartFirstColumn,pieChartSize,1)) // add the individual stock names
      .addRange(sheet.getRange(1,pieChartFirstColumn+1,pieChartSize,1)) // add the individual holding values
      .build();
  sheet.insertChart(pieChart);

  // fix up number formatting
  var sheetWholeRange = sheet.getDataRange();
  sheetWholeRange.setNumberFormat("$#,###"); // set all numbers to currency
  var sheetDateRange = sheet.getRange("A:A");
  sheetDateRange.setNumberFormat("d-LLL-YYYY"); // set date column formatting
}

So, what’s going on, how am I supposed to debug this problem? When I run it, it works fine!

Answer 1

Seems the problem is in the following line

var ss = SpreadsheetApp.getActiveSpreadsheet();

When you start this script manually, I assume, you start if as a spreadsheet script from either the Spreadsheet Script Editor or the Spreadsheet Script Manager. In this case the getActiveSpreadsheet returns the active sheet which is opened now and ss is not null – everything is fine.

When you start the same script from a timed-trigger then there is no any active spreadsheet and the getActiveSpreadsheet() returns null. After that, probably, somewhere inside of the GetComprehensivePortfolioData method there is a line ss.getSheetByName('...'). In this line the exception is thrown.

I think, the GetComprehensivePortfolioData method is in a separate gs file and the first getSheetByName call is at the line 5.