Google Apps Script - Looging functions

logging.gs

/**
 * Logging and configuration functions adapted from the script:
 * 'A Google Apps Script for importing CSV data into a Google Spreadsheet' by Ian Lewis.
 *  https://gist.github.com/IanLewis/8310540
 * @author ianmlewis@gmail.com (Ian Lewis)
 * @author dunn.shane@gmail.com (Shane Dunn)
 * De Bortoli Wines July 2017
*/
/* =========== Globals ======================= */
/**
 * The output text that should be displayed in the log.
 * @private.
 */
var logArray_;

/* =========== Logging functions ======================= */

/**
 * Clears the in app log.
 * @private.
 */
function setupLog_() {
  logArray_ = [];
}

/**
 * Returns the log as a string.
 * @returns {string} The log.
 */
function getLog_() {
  return logArray_.join('\n'); 
}

/**
 * Appends a string as a new line to the log.
 * @param {String} value The value to add to the log.
 */
function log_(value) {
  logArray_.push(value);
  
  var app = UiApp.getActiveApplication();
  var foo = app.getElementById('log');
  foo.setText(getLog_());
}

/**
 * Displays the log in memory to the user.
 */
function displayLog_() {
  var uiLog = UiApp.createApplication().setTitle('Report Status').setWidth(400).setHeight(500);
  var panel = uiLog.createVerticalPanel();
  uiLog.add(panel);

  var txtOutput = uiLog.createTextArea().setId('log').setWidth('400').setHeight('500').setValue(getLog_());
  panel.add(txtOutput);
  
  SpreadsheetApp.getActiveSpreadsheet().show(uiLog); 
}