Sheets siderbar script

SERVER.gs

/**
 * Changes the variable validation if needed
 */

var validation = {
    sheet: 'Variabelen',
    range: 'E2:E12'
}

// Simple trigger for the onInstall event
function onInstall(e) {
  Keep.info('installed the addon');
  setProperties();/**
 * Changes the variable validation if needed
 */

var validation = {
    sheet: 'Variabelen',
    range: 'E2:E12'
}

// Simple trigger for the onInstall event
function onInstall(e) {
  Keep.info('installed the addon');
  setProperties();
  createTriggers();
  initialize(e);
}

// Create installable triggers for onOpen and onEdit
function createTriggers() {
  ScriptApp.newTrigger('initialize')
      .forSpreadsheet(spreadsheet)
      .onOpen()
      .create();
     
  ScriptApp.newTrigger('selectAction')
      .forSpreadsheet(spreadsheet)
      .onEdit()
      .create();
}


/**
 * Creates a menu entry in the Google Docs UI when the document is opened.
 *
 * @param {object} e The event parameter for a simple onOpen trigger. To
 *     determine which authorization mode (ScriptApp.AuthMode) the trigger is
 *     running in, inspect e.authMode.
 */
// function onOpen(e) {
function selectAction(e) {
  SpreadsheetApp.getUi().createMenu('Sidebar')
      .addItem('Show Sidebar', 'showSidebar')
      .addToUi();
      showSidebar();
}

/**
 * Opens a sidebar in the document containing the add-on's user interface.
 */

function showSidebar() {
    SpreadsheetApp.getUi()
        .showSidebar(HtmlService.createTemplateFromFile('SIDEBAR')
            .evaluate()
            .setSandboxMode(HtmlService.SandboxMode.IFRAME)
            .setTitle('Multiple selector'));
}

function getOptions() {
    return SpreadsheetApp.getActive().getSheetByName(validation.sheet).getRange(validation.range).getDisplayValues()
        .filter(String)
        .reduce(function(a, b) {
            return a.concat(b)
        })
}

function process(arr) {
    arr.length > 0 ? SpreadsheetApp.getActiveRange().clearContent().setValue(arr.join(", ")) :
        SpreadsheetApp.getUi().alert('No options selected')
}
  createTriggers();
  initialize(e);
}

// Create installable triggers for onOpen and onEdit
function createTriggers() {
  ScriptApp.newTrigger('initialize')
      .forSpreadsheet(spreadsheet)
      .onOpen()
      .create();
     
  ScriptApp.newTrigger('selectAction')
      .forSpreadsheet(spreadsheet)
      .onEdit()
      .create();
}


/**
 * Creates a menu entry in the Google Docs UI when the document is opened.
 *
 * @param {object} e The event parameter for a simple onOpen trigger. To
 *     determine which authorization mode (ScriptApp.AuthMode) the trigger is
 *     running in, inspect e.authMode.
 */
// function onOpen(e) {
function selectAction(e) {
  SpreadsheetApp.getUi().createMenu('Sidebar')
      .addItem('Show Sidebar', 'showSidebar')
      .addToUi();
      showSidebar();
}

/**
 * Opens a sidebar in the document containing the add-on's user interface.
 */

function showSidebar() {
    SpreadsheetApp.getUi()
        .showSidebar(HtmlService.createTemplateFromFile('SIDEBAR')
            .evaluate()
            .setSandboxMode(HtmlService.SandboxMode.IFRAME)
            .setTitle('Multiple selector'));
}

function getOptions() {
    return SpreadsheetApp.getActive().getSheetByName(validation.sheet).getRange(validation.range).getDisplayValues()
        .filter(String)
        .reduce(function(a, b) {
            return a.concat(b)
        })
}

function process(arr) {
    arr.length > 0 ? SpreadsheetApp.getActiveRange().clearContent().setValue(arr.join(", ")) :
        SpreadsheetApp.getUi().alert('No options selected')
}